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As our understanding of the pathophysiology of diabetes evolves, we increasingly recognize that many patients may have a form of diabetes that does not neatly fit with a diagnosis of either type 1 or type 2 diabetes. The discovery and description of these forms of "atypical diabetes" have led to major contributions to our collective understanding of the basic biology that drives insulin secretion, insulin resistance, and islet autoimmunity. These discoveries now pave the way to a better classification of diabetes based on distinct endotypes. In this review, we highlight the key biological and clinical insights that can be gained from studying known forms of atypical diabetes. Additionally, we provide a framework for identification of patients with atypical diabetes based on their clinical, metabolic, and molecular features. Helpful clinical and genetic resources for evaluating patients suspected of having atypical diabetes are provided. Therefore, appreciating the various endotypes associated with atypical diabetes will enhance diagnostic accuracy and facilitate targeted treatment decisions. [ABSTRACT FROM AUTHOR]

OBJECTIVE: Determining the cause of severe insulin resistance and early-onset diabetes in the case of a young woman in which a wide range of differential diagnoses did not apply. RESEARCH DESIGN AND METHODS: Diagnostic workup including medical history, physical examination, specialist consultations, imaging methods, laboratory assessment, and genetic testing carried out by next-generation panel sequencing. RESULTS: After ruling out several differential diagnoses, genetic testing revealed a previously unknown homozygous variant within the canonical splice site of intron 4 in the WRN gene classified as pathogenic. Thus, although not all cardinal clinical criteria according to existing guidelines had been met, the phenotype of our patient was attributed to Werner syndrome (WS), an autosomal-recessive inherited progeroid syndrome. CONCLUSIONS: WS, although rare, must be considered as a differential diagnosis in cases of severe insulin resistance. Moreover, recognized clinical criteria of WS may not lead to diagnosis in all cases. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To explore whether insulin resistance, assessed by estimated glucose disposal rate (eGDR), is associated with cardiorenal risk and whether it modifies finerenone efficacy. RESEARCH DESIGN AND METHODS: In FIDELITY (N = 13,026), patients with type 2 diabetes, either 1) urine albumin-to-creatinine ratio (UACR) of ≥30 to <300 mg/g and estimated glomerular filtration rate (eGFR) of ≥25 to ≤90 mL/min/1.73 m2 or 2) UACR of ≥300 to ≤5,000 mg/g and eGFR of ≥25 mL/min/1.73 m2, who also received optimized renin-angiotensin system blockade, were randomized to finerenone or placebo. Outcomes included cardiovascular (cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for heart failure) and kidney (kidney failure, sustained decrease of ≥57% in eGFR from baseline, or renal death) composites. eGDR was calculated using waist circumference, hypertension status, and glycated hemoglobin for 12,964 patients. RESULTS: Median eGDR was 4.1 mg/kg/min. eGDR

ObjectiveThe autonomic nervous system (ANS) innervates pancreatic endocrine cells, muscle, and liver, all of which participate in glucose metabolism. We tested whether measures of cardiovascular ANS function are independently associated with incident diabetes and annual change in fasting glucose (FG) levels as well as with insulin secretion and insulin sensitivity in older adults without diabetes.Research design and methodsHeart rate (HR) and measures of HR variability (HRV) were derived from 24-h electrocardiographic monitoring. Blood pressure, seated and standing, was measured. Cox proportional hazards models and linear mixed models were used to analyze the associations between HRV, HR, and orthostatic hypotension (SBP >20 mmHg decline) and incident diabetes or longitudinal FG change.ResultsThe mean annual unadjusted FG change was 1 mg/dL. Higher detrended fluctuation analyses (DFA) values, averaged over 4-11 (DFA1) or 12-20 beats (DFA2)-reflecting greater versus less organization of beat-to-beat intervals-were associated with less FG increase over time (per 1-SD increment: DFA1: -0.49 mg/dL/year [-0.96, -0.03]; DFA2: -0.55 mg/dL/year [-1.02, -0.09]). In mutually adjusted analyses, higher SD of the N-N interval (SDNN) was associated with less FG increase over time (per 1-SD increment: SDNN: -0.62 mg/dL/year [-1.22, -0.03]). Higher values of DFA1, DFA2, and SDNN were each associated with greater insulin secretion and insulin sensitivity but not with incident diabetes. We observed no association of HR or orthostatic hypotension with diabetes or FG change.ConclusionsSpecific measures of cardiac autonomic function are prospectively related to FG level changes and insulin secretion and action.

OBJECTIVE: To explore the associations among mannose, indexes of insulin resistance (IR) and secretion, and long-term cardiovascular outcomes. RESEARCH DESIGN AND METHODS: Fasting mannose was assayed in 1,403 participants, one-half of which had a first myocardial infarction (MI) with either normal glucose tolerance (n = 1,045) or newly detected dysglycemia (i.e., impaired glucose tolerance or type 2 diabetes; n = 358). Regression models were used to explore mannose associations with surrogate indexes of IR/insulin secretion. Multivariate Cox models were used to investigate the independent association between high (higher quartile) versus low (lower three quartiles) mannose and major adverse cardiac events (MACE) (n = 163) during the 10-year follow-up. RESULTS: Mannose was independently associated with IR indexes (all P ≤ 0.001). High versus low mannose was independently associated with MACE (hazard ratio 1.54, 95% CI 1.07–2.20) in the overall population. CONCLUSIONS: Mannose might represent a new biomarker able to track early, potentially detrimental glucometabolic alterations independently of glycemic state. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To evaluate changes in insulin physiology in euglycemic pregnancy and gestational diabetes mellitus (GDM). RESEARCH DESIGN AND METHODS: Participants underwent oral glucose tolerance tests at ≤15 weeks' gestation (early pregnancy), 24–32 weeks' gestation (mid-late pregnancy), and 6–24 weeks postpartum. We evaluated longitudinal changes in insulin secretory response (log Stumvoll first-phase estimate) and insulin sensitivity (log Matsuda index) using linear mixed models. We then evaluated participants who met GDM criteria in early pregnancy (early GDM) and mid-late pregnancy (classic GDM) separately from those without GDM. We derived the pregnancy insulin physiology (PIP) index to quantify β-cell compensation for insulin resistance. RESULTS: Among 166 participants, 21 had early GDM and 24 developed classic GDM. Insulin sensitivity was reduced slightly in early pregnancy (β = −0.20, P < 0.001) and substantially in mid-late pregnancy (β = −0.47, P < 0.001) compared with postpartum. Insulin secretory response (adjusted for insulin sensitivity) was augmented in early pregnancy (β = 0.16, P < 0.001) and mid-late pregnancy (β = 0.16, P = 0.001) compared with postpartum. Compared with postpartum, the PIP index was augmented in early pregnancy (β = 215, P = 0.04) but not mid-late pregnancy (β = 55, P = 0.64). Early GDM was distinguished by a substantial reduction in early pregnancy insulin sensitivity (β = −0.59, P < 0.001) compared with postpartum. Both early and classic GDM lacked evidence of early pregnancy augmentation of insulin secretory response (adjusted for insulin sensitivity) and the PIP index (P > 0.1 vs. postpartum). Early pregnancy PIP index predicted GDM independent of participant characteristics (area under the curve without PIP index 0.70 [95% CI 0.61–0.79], area under the curve with PIP index 0.87 [95% CI 0.80–0.93]). CONCLUSIONS: β-Cell function is enhanced in early pregnancy. Deficient first-trimester β-cell function predicts GDM. [ABSTRACT FROM AUTHOR]

ObjectiveWe investigated sex and racial differences in insulin sensitivity, β-cell function, and glycated hemoglobin (HbA1c) and the associations with selected phenotypic characteristics.Research design and methodsThis is a cross-sectional analysis of baseline data from 3,108 GRADE (Glycemia Reduction Approaches in Diabetes: A Comparative Effectiveness Study) participants. All had type 2 diabetes diagnosed

ObjectiveDisruption of rest-activity rhythms is cross-sectionally associated with metabolic disorders, including type 2 diabetes, yet it remains unclear whether it predicts impaired glucose metabolism and homeostasis. The aim of this study is to examine the cross-sectional and prospective associations between rest-activity rhythm characteristics and glycemic measures in a cohort of older men.Research design and methodsBaseline rest-activity rhythms were derived from actigraphy with use of extended cosine model analysis. With subjects fasting, glucose, insulin, and HOMA of insulin resistance (HOMA-IR) were measured from blood at baseline and after ∼3.5 years. Type 2 diabetes was defined based on self-report, medication use, and fasting glucose.ResultsIn the cross-sectional analysis (n = 2,450), lower 24-h amplitude-to-mesor ratio (i.e., mean activity-adjusted rhythm amplitude) and reduced overall rhythmicity were associated with higher fasting insulin and HOMA-IR (all P trend < 0.0001), indicating increased insulin resistance. The odds of baseline type 2 diabetes were significantly higher among those in the lowest quartile of amplitude (Q1) (odds ratio [OR]Q1 vs. Q4 1.63 [95% CI 1.14, 2.30]) and late acrophase group (ORlate vs. normal 1.46 [95% CI 1.04, 2.04]). In the prospective analysis (n = 861), multiple rest-activity characteristics predicted a two- to threefold increase in type 2 diabetes risk, including a lower amplitude (ORQ1 vs. Q4 3.81 [95% CI 1.45, 10.00]) and amplitude-to-mesor ratio (OR 2.79 [95% CI 1.10, 7.07]), reduced overall rhythmicity (OR 3.49 [95% CI 1.34, 9.10]), and a late acrophase (OR 2.44 [1.09, 5.47]).ConclusionsRest-activity rhythm characteristics are associated with impaired glycemic metabolism and homeostasis and higher risk of incident type 2 diabetes.

ObjectiveExperimental studies have implicated soluble (s)CD14, an effector of lipopolysaccharide-induced inflammation, in insulin resistance, but its role in human metabolic endotoxemia has not been studied. We evaluated sCD14 in relation to dysglycemia in older adults and how this compares to other markers of inflammation.Research design and methodsWe investigated associations of sCD14, interleukin-6 (IL-6), CRP, and white blood cell (WBC) count with insulin resistance (quantitative insulin-sensitivity check index and HOMA 2 of insulin resistance) and incident type 2 diabetes in a population-based cohort of older adults. We also assessed the causal role of sCD14 in insulin resistance using an instrumental variable approach by Mendelian randomization.ResultsAfter adjustment for conventional risk factors, each of the four biomarkers showed positive cross-sectional associations with both insulin resistance measures. These associations persisted after mutual adjustment for all markers except sCD14. Over a median follow-up of 11.6 years, 466 cases of diabetes occurred. All biomarkers except sCD14 were positively associated with diabetes, although only WBC count remained associated (hazard ratio 1.43 per doubling [95% CI 1.07, 1.90]) after mutual adjustment. Instrumental variable analysis did not support a causal role for sCD14 in insulin resistance.ConclusionsAmong older adults, sCD14 was associated with insulin resistance, but this disappeared after adjustment for other biomarkers, showed no evidence of a causal basis, and was not accompanied by a similar association with diabetes. IL-6, CRP, and WBC count were each associated with insulin resistance and diabetes, WBC count most robustly. These findings do not support a central role for sCD14, but they highlight the preeminence of WBC count as an inflammatory measure of diabetes risk in this population.

Objective: Hyperglycemia can increase urinary zinc excretion. We evaluated the association of higher urinary zinc level with new diagnosis of incident type 2 diabetes mellitus (T2DM) in adult populations with a high burden of T2DM from AZ, OK, and ND and SD. We also assessed the cross-sectional association of urinary zinc levels with prevalent prediabetes.Research Design and Methods: We included 1,339 adults free of T2DM at baseline (1989-1991) followed through 1998-1999 in the Strong Heart Study (SHS) and 1,905 family members of SHS participants followed as part of the Strong Heart Family Study (SHFS) through 2006-2009.Results: T2DM incidence was 14.7% (mean follow-up 6.6 years) in the SHS and 13.5% (mean follow-up 5.6 years) in the SHFS. After adjustment for sex, site, education, smoking status, BMI, and estimated glomerular filtration rate, the hazard ratio of T2DM in comparing 75th vs. 25th percentiles of urinary zinc distribution was 1.21 (95% CI 1.08, 1.36) in the SHS and 1.12 (0.96, 1.31) in the SHFS. These associations were attenuated but significant in the SHS after adjustment for HOMA of insulin resistance (HOMA-IR) score. With exclusion of participants with prediabetes at baseline, urinary zinc remained significantly associated with T2DM in the SHS. In cross-sectional analyses, prediabetes was associated with higher urinary zinc levels.Conclusions: Urinary zinc levels were associated with T2DM incidence and prediabetes prevalence even after adjustment for HOMA-IR in populations with a high burden of T2DM. These results highlight the importance of zinc metabolism in diabetes development. [ABSTRACT FROM AUTHOR]

Objective: Experimental studies suggest that excess serum free fatty acid (FFA) levels result in impaired glucose metabolism. This study investigated the relationship between changes in serum FFA levels after glucose intake and type 2 diabetes risk.Research Design and Methods: This observational study included 6,800 individuals without diabetes who underwent a 75-g oral glucose tolerance test. Serum FFA levels were measured before and 30 and 60 min after glucose intake. The percentages of changes in serum FFA levels from 0 to 30 and from 30 to 60 min were compared, and a low rate of change in FFA levels was determined using the receiver operating characteristic curve analysis.Results: Over a mean 5.3-year follow-up period, 485 participants developed type 2 diabetes. After adjusting for plasma glucose levels and indices of insulin resistance and β-cell function, low rates of change in FFA levels at 0-30 min (adjusted odds ratio [aOR] 1.91; 95% CI 1.54-2.37) and 30-60 min (aOR 1.48; 95% CI 1.15-1.90) were associated with the incidence of type 2 diabetes. Stratified analysis revealed that the low rate of change in FFA levels at 30-60 min (aOR 1.97; 95% CI 1.05-3.69) was associated with the incidence of type 2 diabetes even in participants with normal fasting glucose levels or glucose tolerance.Conclusions: Changes in serum FFA levels within the 1st h after glucose intake could be a primary predictor of type 2 diabetes. This change may occur prior to the onset of impaired glucose metabolism. [ABSTRACT FROM AUTHOR]

Objective: This analysis of 3,375 adults with overweight/obesity across the Semaglutide Treatment Effect in People with obesity (STEP) 1, 3, and 4 trials evaluated whether more participants with prediabetes had normoglycemia after 68 weeks' treatment with once-weekly semaglutide 2.4 mg plus lifestyle intervention versus placebo and assessed changes in glucose metabolism in participants with prediabetes.Research Design and Methods: STEP 1, 3, and 4 were phase 3, 68-week, randomized, placebo-controlled, multinational trials; STEP 4 had a 20-week semaglutide run-in and 48-week randomized period. Analyses included changes (week 0-68; before the washout period) in glycemic status (prespecified: STEP 1 and 3; post hoc: STEP 4), and in HbA1c, fasting plasma glucose (FPG), and HOMA insulin resistance (HOMA-IR) among participants with prediabetes (post hoc).Results: Significantly more participants with baseline (week 0) prediabetes (n = 1,536) had normoglycemia at week 68 with semaglutide versus placebo (STEP 1, 84.1% vs. 47.8%; STEP 3, 89.5% vs. 55.0%; STEP 4, 89.8% vs. 70.4%; all P < 0.0001). Fewer participants with baseline normoglycemia had prediabetes at week 68 with semaglutide versus placebo (STEP 1, 2.9% vs. 10.9%; STEP 3, 3.2% vs. 5.8%; STEP 4, 1.1% vs. 5.0%). Semaglutide resulted in greater improvements in HbA1c, FPG, and HOMA-IR than placebo among participants with baseline prediabetes (all P < 0.01).Conclusions: STEP 1, 3, and 4 collectively provide a robust assessment of the effects of semaglutide on glucose metabolism and prediabetes in a large cohort of adults with overweight/obesity while on treatment. Among participants with baseline prediabetes, 68 weeks' treatment with semaglutide versus placebo led to significant improvements in glucose metabolism and a higher likelihood of normoglycemia. [ABSTRACT FROM AUTHOR]

Objective: The optimal screening strategy for dysglycemia (including type 2 diabetes and impaired glucose tolerance) in patients with coronary artery disease (CAD) is debated. We tested the hypothesis that measures of insulin resistance by HOMA indexes may constitute good screening methods.Research Design and Methods: Insulin, C-peptide, glycated hemoglobin A1c, and an oral glucose tolerance test (OGTT) were centrally assessed in 3,534 patients with CAD without known dysglycemia from the fifth European Survey of Cardiovascular Disease Prevention and Diabetes (EUROASPIRE V). Three different HOMA indexes were calculated: HOMA of insulin resistance (HOMA-IR), HOMA2 based on insulin (HOMA2-ins), and HOMA2 based on C-peptide (HOMA2-Cpep). Dysglycemia was diagnosed based on the 2-h postload glucose value obtained from the OGTT. Information on study participants was obtained by standardized interviews. The optimal thresholds of the three HOMA indexes for dysglycemia diagnosis were obtained by the maximum value of Youden's J statistic on receiver operator characteristic curves. Their correlation with clinical parameters was assessed by Spearman coefficients.Results: Of 3,534 patients with CAD (mean age 63 years; 25% women), 41% had dysglycemia. Mean insulin, C-peptide, and HOMA indexes were significantly higher in patients with versus without newly detected dysglycemia (all P < 0.0001). Sensitivity and specificity of the three HOMA indexes for the diagnosis of dysglycemia were low, but their correlation with BMI and waist circumference was strong.Conclusions: Screening for dysglycemia in patients with CAD by HOMA-IR, HOMA2-ins, and HOMA2-Cpep had insufficient diagnostic performance to detect dysglycemia with reference to the yield of an OGTT, which should still be prioritized despite its practical drawbacks. [ABSTRACT FROM AUTHOR]

Objective: To investigate whether the association between insulin resistance and cardiovascular disease (CVD) differs by glucose tolerance status.Research Design and Methods: We analyzed a nationwide sample of 111,576 adults without CVD at baseline, using data from the China Cardiometabolic Disease and Cancer Cohort Study. Insulin resistance was estimated by sex-specific HOMA of insulin resistance (HOMA-IR) quartiles for participants with normal glucose tolerance, prediabetes, or diabetes, separately, and by 1 SD of HOMA-IR for the overall study participants. We used Cox proportional hazards models to examine the association between insulin resistance and incident CVD according to glucose tolerance status and evaluate the CVD risk associated with the combined categories of insulin resistance and obesity in prediabetes and diabetes, as compared with normal glucose tolerance. Models were adjusted for age, sex, education attainment, alcohol drinking, smoking, physical activity, and diet quality.Results: In participants with normal glucose tolerance, prediabetes, and diabetes defined by three glucose parameters, multivariable-adjusted hazard ratios (95% CIs) for incident CVD associated with the highest versus the lowest quartile of HOMA-IR were 1.03 (0.82-1.30), 1.23 (1.07-1.42), and 1.61 (1.30-2.00), respectively; the corresponding values for CVD per 1-SD increase in HOMA-IR were 1.04 (0.92-1.18), 1.12 (1.06-1.18), and 1.15 (1.09-1.21), respectively (P for interaction = 0.011). Compared with participants with normal glucose tolerance, in participants with prediabetes, the combination of the highest HOMA-IR quartile and obesity showed 17% (95% CI 2-34%) higher risk of CVD, while the combination of the lowest two HOMA-IR quartiles and nonobesity showed 15-17% lower risk of CVD. In participants with diabetes, the upper two HOMA-IR quartiles exhibited 44-77% higher risk of CVD, regardless of obesity status. Consistent findings were observed for glucose tolerance status defined by different combinations of glycemic parameters.Conclusions: Glucose intolerance status exacerbated the association between insulin resistance and CVD risk. Compared with adults with normal glucose tolerance, adults with prediabetes who were both insulin resistant and obese exhibited higher risks of CVD, while in adults with diabetes, the CVD risk related to insulin resistance remained, regardless of obesity. [ABSTRACT FROM AUTHOR]

Objective: In a large, multiethnic cohort of youths with obesity, we analyzed pathophysiological and genetic mechanisms underlying variations in plasma glucose responses to a 180 min oral glucose tolerance test (OGTT).Research Design and Methods: Latent class trajectory analysis was used to identify various glucose response profiles to a nine-point OGTT in 2,378 participants in the Yale Pathogenesis of Youth-Onset T2D study, of whom 1,190 had available TCF7L2 genotyping and 358 had multiple OGTTs over a 5 year follow-up. Insulin sensitivity, clearance, and β-cell function were estimated by glucose, insulin, and C-peptide modeling.Results: Four latent classes (1 to 4) were identified based on increasing areas under the curve for glucose. Participants in class 3 and 4 had the worst metabolic and genetic risk profiles, featuring impaired insulin sensitivity, clearance, and β-cell function. Model-predicted probability to be classified as class 1 and 4 increased across ages, while insulin sensitivity and clearance showed transient reductions and β-cell function progressively declined. Insulin sensitivity was the strongest determinant of class assignment at enrollment and of the longitudinal change from class 1 and 2 to higher classes. Transitions between classes 3 and 4 were explained only by changes in β-cell glucose sensitivity.Conclusions: We identified four glucose response classes in youths with obesity with different genetic risk profiles and progressive impairment in insulin kinetics and action. Insulin sensitivity was the main determinant in the transition between lower and higher glucose classes across ages. In contrast, transitions between the two worst glucose classes were driven only by β-cell glucose sensitivity. [ABSTRACT FROM AUTHOR]

Objective: To analyze the relationship between time-serial changes in insulin resistance and renal outcomes.Research Design and Methods: A prospective cohort of subjects from the general population without chronic kidney disease (CKD) underwent a biennial checkup for 12 years (n = 5,347). The 12-year duration was divided into a 6-year exposure period, where distinct HOMA for insulin resistance (HOMA-IR) trajectories were identified using latent variable mixture modeling, followed by a 6-year event accrual period, from which the renal outcome data were analyzed. The primary end point was adverse renal outcomes, defined as a composite of estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2 in two or more consecutive checkups or albumin ≥1+ on urine strip.Results: Two distinct groups of HOMA-IR trajectories were identified during the exposure period: stable (n = 4,770) and increasing (n = 577). During the event accrual period, 449 patients (8.4%) developed adverse renal outcomes, and the risk was higher in the increasing HOMA-IR trajectory group than in the stable group (hazard ratio 2.06, 95% CI 1.62-2.60, P < 0.001). The results were similar after adjustment for baseline clinical characteristics, comorbidities, anthropometric and laboratory findings, eGFR, and HOMA-IR. The clinical significance of increasing HOMA-IR trajectory was similar in three or four HOMA-IR trajectories. The increasing tendency of HOMA-IR was persistently associated with a higher incidence of adverse renal outcomes, irrespective of the prevalence of diabetes.Conclusions: An increasing tendency of insulin resistance was associated with a higher risk of adverse renal outcomes. Time-serial tracking of insulin resistance may help identify patients at high risk for CKD. [ABSTRACT FROM AUTHOR]

Objective: Genetic risk scores (GRS) aid classification of diabetes type in White European adult populations. We aimed to assess the utility of GRS in the classification of diabetes type among racially/ethnically diverse youth in the U.S.Research Design and Methods: We generated type 1 diabetes (T1D)- and type 2 diabetes (T2D)-specific GRS in 2,045 individuals from the SEARCH for Diabetes in Youth study. We assessed the distribution of genetic risk stratified by diabetes autoantibody positive or negative (DAA+/-) and insulin sensitivity (IS) or insulin resistance (IR) and self-reported race/ethnicity (White, Black, Hispanic, and other).Results: T1D and T2D GRS were strong independent predictors of etiologic type. The T1D GRS was highest in the DAA+/IS group and lowest in the DAA-/IR group, with the inverse relationship observed with the T2D GRS. Discrimination was similar across all racial/ethnic groups but showed differences in score distribution. Clustering by combined genetic risk showed DAA+/IR and DAA-/IS individuals had a greater probability of T1D than T2D. In DAA- individuals, genetic probability of T1D identified individuals most likely to progress to absolute insulin deficiency.Conclusions: Diabetes type-specific GRS are consistent predictors of diabetes type across racial/ethnic groups in a U.S. youth cohort, but future work needs to account for differences in GRS distribution by ancestry. T1D and T2D GRS may have particular utility for classification of DAA- children. [ABSTRACT FROM AUTHOR]

Objective: We tested whether the concurrence of food intake and elevated concentrations of endogenous melatonin, as occurs with late eating, results in impaired glucose control, in particular in carriers of the type 2 diabetes-associated G allele in the melatonin receptor-1B gene (MTNR1B).Research Design and Methods: In a Spanish natural late-eating population, a randomized, crossover study was performed. Each participant (n = 845) underwent two evening 2-h 75-g oral glucose tolerance tests following an 8-h fast: an early condition scheduled 4 h prior to habitual bedtime ("early dinner timing") and a late condition scheduled 1 h prior to habitual bedtime ("late dinner timing"), simulating an early and a late dinner timing, respectively. Differences in postprandial glucose and insulin responses between early and late dinner timing were determined using incremental area under the curve (AUC) calculated by the trapezoidal method.Results: Melatonin serum levels were 3.5-fold higher in the late versus early condition, with late dinner timing resulting in 6.7% lower insulin AUC and 8.3% higher glucose AUC. The effect of late eating impairing glucose tolerance was stronger in the MTNR1B G-allele carriers than in noncarriers. Genotype differences in glucose tolerance were attributed to reductions in β-cell function (P for interaction, Pint glucose area under the curve = 0.009, Pint corrected insulin response = 0.022, and Pint disposition index = 0.018).Conclusions: Concurrently high endogenous melatonin and carbohydrate intake, as typical for late eating, impairs glucose tolerance, especially in MTNR1B G-risk allele carriers, attributable to insulin secretion defects. [ABSTRACT FROM AUTHOR]

Objective: The role of the gut in diabetes remission after Roux-en-Y gastric bypass (RYGB) is incompletely understood. We assessed the temporal change in insulin secretory capacity after RYGB, using oral and intravenous (IV) glucose, in individuals with type 2 diabetes.Research Design and Methods: Longitudinal, prospective measures of β-cell function were assessed after oral glucose intake and graded glucose infusion in individuals with severe obesity and diabetes studied at 0, 3 (n = 29), 12 (n = 24), and 24 (n = 20) months after RYGB. Data were collected between 2015 and 2019 in an academic clinical research center.Results: The decreases in body weight, fat mass, waist circumference, and insulin resistance after surgery (all P < 0.001 at 12 and 24 months) did not differ according to diabetes remission status. In contrast, both the magnitude and temporal changes in β-cell glucose sensitivity after oral glucose intake differed by remission status (P = 0.04): greater (6.5-fold; P < 0.01) and sustained in those in full remission, moderate and not sustained past 12 months in those with partial remission (3.3-fold; P < 0.001), and minimal in those not experiencing remission (2.7-fold; P = not significant). The improvement in β-cell function after IV glucose administration was not apparent until 12 months, significant only in those in full remission, and only ∼33% of that observed after oral glucose intake. Preintervention β-cell function and its change after surgery predicted remission; weight loss and insulin sensitivity did not.Conclusions: Our data show the time course of changes in β-cell function after RYGB. The improvement in β-cell function after RYGB, but not changes in weight loss or insulin sensitivity, drives diabetes remission. [ABSTRACT FROM AUTHOR]

Objective: Preclinical research implicates hypothalamic glial cell responses in the pathogenesis of obesity and type 2 diabetes (T2D). In the current study we sought to translate such findings to humans by testing whether radiologic markers of gliosis in the mediobasal hypothalamus (MBH) were greater in individuals with obesity and impaired glucose homeostasis or T2D.Research Design and Methods: Using cross-sectional and prospective cohort study designs, we applied a validated quantitative MRI approach to assess gliosis in 67 adults with obesity and normal glucose tolerance, impaired glucose tolerance (IGT), or T2D. Assessments of glucose homeostasis were conducted via oral glucose tolerance tests (OGTT) and β-cell modeling.Results: We found significantly greater T2 relaxation times (a marker of gliosis by MRI), that were independent of adiposity, in the groups with IGT and T2D as compared with the group with normal glucose tolerance. Findings were present in the MBH, but not control regions. Moreover, positive linear associations were present in the MBH but not control regions between T2 relaxation time and glucose area under the curve during an OGTT, fasting glucose concentrations, hemoglobin A1c, and visceral adipose tissue mass, whereas negative linear relationships were present in the MBH for markers of insulin sensitivity and β-cell function. In a prospective cohort study, greater MBH T2 relaxation times predicted declining insulin sensitivity over 1 year.Conclusions: Findings support a role for hypothalamic gliosis in the progression of insulin resistance in obesity and thus T2D pathogenesis in humans. [ABSTRACT FROM AUTHOR]

Objective: Insulin action in the human brain reduces food intake, improves whole-body insulin sensitivity, and modulates body fat mass and its distribution. Obesity and type 2 diabetes are often associated with brain insulin resistance, resulting in impaired brain-derived modulation of peripheral metabolism. So far, no pharmacological treatment for brain insulin resistance has been established. Since sodium-glucose cotransporter 2 (SGLT2) inhibitors lower glucose levels and modulate energy metabolism, we hypothesized that SGLT2 inhibition may be a pharmacological approach to reverse brain insulin resistance.Research Design and Methods: In this randomized, double-blind, placebo-controlled clinical trial, 40 patients (mean ± SD; age 60 ± 9 years; BMI 31.5 ± 3.8 kg/m2) with prediabetes were randomized to receive 25 mg empagliflozin every day or placebo. Before and after 8 weeks of treatment, brain insulin sensitivity was assessed by functional MRI combined with intranasal administration of insulin to the brain.Results: We identified a significant interaction between time and treatment in the hypothalamic response to insulin. Post hoc analyses revealed that only empagliflozin-treated patients experienced increased hypothalamic insulin responsiveness. Hypothalamic insulin action significantly mediated the empagliflozin-induced decrease in fasting glucose and liver fat.Conclusions: Our results corroborate insulin resistance of the hypothalamus in humans with prediabetes. Treatment with empagliflozin for 8 weeks was able to restore hypothalamic insulin sensitivity, a favorable response that could contribute to the beneficial effects of SGLT2 inhibitors. Our findings position SGLT2 inhibition as the first pharmacological approach to reverse brain insulin resistance, with potential benefits for adiposity and whole-body metabolism. [ABSTRACT FROM AUTHOR]

Objective: To assess the relationship between body fat distribution and incident lower-extremity arterial disease (LEAD).Research Design and Methods: We included 155,925 postmenopausal women with anthropometric measures from the Women's Health Initiative who had no known LEAD at recruitment. A subset of 10,894 participants had body composition data quantified by DXA. Incident cases of symptomatic LEAD were ascertained and adjudicated through medical record review.Results: We identified 1,152 incident cases of LEAD during a median 18.8 years follow-up. After multivariable adjustment and mutual adjustment, waist and hip circumferences were positively and inversely associated with risk of LEAD, respectively (both P-trend < 0.0001). In a subset (n = 22,561) where various cardiometabolic biomarkers were quantified, a similar positive association of waist circumference with risk of LEAD was eliminated after adjustment for diabetes and HOMA of insulin resistance (P-trend = 0.89), whereas hip circumference remained inversely associated with the risk after adjustment for major cardiometabolic traits (P-trend = 0.0031). In the DXA subset, higher trunk fat (P-trend = 0.0081) and higher leg fat (P-trend < 0.0001) were associated with higher and lower risk of LEAD, respectively. Further adjustment for diabetes, dyslipidemia, and blood pressure diminished the association for trunk fat (P-trend = 0.49), yet the inverse association for leg fat persisted (P-trend = 0.0082).Conclusions: Among U.S. postmenopausal women, a positive association of upper-body fat with risk of LEAD appeared to be attributable to traditional risk factors, especially insulin resistance. Lower-body fat was inversely associated with risk of LEAD beyond known risk factors. [ABSTRACT FROM AUTHOR]

Objective: Endogenous insulin clearance (EIC) is physiologically reduced at increasing insulin secretion rate (ISR). Computing EIC at the prevailing ISR does not distinguish the effects of hypersecretion from those of other mechanisms of glucose homeostasis. We aimed to measure EIC in standardized ISR conditions (i.e., at fixed ISR levels) and to analyze its associations with relevant physiologic factors.Research Design and Methods: We estimated standardized EIC (EICISR) by mathematical modeling in nine different studies with insulin and glucose infusions (N = 2,067). EICISR association with various traits was analyzed by stepwise multivariable regression in studies with both euglycemic clamp and oral glucose tolerance test (OGTT) (N = 1,410). We also tested whether oral glucose ingestion, as opposed to intravenous infusion, has an independent effect on EIC (N = 1,555).Results: Insulin sensitivity (as M/I from the euglycemic clamp) is the strongest determinant of EICISR, approximately four times more influential than insulin resistance-related hypersecretion. EICISR independently associates positively with M/I, fasting and mean OGTT glucose or type 2 diabetes, and β-cell glucose sensitivity and negatively with African American or Hispanic race, female sex, and female age. With oral glucose ingestion, an ISR-independent ∼10% EIC reduction is necessary to explain the observed insulin concentration profiles.Conclusions: Based on EICISR, we posit the existence of two adaptive processes involving insulin clearance: the first reduces EICISR with insulin resistance (not with higher BMI per se) and is more relevant than the concomitant hypersecretion; the second reduces EICISR with β-cell dysfunction. These processes are dysregulated in type 2 diabetes. Finally, oral glucose ingestion per se reduces insulin clearance. [ABSTRACT FROM AUTHOR]

Objective: To identify predictors of glycemic worsening among youth and adults with impaired glucose tolerance (IGT) or recently diagnosed type 2 diabetes in the Restoring Insulin Secretion (RISE) Study.Research Design and Methods: A total of 91 youth (10-19 years) were randomized 1:1 to 12 months of metformin (MET) or 3 months of glargine, followed by 9 months of metformin (G-MET), and 267 adults were randomized to MET, G-MET, liraglutide plus MET (LIRA+MET), or placebo for 12 months. All participants underwent a baseline hyperglycemic clamp and a 3-h oral glucose tolerance test (OGTT) at baseline, month 6, month 12, and off treatment at month 15 and month 21. Cox models identified baseline predictors of glycemic worsening (HbA1c increase ≥0.5% from baseline).Results: Glycemic worsening occurred in 17.8% of youth versus 7.5% of adults at month 12 (P = 0.008) and in 36% of youth versus 20% of adults at month 21 (P = 0.002). In youth, glycemic worsening did not differ by treatment. In adults, month 12 glycemic worsening was less on LIRA+MET versus placebo (hazard ratio 0.21, 95% CI 0.05-0.96, P = 0.044). In both age-groups, lower baseline clamp-derived β-cell responses predicted month 12 and month 21 glycemic worsening (P < 0.01). Lower baseline OGTT-derived β-cell responses predicted month 21 worsening (P < 0.05). In youth, higher baseline HbA1c and 2-h glucose predicted month 12 and month 21 glycemic worsening, and higher fasting glucose predicted month 21 worsening (P < 0.05). In adults, lower clamp- and OGTT-derived insulin sensitivity predicted month 12 and month 21 worsening (P < 0.05).Conclusions: Glycemic worsening was more common among youth than adults with IGT or recently diagnosed type 2 diabetes, predicted by lower baseline β-cell responses in both groups, hyperglycemia in youth, and insulin resistance in adults. [ABSTRACT FROM AUTHOR]

Objective: We aimed to test whether type 2 diabetes (T2D)-associated TCF7L2 genetic variants affect insulin sensitivity or secretion in autoantibody-positive relatives at risk for type 1 diabetes (T1D).Research Design and Methods: We studied autoantibody-positive TrialNet Pathway to Prevention study participants (N = 1,061) (mean age 16.3 years) with TCF7L2 single nucleotide polymorphism (SNP) information and baseline oral glucose tolerance test (OGTT) to calculate indices of insulin sensitivity and secretion. With Bonferroni correction for multiple comparisons, P values < 0.0086 were considered statistically significant.Results: None, one, and two T2D-linked TCF7L2 alleles were present in 48.1%, 43.9%, and 8.0% of the participants, respectively. Insulin sensitivity (as reflected by 1/fasting insulin [1/IF]) decreased with increasing BMI z score and was lower in Hispanics. Insulin secretion (as measured by 30-min C-peptide index) positively correlated with age and BMI z score. Oral disposition index was negatively correlated with age, BMI z score, and Hispanic ethnicity. None of the indices were associated with TCF7L2 SNPs. In multivariable analysis models with age, BMI z score, ethnicity, sex, and TCF7L2 alleles as independent variables, C-peptide index increased with age, while BMI z score was associated with higher insulin secretion (C-peptide index), lower insulin sensitivity (1/IF), and lower disposition index; there was no significant effect of TCF7L2 SNPs on any of these indices. When restricting the analyses to participants with a normal OGTT (n = 743; 70%), the results were similar.Conclusions: In nondiabetic autoantibody-positive individuals, TCF7L2 SNPs were not related to insulin sensitivity or secretion indices after accounting for BMI z score, age, sex, and ethnicity. [ABSTRACT FROM AUTHOR]

Objective: The metabolic phenotype of youth-onset type 2 diabetes (T2D) differs from that of adult-onset T2D, but little is known about genetic contributions. We aimed to evaluate the association between a T2D genetic risk score (GRS) and traits related to glucose-insulin homeostasis among healthy youth.Research Design and Methods: We used data from 356 youth (mean age 16.7 years; 50% female) in the Exploring Perinatal Outcomes Among Children (EPOCH) cohort to calculate a standardized weighted GRS based on 271 single nucleotide polymorphisms associated with T2D in adults. We used linear regression to assess associations of the GRS with log-transformed fasting glucose, 2-h glucose, HOMA of insulin resistance (HOMA-IR), oral disposition index, and insulinogenic index adjusted for age, sex, BMI z score, in utero exposure to maternal diabetes, and genetic principal components. We also evaluated effect modification by BMI z score, in utero exposure to maternal diabetes, and ethnicity.Results: Higher weighted GRS was associated with lower oral disposition index (β = -0.11; 95% CI -0.19, -0.02) and insulinogenic index (β = -0.08; 95% CI -0.17, -0.001), but not with fasting glucose (β = 0.01; 95% CI -0.01, 0.02), 2-h glucose (β = 0.03; 95% CI -0.0004, 0.06), or HOMA-IR (β = 0.02; 95% CI -0.04, 0.07). BMI z score and in utero exposure to maternal diabetes increased the effect of the GRS on glucose levels.Conclusions: Our results suggest that T2D genetic risk factors established in adults are relevant to glucose-insulin homeostasis in youth and that maintaining a healthy weight may be particularly important for youth with high genetic risk of T2D. [ABSTRACT FROM AUTHOR]

Objective: To compare effects of medications and laparoscopic gastric band surgery (LB) on α-cell function in dysglycemic youth and adults in the Restoring Insulin Secretion (RISE) Study protocols.Research Design and Methods: Glucagon was measured in three randomized, parallel, clinical studies: 1) 91 youth studied at baseline, after 12 months on metformin alone (MET) or glargine followed by metformin (G/M), and 3 months after treatment withdrawal; 2) 267 adults studied at the same time points and treated with MET, G/M, or liraglutide plus metformin (L+M) or given placebo (PLAC); and 3) 88 adults studied at baseline and after 12 and 24 months of LB or MET. Fasting glucagon, glucagon suppression by glucose, and acute glucagon response (AGR) to arginine were assessed during hyperglycemic clamps. Glucagon suppression was also measured during oral glucose tolerance tests (OGTTs).Results: No change in fasting glucagon, steady-state glucagon, or AGR was seen at 12 months following treatment with MET or G/M (in youth and adults) or PLAC (in adults). In contrast, L+M reduced these measures at 12 months (all P ≤ 0.005), which was maintained 3 months after treatment withdrawal (all P < 0.01). LB in adults also reduced fasting glucagon, steady-state glucagon, and AGR at 12 and 24 months (P < 0.05 for all, except AGR at 12 months [P = 0.098]). Similarly, glucagon suppression during OGTTs was greater with L+M and LB. Linear models demonstrated that treatment effects on glucagon with L+M and LB were largely associated with weight loss.Conclusions: Glucagon concentrations were reduced by L+M and LB in adults with dysglycemia, an effect principally attributable to weight loss in both interventions. [ABSTRACT FROM AUTHOR]

Objective: To determine whether β-cell hyperresponsiveness and insulin resistance in youth versus adults in the Restoring Insulin Secretion (RISE) Study are related to increased glucagon release.Research Design and Methods: In 66 youth and 350 adults with impaired glucose tolerance (IGT) or recently diagnosed type 2 diabetes (drug naive), we performed hyperglycemic clamps and oral glucose tolerance tests (OGTTs). From clamps we quantified insulin sensitivity (M/I), plasma fasting glucagon and C-peptide, steady-state glucagon and C-peptide at glucose of 11.1 mmol/L, and arginine-stimulated glucagon (acute glucagon response [AGR]) and C-peptide (ACPRmax) responses at glucose >25 mmol/L.Results: Mean ± SD fasting glucagon (7.63 ± 3.47 vs. 8.55 ± 4.47 pmol/L; P = 0.063) and steady-state glucagon (2.24 ± 1.46 vs. 2.49 ± 1.96 pmol/L, P = 0.234) were not different in youth and adults, respectively, while AGR was lower in youth (14.1 ± 5.2 vs. 16.8 ± 8.8 pmol/L, P = 0.001). Significant age-group differences in insulin sensitivity, fasting C-peptide, steady-state C-peptide, and ACPRmax were not related to glucagon. Fasting glucose and glucagon were positively correlated in adults (r = 0.133, P = 0.012) and negatively correlated in youth (r = -0.143, P = 0.251). In both age-groups, higher fasting glucagon was associated with higher fasting C-peptide (youth r = 0.209, P = 0.091; adults r = 0.335, P < 0.001) and lower insulin sensitivity (youth r = -0.228, P = 0.066; adults r = -0.324, P < 0.001). With comparable fasting glucagon, youth had greater C-peptide and lower insulin sensitivity. OGTT suppression of glucagon was greater in youth.Conclusions: Youth with IGT or recently diagnosed type 2 diabetes (drug naive) have hyperresponsive β-cells and lower insulin sensitivity, but their glucagon concentrations are not increased compared with those in adults. Thus, α-cell dysfunction does not appear to explain the difference in β-cell function and insulin sensitivity in youth versus adults. [ABSTRACT FROM AUTHOR]

Objective: This randomized controlled-feeding trial aimed to determine the impact of fried meat intake on the gut microbiota and fecal cometabolites and whether such impacts influenced host glucose homoeostasis, intestinal endotoxin levels, and systemic inflammation.Research Design and Methods: A total of 117 overweight adults were randomized into two groups. Fifty-nine participants were provided fried meat four times per week, and 58 participants were restricted from fried meat intake, while holding food group and nutrient compositions constant, for 4 weeks. The gut microbiota was analyzed by 16S rRNA sequencing. Glucose and insulin concentrations at 0, 30, 60, and 120 min of an oral glucose tolerance test, fecal microbiota-host cometabolite levels, and intestinal endotoxin and inflammation serum biomarker levels were measured. The area under the curve (AUC) for insulin, insulinogenic index (IGI), and muscle insulin resistance index (MIRI) were calculated.Results: The participants who consumed fried meat had lower IGI values than the control subjects, but they had higher MIRI and AUC values of insulin and lipopolysaccharide (LPS), TNF-α, IL-10, and IL-1β levels (P < 0.05). Fried meat intake lowered microbial community richness and decreased Lachnospiraceae and Flavonifractor abundances while increasing Dialister, Dorea, and Veillonella abundances (P FDR <0.05), provoking a significant shift in the fecal cometabolite profile, with lower 3-indolepropionic acid, valeric acid, and butyric acid concentrations and higher carnitine and methylglutaric acid concentrations (P FDR <0.05). Changes in these cometabolite levels were significantly associated with changes in IGI and MIRI values and LPS, FGF21, TNF-α, IL-1β, and IL-10 levels (P < 0.05).Conclusions: Fried meat intake impaired glucose homoeostasis and increased intestinal endotoxin and systemic inflammation levels by influencing the gut microbiota and microbial-host cometabolites. [ABSTRACT FROM AUTHOR]

Objective: Identifying metabolic factors associated with critical disease can help to improve management of patients hospitalized for coronavirus disease 2019 (COVID-19). High triglycerides and low HDL levels characterize the atherogenic dyslipidemia closely related to insulin resistance and diabetes. We examined associations of atherogenic dyslipidemia detected on admission with outcome of COVID-19 during hospitalization.Research Design and Methods: We retrospectively analyzed clinical reports of 118 consecutive patients hospitalized for COVID-19 in Rome, Italy, between March and May 2020. Clinical characteristics, inflammation markers, and glucose and lipid metabolism parameters at admission were collected. Critical disease was defined as in-hospital death or need for endotracheal intubation. Associations were tested using logistic regression analysis.Results: Patients with critical COVID-19 (n = 43) were significantly older than those with noncritical disease (n = 75) and presented higher levels of fasting glucose, triglycerides, C-reactive protein, interleukin-6, procalcitonin, and d-dimer (P < 0.01 for all), whereas HDL levels were lower (P = 0.003). Atherogenic dyslipidemia was more frequent in patients with critical COVID-19 (46 vs. 24%, P = 0.011), as well as diabetes (37 vs. 19%, P = 0.026), and significantly associated with death or intubation (odds ratio 2.53 [95% CI 1.16-6.32], P = 0.018). Triglycerides were significantly associated with selected inflammatory biomarkers (P < 0.05 for all) and poorer outcome of COVID-19 during hospitalization in both the overall population and the subgroup with atherogenic dyslipidemia.Conclusions: Atherogenic dyslipidemia detected on admission can be associated with critical in-hospital course of COVID-19. Further investigations are needed to elucidate the hypothetical role of insulin resistance and related lipid abnormalities in severe acute respiratory syndrome coronavirus 2 pathogenesis. Assessment of lipid profile should be encouraged in patients hospitalized for COVID-19. [ABSTRACT FROM AUTHOR]

Objective: Gestational diabetes mellitus (GDM) is associated with an increased risk of obesity and insulin resistance in offspring later in life, which might be explained by epigenetic changes in response to maternal hyperglycemic exposure.Research Design and Methods: We explored the association between GDM exposure and maternal blood and newborn cord blood methylation in 536 mother-offspring pairs from the prospective FinnGeDi cohort using Illumina MethylationEPIC 850K BeadChip arrays. We assessed two hypotheses. First, we tested for shared maternal and offspring epigenetic effects resulting from GDM exposure. Second, we tested whether GDM exposure and maternal methylation had an epigenetic effect on the offspring.Results: We did not find any epigenetic marks (differentially methylated CpG probes) with shared and consistent effects between mothers and offspring. After including maternal methylation in the model, we identified a single significant (false discovery rate 1.38 × 10-2) CpG at the cg22790973 probe (TFCP2) associated with GDM. We identified seven additional FDR-significant interactions of maternal methylation and GDM status, with the strongest association at the same cg22790973 probe (TFCP2), as well as cg03456133, cg24440941 (H3C6), cg20002843 (LOC127841), cg19107264, and cg11493553 located within the UBE3C gene and cg17065901 in FAM13A, both susceptibility genes for type 2 diabetes and BMI, and cg23355087 within the DLGAP2 gene, known to be involved in insulin resistance during pregnancy.Conclusions: Our study reveals the potential complexity of the epigenetic transmission between mothers with GDM and their offspring, likely determined by not only GDM exposure but also other factors indicated by maternal epigenetic status, such as maternal metabolic history. [ABSTRACT FROM AUTHOR]

ObjectiveWe examined the associations of symptoms of sleep-disordered breathing (SDB), which was defined as loud snoring, stopping breathing for a while during sleep, and daytime sleepiness, and insomnia with glucose metabolism and incident type 2 diabetes in older adults.Research design and methodsBetween 1989 and 1993, the Cardiovascular Health Study recruited 5,888 participants ≥65 years of age from four U.S. communities. Participants reported SDB and insomnia symptoms yearly through 1989-1994. In 1989-1990, participants underwent an oral glucose tolerance test, from which insulin secretion and insulin sensitivity were estimated. Fasting glucose levels were measured in 1989-1990 and again in 1992-1993, 1994-1995, 1996-1997, and 1998-1999, and medication use was ascertained yearly. We determined the cross-sectional associations of sleep symptoms with fasting glucose levels, 2-h glucose levels, insulin sensitivity, and insulin secretion using generalized estimated equations and linear regression models. We determined the associations of updated and averaged sleep symptoms with incident diabetes in Cox proportional hazards models. We adjusted for sociodemographics, lifestyle factors, and medical history.ResultsObserved apnea, snoring, and daytime sleepiness were associated with higher fasting glucose levels, higher 2-h glucose levels, lower insulin sensitivity, and higher insulin secretion. The risk of the development of type 2 diabetes was positively associated with observed apnea (hazard ratio [HR] 1.84 [95% CI 1.19-2.86]), snoring (HR 1.27 [95% CI 0.95-1.71]), and daytime sleepiness (HR 1.54 [95% CI 1.13-2.12]). In contrast, we did not find consistent associations between insomnia symptoms and glucose metabolism or incident type 2 diabetes.ConclusionsEasily collected symptoms of SDB are strongly associated with insulin resistance and the incidence of type 2 diabetes in older adults. Monitoring glucose metabolism in such patients may prove useful in identifying candidates for lifestyle or pharmacological therapy. Further studies are needed to determine whether insomnia symptoms affect the risk of diabetes in younger adults.

Objective: Insulin resistance (IR) may mediate heart failure (HF) development. We examined whether IR in people with newly diagnosed type 2 diabetes (T2D) increased their risk of a composite outcome of HF or death or of HF alone.Research Design and Methods: Insulin resistance (HOMA2-IR) values for UKPDS participants were derived from paired fasting plasma glucose (FPG) and insulin measures. Kaplan-Meier survival curves and multivariable survival models were used to evaluate associations between HOMA2-IR and HF/death or HF alone. We adjusted for potential confounders by including variables with univariate associations (P < 0.1) and by requiring a multivariable P < 0.05.Results: Of 5,102 UKPDS participants with newly diagnosed T2D, 4,344 had HOMA2-IR measurements. At enrollment, mean (SD) age was 52.5 (8.7) years, with HbA1c 7.2% (1.8%), and BMI 28.8 (5.5) kg/m2, and median (interquartile range) HOMA2-IR was 1.6 (1.1-2.2). HF/death occurred in 1,974 (45.4%) participants (235 first HF events, 1,739 deaths) over a median follow-up of 16.4 years. Multivariable independent associations with HF/death were older age and higher BMI, HOMA2-IR, FPG, waist-to-hip ratio, systolic blood pressure, LDL cholesterol, and heart rate as well as sex, race, smoking status, prior atrial fibrillation, and prior microalbuminuria. A doubling of HOMA2-IR was associated with a 5% greater risk of HF/death (relative risk [RR] 1.05 [95% CI 1.01-1.12], P = 0.0029) and a 14% greater risk of HF (RR 1.14, [95% CI 1.02-1.27], P = 0.017).Conclusions: Patients with newly diagnosed T2D and insulin resistance were more likely to develop HF or die than those more sensitive to insulin. [ABSTRACT FROM AUTHOR]

Objective: Stress, sleep, eating behavior, and physical activity are associated with weight change and insulin resistance (IR). The aim of this analysis was the assessment of the overall and sex-specific associations of psychobehavioral variables throughout the 3-year PREVIEW intervention using the homeostatic model assessment of IR (HOMA-IR), BMI, and length of time in the study.Research Design and Methods: Associations of psychobehavioral variables, including stress, mood, eating behavior, physical activity (PA), and sleep, with BMI, HOMA-IR, and time spent in the study were assessed in 2,184 participants with prediabetes and overweight/obesity (n = 706 men; n = 1,478 women) during a 3-year lifestyle intervention using linear mixed modeling and general linear modeling. The study was a randomized multicenter trial using a 2 × 2 diet-by-PA design.Results: Overall, cognitive restraint and PA increased during the intervention compared with baseline, whereas BMI, HOMA-IR, disinhibition, hunger, and sleepiness decreased (all P < 0.05). Cognitive restraint and PA were negatively, whereas disinhibition, hunger, stress, and total mood disturbance were positively, associated with both BMI and HOMA-IR. Sleep duration, low sleep quality, total mood disturbance, disinhibition, and hunger scores were positively associated with HOMA-IR for men only. Participants who dropped out at 6 months had higher stress and total mood disturbance scores at baseline and throughout their time spent in the study compared with study completers.Conclusions: Eating behavior and PA, control of stress, mood disturbance, and sleep characteristics were associated with BMI, HOMA-IR, and time spent in the study, with different effects in men and women during the PREVIEW lifestyle intervention study. [ABSTRACT FROM AUTHOR]

Objective: To determine the association of adipose tissue insulin resistance with longitudinal changes in biomarkers of adipose tissue function, circulating lipids, and dysglycemia.Research Design and Methods: Adults at risk for type 2 diabetes in the Prospective Metabolism and Islet Cell Evaluation (PROMISE) cohort had up to four assessments over 9 years (n = 468). Adipose tissue insulin resistance was determined using a novel validated index, Adipo-IR, calculated as the product of fasting insulin and nonesterified fatty acids measured at baseline. Fasting serum was used to measure biomarkers of adipose tissue function (adiponectin and soluble CD163 [sCD163]), circulating lipids (total cholesterol, HDL, LDL, triglyceride [TG]), and systemic inflammation (interleukin-6 [IL-6] and tumor necrosis factor-α [TNF-α]). Incident dysglycemia was defined as the onset of impaired fasting glucose, impaired glucose tolerance, or type 2 diabetes at follow-up. Generalized estimating equation (GEE) models were used to assess the relationship of Adipo-IR with longitudinal outcomes.Results: GEE analyses showed that elevated Adipo-IR was longitudinally associated with adipose tissue dysfunction (adiponectin -4.20% [95% CI -6.40 to -1.95]; sCD163 4.36% [1.73-7.06], HDL -3.87% [-5.15 to -2.57], TG 9.26% [5.01-13.69]). Adipo-IR was associated with increased risk of incident dysglycemia (odds ratio 1.59 [95% CI 1.09-2.31] per SD increase). Associations remained significant after adjustment for waist circumference and surrogate indices for insulin resistance. There were no significant longitudinal associations of Adipo-IR with IL-6, TNF-α, total cholesterol, or LDL.Conclusions: Our findings demonstrate that adipose tissue insulin resistance is prospectively associated with adipose tissue function, HDL, TG, and incident dysglycemia. [ABSTRACT FROM AUTHOR]

Objective: To evaluate changes in insulin sensitivity, hormone secretion, and hepatic steatosis immediately after caloric restriction, vertical sleeve gastrectomy (VSG), and Roux-en-Y gastric bypass (RYGB).Research Design and Methods: Obese subjects were assessed for 1) insulin sensitivity with hyperinsulinemic-euglycemic clamp with glucose tracer infusion, 2) adipokine concentrations with serum and subcutaneous adipose interstitial fluid sampling, and 3) hepatic fat content with MRI before and 7-10 days after VSG, RYGB, or supervised caloric restriction.Results: Each group exhibited an ∼5% total body weight loss, accompanied by similar improvements in hepatic glucose production and hepatic, skeletal muscle, and adipose tissue insulin sensitivity. Leptin concentrations in plasma and adipose interstitial fluid were equally decreased, and reductions in hepatic fat were similar.Conclusions: The improvements in insulin sensitivity and adipokine secretion observed early after bariatric surgery are replicated by equivalent caloric restriction and weight loss. [ABSTRACT FROM AUTHOR]

ObjectiveTo examine whether circulating total and high-molecular weight (HMW) adiponectin concentrations, measured before pregnancy, are associated with subsequent risk of gestational diabetes mellitus (GDM).Research design and methodsThis was a nested case-control study among women who participated in the Kaiser Permanente Northern California Multiphasic Health Check-up exam (1984-1996) with a serum sample obtained and who had a subsequent pregnancy (1984-2009). Eligible women were free of recognized diabetes. Case subjects were the 256 women who developed GDM. Two control subjects were selected for each case and matched for year of blood draw, age at exam, age at pregnancy, and number of intervening pregnancies.ResultsCompared with the highest quartile of adiponectin, the risk of GDM increased with decreasing quartile (odds ratio [OR] 1.5 [95% CI 0.7-2.9], 3.7 [1.9-7.2], and 5.2 [2.6-10.1]; P(trend)

Objective: Whereas insulin resistance is expressed as reduced glucose uptake in peripheral tissues, the relationship between insulin resistance and brain glucose metabolism remains controversial. Our aim was to examine the association of insulin resistance and brain glucose uptake (BGU) during a euglycemic hyperinsulinemic clamp in a large sample of study participants across a wide range of age and insulin sensitivity.Research Design and Methods: [18F]-fluorodeoxyglucose positron emission tomography (PET) data from 194 participants scanned under clamp conditions were compiled from a single-center cohort. BGU was quantified by the fractional uptake rate. We examined the association of age, sex, M value from the clamp, steady-state insulin and free fatty acid levels, C-reactive protein levels, HbA1c, and presence of type 2 diabetes with BGU using Bayesian hierarchical modeling.Results: Insulin sensitivity, indexed by the M value, was associated negatively with BGU in all brain regions, confirming that in insulin-resistant participants BGU was enhanced during euglycemic hyperinsulinemia. In addition, the presence of type 2 diabetes was associated with additional increase in BGU. On the contrary, age was negatively related to BGU. Steady-state insulin levels, C-reactive protein and free fatty acid levels, sex, and HbA1c were not associated with BGU.Conclusions: In this large cohort of participants of either sex across a wide range of age and insulin sensitivity, insulin sensitivity was the best predictor of BGU. [ABSTRACT FROM AUTHOR]

Objective: We examined the glucose response curves (biphasic [BPh], monophasic [MPh], incessant increase [IIn]) during an oral glucose tolerance test (OGTT) and their relationship to insulin sensitivity (IS) and β-cell function (βCF) in youth versus adults with impaired glucose tolerance or recently diagnosed type 2 diabetes.RESEARCH DESIGN AND METHODSThis was both a cross-sectional and a longitudinal evaluation of participants in the RISE study randomized to metformin alone for 12 months or glargine for 3 months followed by metformin for 9 months. At baseline/randomization, OGTTs (85 youth, 353 adults) were categorized as BPh, MPh, or IIn. The relationship of the glucose response curves to hyperglycemic clamp-measured IS and βCF at baseline and the change in glucose response curves 12 months after randomization were assessed.RESULTSAt randomization, the prevalence of the BPh curve was significantly higher in youth than adults (18.8% vs. 8.2%), with no differences in MPh or IIn. IS did not differ across glucose response curves in youth or adults. However, irrespective of curve type, youth had lower IS than adults (P < 0.05). βCF was lowest in IIn versus MPh and BPh in youth and adults (P < 0.05), yet compared with adults, youth had higher βCF in BPh and MPh (P < 0.005) but not IIn. At month 12, the change in glucose response curves did not differ between youth and adults, and there was no treatment effect.CONCLUSIONSDespite a twofold higher prevalence of the more favorable BPh curve in youth at randomization, RISE interventions did not result in beneficial changes in glucose response curves in youth compared with adults. Moreover, the typical β-cell hypersecretion in youth was not present in the IIn curve, emphasizing the severity of β-cell dysfunction in youth with this least favorable glucose response curve. [ABSTRACT FROM AUTHOR]

ObjectiveTo evaluate whether etiologic diabetes type is associated with the degree of albuminuria in children with diabetes. RESEARCH DESIGN AND METHODS SEARCH: is an observational, longitudinal study of children with diabetes. Youth with newly diagnosed diabetes were classified according to diabetes autoantibody (DAA) status and presence of insulin resistance. We defined insulin resistance as an insulin sensitivity score

ObjectiveWe aimed to identify factors that are independently associated with the metabolic clearance rate of insulin (MCRI) and to examine the association of MCRI with incident type 2 diabetes in nondiabetic Hispanics and African Americans.Research design and methodsWe investigated 1,116 participants in the Insulin Resistance Atherosclerosis Study (IRAS) Family Study with baseline examinations from 2000 to 2002 and follow-up examinations from 2005 to 2006. Insulin sensitivity (S(I)), acute insulin response (AIR), and MCRI were determined at baseline from frequently sampled intravenous glucose tolerance tests. MCRI was calculated as the ratio of the insulin dose over the incremental area under the curve of insulin. Incident diabetes was defined as fasting glucose ≥126 mg/dL or antidiabetic medication use by self-report.ResultsWe observed that S(I) and HDL cholesterol were independent positive correlates of MCRI, whereas fasting insulin, fasting glucose, subcutaneous adipose tissue, visceral adipose tissue, and AIR were independent negative correlates (all P < 0.05) at baseline. After 5 years of follow-up, 71 (6.4%) participants developed type 2 diabetes. Lower MCRI was associated with a higher risk of incident diabetes after adjusting for demographics, lifestyle factors, HDL cholesterol, indexes of obesity and adiposity, and insulin secretion (odds ratio 2.01 [95% CI 1.30-3.10], P = 0.0064, per one-SD decrease in loge-transformed MCRI).ConclusionsOur data showed that lower MCRI predicts the incidence of type 2 diabetes.

Objective: Both glucose and triglyceride production are increased in type 2 diabetes and nonalcoholic fatty liver disease (NAFLD). For decades, the leading hypothesis to explain these paradoxical observations has been selective hepatic insulin resistance wherein insulin drives de novo lipogenesis (DNL) while failing to suppress glucose production. Here, we aimed to test this hypothesis in humans.Research Design and Methods: We recruited obese subjects who met criteria for bariatric surgery with (n = 16) or without (n = 15) NAFLD and assessed 1) insulin-mediated regulation of hepatic and peripheral glucose metabolism using hyperinsulinemic-euglycemic clamps with [6,6-2H2]glucose, 2) fasting and carbohydrate-driven hepatic DNL using deuterated water (2H2O), and 3) hepatocellular insulin signaling in liver biopsy samples collected during bariatric surgery.Results: Compared with subjects without NAFLD, those with NAFLD demonstrated impaired insulin-mediated suppression of glucose production and attenuated-not increased-glucose-stimulated/high-insulin lipogenesis. Fructose-stimulated/low-insulin lipogenesis was intact. Hepatocellular insulin signaling, assessed for the first time in humans, exhibited a proximal block in insulin-resistant subjects: Signaling was attenuated from the level of the insulin receptor through both glucose and lipogenesis pathways. The carbohydrate-regulated lipogenic transcription factor ChREBP was increased in subjects with NAFLD.Conclusions: Acute increases in lipogenesis in humans with NAFLD are not explained by altered molecular regulation of lipogenesis through a paradoxical increase in lipogenic insulin action; rather, increases in lipogenic substrate availability may be the key. [ABSTRACT FROM AUTHOR]

Objective: The Treatment Options for type 2 Diabetes in Adolescents and Youth (TODAY) trial demonstrated that glycemic failure rates were significantly lower in youth randomized to metformin plus rosiglitazone treatment than in youth randomized to metformin alone or metformin plus intensive lifestyle intervention. At the end of the study, rosiglitazone was permanently discontinued, and routine diabetes care resumed. Herein, we report postintervention glycemic failure rates in TODAY participants over an additional 36 months of follow-up for the three original treatment arms and describe insulin sensitivity and β-cell function outcomes.Research Design and Methods: A total of 699 participants were randomized during TODAY, of whom 572 enrolled in the TODAY2 observational follow-up. Glycemic failure was defined as HbA1c ≥8% over a 6-month period, inability to wean from temporary insulin therapy within 3 months after acute metabolic decompensation during TODAY, or sustained HbA1c ≥8% over two consecutive visits during TODAY2. Oral glucose tolerance tests were conducted, and insulin sensitivity, insulinogenic index, and oral disposition index were calculated.Results: During the 36 months of TODAY2, glycemic failure rates did not differ among participants by original treatment group assignment. Insulin sensitivity and β-cell function deteriorated rapidly during the 36 months of TODAY2 routine diabetes care but did not differ by treatment group assignment.Conclusions: The added benefit of preventing glycemic failure by using rosiglitazone as a second agent in youth-onset type 2 diabetes did not persist after its discontinuation. More work is needed to address this rapid progression to avoid long-term diabetes complications. [ABSTRACT FROM AUTHOR]

Objective: To compare the effects of insulin sensitivity and β-cell function over time on HbA1c and durability of glycemic control in response to dual therapy., Research Design and Methods: GRADE participants were randomized to glimepiride (n = 1,254), liraglutide (n = 1,262), or sitagliptin (n = 1,268) added to baseline metformin and followed for mean ± SD 5.0 ± 1.3 years, with HbA1c assessed quarterly and oral glucose tolerance tests at baseline, 1, 3, and 5 years. We related time-varying insulin sensitivity (HOMA 2 of insulin sensitivity [HOMA2-%S]) and early (0-30 min) and total (0-120 min) C-peptide (CP) responses to changes in HbA1c and glycemic failure (primary outcome HbA1c ≥7% [53 mmol/mol] and secondary outcome HbA1c >7.5% [58 mmol/mol]) and examined differential treatment responses., Results: Higher HOMA2-%S was associated with greater initial HbA1c lowering (3 months) but not subsequent HbA1c rise. Greater CP responses were associated with a greater initial treatment response and slower subsequent HbA1c rise. Higher HOMA2-%S and CP responses were each associated with lower risk of primary and secondary outcomes. These associations differed by treatment. In the sitagliptin group, HOMA2-%S and CP responses had greater impact on initial HbA1c reduction (test of heterogeneity, P = 0.009 HOMA2-%S, P = 0.018 early CP, P = 0.001 total CP) and risk of primary outcome (P = 0.005 HOMA2-%S, P = 0.11 early CP, P = 0.025 total CP) but lesser impact on HbA1c rise (P = 0.175 HOMA2-%S, P = 0.006 early CP, P < 0.001 total CP) in comparisons with the glimepiride and liraglutide groups. There were no differential treatment effects on secondary outcome., Conclusions: Insulin sensitivity and β-cell function affected treatment outcomes irrespective of drug assignment, with greater impact in the sitagliptin group on initial (short-term) HbA1c response in comparison with the glimepiride and liraglutide groups., (© 2024 by the American Diabetes Association.)

Objective: To examine the effect of empagliflozin on liver fat content in individuals with and without type 2 diabetes (T2D) and the relationship between the decrease in liver fat and other metabolic actions of empagliflozin., Research Design and Methods: Thirty individuals with T2D and 27 without were randomly assigned to receive in double-blind fashion empagliflozin or matching placebo (2:1 ratio) for 12 weeks. Participants underwent 75-g oral glucose tolerance testing and measurement of liver fat content with MRS before therapy and at study end. Hepatic glucose production before the start of therapy was measured with 3-3H-glucose., Results: Empagliflozin caused an absolute reduction of 2.39% ± 0.79% in liver fat content compared with an increase of 0.91% ± 0.64% in participants receiving placebo (P < 0.007 with ANOVA). The decrease in liver fat was comparable in both individuals with diabetes and those without (2.75% ± 0.81% and 1.93% ± 0.78%, respectively; P = NS). The decrease in hepatic fat content caused by empagliflozin was strongly correlated with baseline liver fat content (r = -0.62; P < 0.001), decrease in body weight (r = 0.53; P < 0.001), and improvement in insulin sensitivity (r = -0.51; P < 0.001) but was not related to the decrease in fasting plasma glucose or HbA1c or the increase in hepatic glucose production., Conclusions: Empagliflozin is effective in reducing liver fat content in individuals with and without T2D. The decrease in liver fat content is independent of the decrease in plasma glucose concentration and is strongly related to the decrease in body weight and improvement in insulin sensitivity., (© 2024 by the American Diabetes Association.)

Decline in insulin sensitivity due to dysfunction of adipose tissue (AT) is one of the earliest pathogenic events in type 2 diabetes. We hypothesize that differential DNA methylation (DNAm) controls insulin sensitivity and obesity by modulating transcript expression in AT. Integrating AT DNAm profiles with transcript profile data measured in a cohort of 230 African Americans (AAs) from the African American Genetics of Metabolism and Expression cohort, we performed cis-expression quantitative trait methylation (cis-eQTM) analysis to identify epigenetic regulatory loci for glucometabolic trait-associated transcripts. We identified significantly associated cytosine-guanine dinucleotide regions for 82 transcripts (false discovery rate [FDR]-P < 0.05). The strongest eQTM locus was observed for the proopiomelanocortin (POMC; ρ = -0.632, P = 4.70 × 10-27) gene. Epigenome-wide association studies (EWAS) further identified 155, 46, and 168 cytosine-guanine dinucleotide regions associated (FDR-P < 0.05) with the Matsuda index, SI, and BMI, respectively. Intersection of EWAS, transcript level to trait association, and eQTM results, followed by causal inference test identified significant eQTM loci for 23 genes that were also associated with Matsuda index, SI, and/or BMI in EWAS. These associated genes include FERMT3, ITGAM, ITGAX, and POMC In summary, applying an integrative multiomics approach, our study provides evidence for DNAm-mediated regulation of gene expression at both previously identified and novel loci for many key AT transcripts influencing insulin resistance and obesity. [ABSTRACT FROM AUTHOR]

ObjectiveThe metabolic syndrome (MetS) is highly prevalent and confers an increased risk for diabetes and cardiovascular disease (CVD). While MetS is a proinflammatory state, there is a paucity of data on cellular inflammation in MetS. Toll-like receptors (TLRs) are classical pattern recognition receptors of the innate immune response.Research design and methodsThe aim of this study was to examine monocyte TLR2 and TLR4 in MetS patients without diabetes or CVD and control subjects since both of the receptors have been implicated in atherosclerosis and insulin resistance. Fasting blood was obtained for TLR expression and activity.ResultsCirculating levels of high-sensitivity C-reactive protein, interleukin (IL)-1β, IL-6, IL-8, and soluble tumor necrosis factor receptor 1 (sTNFR1) were significantly increased in MetS versus control subjects following adjustment for waist circumference. There was a significant increase in both TLR2 and TLR4 surface expression and mRNA on monocytes after adjustment for waist circumference. In addition to increased nuclear factor-κB nuclear binding, there was significantly increased release of IL-1β, IL-6, and IL-8 in MetS versus control subjects following priming of the monocytes with lipopolysaccharides. While both plasma free fatty acids and endotoxin were increased in MetS, they correlated significantly with TLR4 only.ConclusionsIn conclusion, we make the novel observation that both TLR2 and TLR4 expression and activity are increased in the monocytes of patients with MetS and could contribute to increased risk for diabetes and CVD.