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Background It is well known that a large number of patients with diabetes also have dyslipidemia, which significantly increases the risk of cardiovascular disease (CVD). This study aimed to evaluate the efficacy and safety of combination drugs consisting of metformin and atorvastatin, widely used as therapeutic agents for diabetes and dyslipidemia. Methods This randomized, double-blind, placebo-controlled, parallel-group and phase III multicenter study included adults with glycosylated hemoglobin (HbA1c) levels >7.0% and 100 and

ABSTRACT Aims/Introduction Several cross‐sectional studies have shown that delayed heart rate recovery (HRR) after exercise is associated with the development of metabolic syndrome (MetS). However, there has been a lack of comprehensively designed longitudinal studies. Therefore, our aim was to evaluate the longitudinal association of delayed HRR following a graded exercise treadmill test (GTX) with incident MetS. Materials and Methods This was a retrospective longitudinal cohort study of participants without MetS, diabetes, or cardiovascular diseases. The HRR was calculated as the peak heart rate minus the resting heart rate after a 1 min rest (HRR1), a 2 min rest (HRR2), and a 3 min rest (HRR3). Multivariate Cox proportional hazards analysis was performed to investigate the association between HRR and development of MetS. Results There were 676 (31.2%) incident cases of MetS identified during the follow‐up period (9,683 person‐years). The only statistically significant relationship was between HRR3 and the development of MetS. The hazard ratios (HRs) (95% confidence interval [CI]) of incident MetS comparing the first and second tertiles to the third tertile of HRR3 were 1.492 (1.146–1.943) and 1.277 (1.004–1.624) with P = 0.003 after adjustment for multiple risk factors. As a continuous variable, the HR (95% CI) of incident MetS associated with each one‐beat decrease in HRR3 was 1.015 (1.005–1.026) with P = 0.004 after full adjustments. An HRR3 value ≤45 beats per minute (bpm) was associated with a higher risk of incident MetS compared with values >45 bpm, with an HR (95% CI) of 1.304 (1.061–1.602) and P = 0.001. Conclusions The slow phase of HRR, particularly HRR3, might be more sensitive at predicting the risk of MetS.

Objective: The endocrine pancreatic β-cells play a pivotal role in maintaining whole-body glucose homeostasis and its dysregulation is a consistent feature in all forms of diabetes. However, knowledge of intracellular regulators that modulate β-cell function remains incomplete. We investigated the physiological role of ROCK1 in the regulation of insulin secretion and glucose homeostasis. Methods: Mice lacking ROCK1 in pancreatic β-cells (RIP-Cre; ROCK1loxP/loxP, β-ROCK1−/−) were studied. Glucose and insulin tolerance tests as well as glucose-stimulated insulin secretion (GSIS) were measured. An insulin secretion response to a direct glucose or pyruvate or pyruvate kinase (PK) activator stimulation in isolated islets from β-ROCK1−/− mice or β-cell lines with knockdown of ROCK1 was also evaluated. A proximity ligation assay was performed to determine the physical interactions between PK and ROCK1. Results: Mice with a deficiency of ROCK1 in pancreatic β-cells exhibited significantly increased blood glucose levels and reduced serum insulin without changes in body weight. Interestingly, β-ROCK1−/− mice displayed a progressive impairment of glucose tolerance while maintaining insulin sensitivity mostly due to impaired GSIS. Consistently, GSIS markedly decreased in ROCK1-deficient islets and ROCK1 knockdown INS-1 cells. Concurrently, ROCK1 blockade led to a significant decrease in intracellular calcium and ATP levels and oxygen consumption rates in isolated islets and INS-1 cells. Treatment of ROCK1-deficient islets or ROCK1 knockdown β-cells either with pyruvate or a PK activator rescued the impaired GSIS. Mechanistically, we observed that glucose stimulation in β-cells greatly enhanced ROCK1 binding to PK. Conclusions: Our findings demonstrate that β-cell ROCK1 is essential for glucose-stimulated insulin secretion and for glucose homeostasis and that ROCK1 acts as an upstream regulator of glycolytic pyruvate kinase signaling.

Background Carnitine orotate complex (Godex) has been shown to decrease glycated hemoglobin levels and improve steatosis in patients with type 2 diabetes mellitus with non-alcoholic fatty liver disease. However, the mechanisms of Godex in glucose metabolism remain unclear. Methods Male C57BL/6J mice were divided into four groups: normal-fat diet, high-fat diet, a high-fat diet supplemented with intraperitoneal injection of (500 mg or 2,000 mg/kg/day) Godex for 8 weeks. Computed tomography, indirect calorimetry, and histological analyses including electron microscopy of the liver were performed, and biochemical profiles and oral glucose tolerance test and insulin tolerance test were undertaken. Expressions of genes in the lipid and glucose metabolism, activities of oxidative phosphorylation enzymes, carnitine acetyltransferase, pyruvate dehydrogenase, and acetyl-coenzyme A (CoA)/CoA ratio were evaluated. Results Godex improved insulin sensitivity and significantly decreased fasting plasma glucose, homeostatic model assessment for insulin resistance, steatosis, and gluconeogenesis, with a marked increase in fatty acid oxidation as well as better use of glucose in high-fat diet-fed mice. It preserved mitochondrial function and ultrastructure, restored oxidative phosphorylation enzyme activities, decreased acetyl-CoA/CoA ratio, and increased carnitine acetyltransferase content and pyruvate dehydrogenase activity. Carnitine acetyltransferase knockdown partially reversed the effects of Godex in liver and in vitro. Conclusion Godex improved insulin resistance and steatosis by regulating carnitine acetyltransferase in liver in high-fat diet-fed mice.

Background Cardiovascular autonomic neuropathy (CAN) is a common microvascular complication of diabetes and related to albuminuria in diabetic nephropathy (DN). Urinary N-acetyl-β-D-glucosaminidase (uNAG) is a renal tubular injury marker which has been reported as an early marker of DN even in patients with normoalbuminuria. This study evaluated whether uNAG is associated with the presence and severity of CAN in patients with type 1 diabetes mellitus (T1DM) without nephropathy. Methods This cross-sectional study comprised 247 subjects with T1DM without chronic kidney disease and albuminuria who had results for both uNAG and autonomic function tests within 3 months. The presence of CAN was assessed by age-dependent reference values for four autonomic function tests. Total CAN score was assessed as the sum of the partial points of five cardiovascular reflex tests and was used to estimatethe severity of CAN. The correlations between uNAG and heart rate variability (HRV) parameters were analyzed. Results The association between log-uNAG and presence of CAN was significant in a multivariate logistic regression model (adjusted odds ratio, 2.39; 95% confidence interval [CI], 1.08 to 5.28; P=0.031). Total CAN score was positively associated with loguNAG (β=0.261, P=0.026) in the multivariate linear regression model. Log-uNAG was inversely correlated with frequency-domain and time-domain indices of HRV. Conclusion This study verified the association of uNAG with presence and severity of CAN and changes in HRV in T1DM patients without nephropathy. The potential role of uNAG should be further assessed for high-risk patients for CAN in T1DM patients without nephropathy.

Abstract Aims/Introduction Using an investigational diet plan based on the Mediterranean diet and the Dietary Approaches to Stop Hypertension diet comprised of substitute ingredients that mimic the average East Asian diet, this study assessed the glycemic benefits in comparison with a food exchange system‐based diet in established type 2 diabetes patients. Materials and Methods This was a 12‐week, open‐label randomized clinical trial carried out among 60 Korean adults with type 2 diabetes having a median body mass index of 23.5 kg/m2. Glycemic benefits in the investigational diet (group A) were compared with those obtained with a food exchange system‐based diet, either in the form of ready meals provided to participants (group B) or not (group C). The primary end‐point was changes in glycated hemoglobin from baseline to week 12. Results Changes in glycated hemoglobin (%) from baseline to week 12 were −0.97 ± 0.97 in group A (vs group B, P = 0.085 in the full analysis set, and P = 0.028 in the per‐protocol set; vs group C, P = 0.030 in the full analysis set and P = 0.020 in the per‐protocol set), −0.51 ± 0.65 in group B (vs group C, P > 0.05 in the full analysis set and the per‐protocol set), and −0.36 ± 0.74 in group C. Decreases from baseline in body mass index, waist circumference and blood pressure were greater in group A than in group C. Conclusion With the provision of ready meals, the glycemic benefits of the investigational diet plan were demonstrable over a self‐prepared food exchange system‐based diet in Korean adults with established type 2 diabetes.

Background Type 2 diabetes and cardiovascular disease (CVD) are the most important sequelae of obesity and the leading cause of death. We evaluated the association between body mass index (BMI) and the risk of incident type 2 diabetes, CVD, and all-cause mortality in a prospective study of a Korean population. Methods The shapes of the associations were modeled by restricted cubic splines regression analysis. After categorizing all subjects (n=8,900) into octiles based on their BMI levels, we estimated the hazard ratio (HR) for the association of categorized BMI levels with the risk of incident CVD and type 2 diabetes using a Cox’s proportional hazard analysis. Results The mean age of participants was 52 years and 48% were men. Of the subjects at baseline, 39.0% of men and 45.6% of women were classified as obese (BMI ≥25 kg/m2). Over a mean follow-up of 8.1 years, CVD events occurred in 509 participants; 436 died; and 1,258 subjects developed type 2 diabetes. The increased risk of incident diabetes began to be significant at BMI 23 to 24 kg/m2 in both sexes (HR, 1.8). For CVD events, the risk began to increase significantly at BMI 26 to 28 kg/m2 (HR, 1.6). We found a reverse J-shaped relationship between BMI and all-cause mortality, with an increased risk among individuals with BMI values in lower range (BMI

BackgroundTo investigate the performance of the 2013 American College of Cardiology/American Heart Association Pooled Cohort Equations (PCE) in a large, prospective, community-based cohort in Korea and to compare it with that of the Framingham Global Cardiovascular Disease Risk Score (FRS-CVD) and the Korean Risk Prediction Model (KRPM).MethodsIn the Korean Genome and Epidemiology Study (KOGES)-Ansan and Ansung study, we evaluated calibration and discrimination of the PCE for non-Hispanic whites (PCE-WH) and for African Americans (PCE-AA) and compared their predictive abilities with the FRS-CVD and the KRPM.ResultsThe present study included 7,932 individuals (3,778 men and 4,154 women). The PCE-WH and PCE-AA moderately overestimated the risk of atherosclerotic cardiovascular disease (ASCVD) for men (6% and 13%, respectively) but underestimated the risk for women (−49% and −25%, respectively). The FRS-CVD overestimated ASCVD risk for men (91%) but provided a good risk prediction for women (3%). The KRPM underestimated ASCVD risk for men (−31%) and women (−31%). All the risk prediction models showed good discrimination in both men (C-statistic 0.730 to 0.735) and women (C-statistic 0.726 to 0.732). Recalibration of the PCE using data from the KOGES-Ansan and Ansung study substantially improved the predictive accuracy in men.ConclusionIn the KOGES-Ansan and Ansung study, the PCE overestimated ASCVD risk for men and underestimated the risk for women. The PCE-WH and the FRS-CVD provided an accurate prediction of ASCVD in men and women, respectively.

BackgroundCardiovascular risk remains increased despite optimal low density lipoprotein cholesterol (LDL-C) level induced by intensive statin therapy. Therefore, recent guidelines recommend non-high density lipoprotein cholesterol (non-HDL-C) as a secondary target for preventing cardiovascular events. The aim of this study was to assess the efficacy and tolerability of omega-3 fatty acids (OM3-FAs) in combination with atorvastatin compared to atorvastatin alone in patients with mixed dyslipidemia.MethodsThis randomized, double-blind, placebo-controlled, parallel-group, and phase III multicenter study included adults with fasting triglyceride (TG) levels ≥200 and

BackgroundWe aimed to describe the outcome of a computerized intravenous insulin infusion (CII) protocol integrated to the electronic health record (EHR) system and to improve the CII protocol in silico using the EHR-based predictors of the outcome.MethodsClinical outcomes of the patients who underwent the CII protocol between July 2016 and February 2017 and their matched controls were evaluated. In the CII protocol group (n=91), multivariable binary logistic regression analysis models were used to determine the independent associates with a delayed response (taking ≥6.0 hours for entering a glucose range of 70 to 180 mg/dL). The CII protocol was adjusted in silico according to the EHR-based parameters obtained in the first 3 hours of CII.ResultsUse of the CII protocol was associated with fewer subjects with hypoglycemia alert values (P=0.003), earlier (P=0.002), and more stable (P=0.017) achievement of a glucose range of 70 to 180 mg/dL. Initial glucose level (P=0.001), change in glucose during the first 2 hours (P=0.026), and change in insulin infusion rate during the first 3 hours (P=0.029) were independently associated with delayed responses. Increasing the insulin infusion rate temporarily according to these parameters in silico significantly reduced delayed responses (P

Introduction The concept of glucolipotoxicity refers to the combined, deleterious effects of elevated glucose and/or fatty acid levels.Research design and methods To investigate the effects of chronic glucolipotoxicity on glucagon-like peptide-1-(7-36) amide (GLP-1) secretion, we generated glucolipotoxic conditions in human NCI-H716 enteroendocrine cells using either 5 or 25 mM glucose with or without 500 µM palmitate for 72 hours. For in vivo study, we have established a chronic nutrient infusion model in the rat. Serial blood samples were collected for 2 hours after the consumption of a mixed meal to evaluate insulin sensitivity and β-cell function.Results Chronic glucolipotoxic conditions decreased GLP-1 secretion and the expressions of pCREB, pGSK3β, β-catenin, and TCF7L2 in NCI-H716 cells. Glucolipotoxicity conditions reduced glucose transporter expression, glucose uptake, and nicotinamide-adenine dinucleotide phosphate (NADPH) levels in L-cells, and increased triglyceride accumulation. In contrast, PPARα and ATP levels were reduced, which correlated well with decreased levels of SUR1 and Kir6.2, cAMP contents and expressions of pCAMK2, EPAC and PKA. We also observed an increase in reactive oxygen species production, UCP2 expression and Complex I activity. Simultaneous treatment with insulin restored the GLP-1 secretion. Glucolipotoxic conditions decreased insulin secretion in a time-dependent manner in INS-1 cells, which was recovered with exendin-4 cotreatment. Glucose and SMOFlipid infusion for 6 hours decreased GLP-1 secretion and proglucagon mRNA levels as well as impaired the glucose tolerance, insulin and C-peptide secretion in rats.Conclusion These results provide evidence for the first time that glucolipotoxicity could affect GLP-1 secretion through changes in glucose and lipid metabolism, gene expressions, and proglucagon biosynthesis and suggest the interrelationship between glucolipotoxicities of L-cells and β-cells which develops earlier than that of L-cells.

BackgroundIt has not been determined whether changes in serum uric acid (SUA) level are associated with incident metabolic syndrome (MetS). The aim of the current study was to investigate the relationship between changes in SUA level and development of MetS in a large number of subjects.MethodsIn total, 13,057 subjects participating in a medical health check-up program without a diagnosis of MetS at baseline were enrolled. Cox proportional hazards models were used to test the independent association of percent changes in SUA level with development of MetS.ResultsAfter adjustment for age, systolic blood pressure, body mass index, fat-free mass (%), estimated glomerular filtration rate, smoking status, fasting glucose, triglyceride, low density lipoprotein cholesterol, high density lipoprotein cholesterol, and baseline SUA levels, the hazard ratios (HRs) (95% confidence intervals [CIs]) for incident MetS in the second, third, and fourth quartiles compared to the first quartile of percent change in SUA level were 1.055 (0.936 to 1.190), 0.927 (0.818 to 1.050), and 0.807 (0.707 to 0.922) in male (P for trend

BackgroundMetformin, sulfonylurea, and dietary fiber are known to affect gut microbiota in patients with type 2 diabetes mellitus (T2DM). This open and single-arm pilot trial investigated the effects of the additional use of fiber on glycemic parameters, insulin, incretins, and microbiota in patients with T2DM who had been treated with metformin and sulfonylurea.MethodsParticipants took fiber for 4 weeks and stopped for the next 4 weeks. Glycemic parameters, insulin, incretins during mixed-meal tolerance test (MMTT), lipopolysaccharide (LPS) level, and fecal microbiota were analyzed at weeks 0, 4, and 8. The first tertile of difference in glucose area under the curve during MMTT between weeks 0 and 4 was defined as ‘responders’ and the third as ‘nonresponders,’ respectively.ResultsIn all 10 participants, the peak incretin levels during MMTT were higher and LPS were lower at week 4 as compared with at baseline. While the insulin sensitivity of the ‘responders’ increased at week 4, that of the ‘nonresponders’ showed opposite results. However, the results were not statistically significant. In all participants, metabolically unfavorable microbiota decreased at week 4 and were restored at week 8. At baseline, metabolically hostile bacteria were more abundant in the ‘nonresponders.’ In ‘responders,’ Roseburia intestinalis increased at week 4.ConclusionWhile dietary fiber did not induce additional changes in glycemic parameters, it showed a trend of improvement in insulin sensitivity in ‘responders.’ Even if patients are already receiving diabetes treatment, the additional administration of fiber can lead to additional benefits in the treatment of diabetes.

Abstract Aims/Introduction We investigated the safety and tolerability of empagliflozin (EMPA) in East Asian patients with type 2 diabetes. Materials and Methods Data were pooled from participants with type 2 diabetes evenly randomized to a placebo, EMPA 10 mg or EMPA 25 mg in 15 phase I–III trials. Adverse events (AEs) were analyzed in the subgroup of trial participants from East Asian countries/regions. Results In total, 709, 724 and 708 East Asian trial participants with type 2 diabetes received a placebo, EMPA 10 mg and EMPA 25 mg, respectively; total exposure was 953, 1,072, and 1,033 patient‐years in these groups, respectively. The EMPA and placebo groups had similar incidences of severe AEs, serious AEs and AEs leading to discontinuation. Incidences of hypoglycemia differed according to anti‐diabetes medication used at baseline. Higher rates of events consistent with genital infection were observed with EMPA (EMPA 1.5–1.7/100, placebo 0.2/100 patient‐years). Rates of AEs consistent with volume depletion were comparable among treatment groups (0.8–1.4/100 patient‐years), but in trial participants aged ≥65 years, the rate was greater with EMPA 25 mg (EMPA 25 mg 3.5/100, placebo 2.0/100 patient‐years). Incidences of events consistent with urinary tract infection, thromboembolic events, renal events, hepatic AEs, diabetic ketoacidosis, fractures and lower limb amputation were similar between EMPA and the placebo. Conclusions In the present pooled analysis, EMPA was well tolerated in East Asian type 2 diabetes patients based on >2,100 patient‐years’ exposure, consistent with results from the overall analysis population.

BackgroundThis report presents the recent prevalence and comorbidities related to diabetes in Korea by analyzing the nationally representative data.MethodsUsing data from the Korea National Health and Nutrition Examination Survey for 2013 to 2014, the percentages and the total number of subjects over the age of 30 years with diabetes and prediabetes were estimated and applied to the National Population Census in 2014. Diagnosis of diabetes was based on fasting plasma glucose (≥126 mg/dL), current taking of antidiabetic medication, history of previous diabetes, or glycosylated hemoglobin (HbA1c) ≥6.5%. Impaired fasting glucose (IFG) was defined by fasting plasma glucose in the range of 100 to 125 mg/dL among those without diabetes.ResultsAbout 4.8 million (13.7%) Korean adults (≥30 years old) had diabetes, and about 8.3 million (24.8%) Korean adults had IFG. However, 29.3% of the subjects with diabetes are not aware of their condition. Of the subjects with diabetes, 48.6% and 54.7% were obese and hypertensive, respectively, and 31.6% had hypercholesterolemia. Although most subjects with diabetes (89.1%) were under medical treatment, and mostly being treated with oral hypoglycemic agents (80.2%), 10.8% have remained untreated. With respect to overall glycemic control, 43.5% reached the target of HbA1c

Abstract Background Skeletal muscle mass was negatively associated with metabolic syndrome prevalence in previous cross-sectional studies. The aim of this study was to investigate the impact of baseline skeletal muscle mass and changes in skeletal muscle mass over time on the development of metabolic syndrome in a large population-based 7-year cohort study. Methods A total of 14,830 and 11,639 individuals who underwent health examinations at the Health Promotion Center at Samsung Medical Center, Seoul, Korea were included in the analyses of baseline skeletal muscle mass and those changes from baseline over 1 year, respectively. Skeletal muscle mass was estimated by bioelectrical impedance analysis and was presented as a skeletal muscle mass index (SMI), a body weight-adjusted appendicular skeletal muscle mass value. Using Cox regression models, hazard ratio for developing metabolic syndrome associated with SMI values at baseline or changes of SMI over a year was analyzed. Results During 7 years of follow-up, 20.1% of subjects developed metabolic syndrome. Compared to the lowest sex-specific SMI tertile at baseline, the highest sex-specific SMI tertile showed a significant inverse association with metabolic syndrome risk (adjusted hazard ratio [AHR] = 0.61, 95% confidence interval [CI] 0.54–0.68). Furthermore, compared with SMI changes 1% changes in SMI over 1 year after additionally adjusting for baseline SMI and glycometabolic parameters. Conclusions An increase in relative skeletal muscle mass over time has a potential preventive effect on developing metabolic syndrome, independently of baseline skeletal muscle mass and glycometabolic parameters.

Abstract Background We investigated whether glycated albumin (GA) and its variability are associated with cardiovascular autonomic neuropathy (CAN) and further compared their associations with glycated hemoglobin (HbA1c). Methods This retrospective longitudinal study included 498 type 2 diabetic patients without CAN. CAN was defined as at least two abnormal results in parasympathetic tests or presence of orthostatic hypotension. The mean, standard deviation (SD), and coefficient of variance (CV) were calculated from consecutively measured GA (median 7 times) and HbA1c levels (median 8 times) over 2 years. Logistic regression analysis was used to compare the associations between CAN and GA- or HbA1c-related parameters. Receiver operating characteristic (ROC) curve analysis was used to compare the predictive power for CAN between GA- and HbA1c-related parameters. Results A total of 53 subjects (10.6%) developed CAN over 2 years. The mean, SD, and CV of GA or HbA1c were significantly higher in subjects with CAN. Higher mean GA and GA variability were associated with the risk of developing CAN, independent of conventional risk factors and HbA1c. In ROC curve analysis, the SD and CV of GA showed higher predictive value for CAN compared to the SD and CV of HbA1c, whereas the predictive value of mean GA did not differ from that of mean HbA1c. The mean, SD, and CV of GA showed additive predictive power to detect CAN development along with mean HbA1c. Conclusions Higher serum GA and its variability are significantly associated with the risk of developing CAN. Serum GA might be a useful indicator for diabetic complications and can enhance HbA1c’s modest clinical prediction for CAN.

Abstract Background A Personal Health Record (PHR) is an online application that allows patients to access, manage, and share their health data. PHRs not only enhance shared decision making with healthcare providers, but also enable remote monitoring and at-home-collection of detailed data. The benefits of PHRs can be maximized in insulin dose adjustment for patients starting or intensifying insulin regimens, as frequent self-monitoring of glucose, self-adjustment of insulin dose, and precise at-home data collection during the visit-to-visit period are important for glycemic control. The aim of this study is to examine the efficacy and safety of insulin dose adjustment based on a smartphone PHR application in patients with diabetes mellitus (DM) and to confirm the validity and stability of an information and communication technology (ICT)-based centralized clinical trial monitoring system. Methods This is a 24-week, open-label, randomized, multi-center trial. There are three follow-up measures: baseline, post-intervention at week 12, and at week 24. Subjects diagnosed with type 1 DM, type 2 DM, and/or post-transplant DM who initiate basal insulin or intensify their insulin regimen to a basal-bolus regimen are included. After education on insulin dose titration and prevention for hypoglycemia and a 1-week acclimation period, subjects are randomized in a 1:1 ratio to either an ICT-based intervention group or a conventional intervention group. Subjects in the conventional intervention group will save and send their health information to the server via a PHR application, whereas those in ICT-based intervention group will receive additional algorithm-based feedback messages. The health information includes level of blood glucose, insulin dose, details on hypoglycemia, food diary, and step count. The primary outcome will be the proportion of patients who reach an optimal insulin dose within 12 weeks of study enrollment, without severe hypoglycemia or unscheduled clinic visits. Discussion This clinical trial will reveal whether insulin dose adjustment based on a smartphone PHR application can facilitate the optimization of insulin doses in patients with DM. In addition, the process evaluation will provide information about the validity and stability of the ICT-based centralized clinical trial monitoring system in this research field. Trial registration Clinicaltrials.gov NCT 03112343 . Registered on 12 April 2017.

BackgroundDespite the established benefits of diabetes camps for the continuing education of children with type 1 diabetes mellitus, little is known about the long-term metabolic benefits of diabetes camps for middle-aged and elderly people with type 2 diabetes mellitus (T2DM), especially in terms of glycosylated hemoglobin (HbA1c) variability.MethodsThe 1-year mean and variability of HbA1c before and after the diabetes camp was compared between the participants of the diabetes camp (n=57; median age 65 years [range, 50 to 86 years]; median diabetes duration 14 years [range, 1 to 48 years]). Additional case-control analysis compared the metabolic outcomes of the participants of the diabetes camp and their propensity score-matched controls who underwent conventional diabetes education (n=93).ResultsThe levels of HbA1c during the first year after the diabetes camp were comparable to those of the matched controls (P=0.341). In an analysis of all participants of the diabetes camp, the 1-year mean±standard deviation (SD) of HbA1c decreased (P=0.010 and P=0.041) after the diabetes camp, whereas the adjusted SD and coefficient of variance (CV) of HbA1c did not decrease. The adjusted SD and CV significantly decreased after the diabetes camp in participants whose 1-year mean HbA1c was ≥6.5% before the diabetes camp (n=40) and those with a duration of diabetes less than 15 years (n=32).ConclusionThe 1-year mean and SD of HbA1c decreased after the diabetes camp, with significant reduction in the adjusted SD and CV in those with higher baseline HbA1c and a shorter duration of diabetes.

BackgroundAn association between serum calcium level and risk of metabolic syndrome (MetS) has been suggested in cross-sectional studies. This study aimed to evaluate the association between baseline serum calcium level and risk of incident MetS in a longitudinal study.MethodsWe conducted a retrospective longitudinal study of 12,706 participants without MetS who participated in a health screening program, had normal range serum calcium level at baseline (mean age, 51 years), and were followed up for 4.3 years (18,925 person-years). The risk of developing MetS was analyzed according to the baseline serum calcium levels.ResultsA total of 3,448 incident cases (27.1%) of MetS developed during the follow-up period. The hazard ratio (HR) for incident MetS did not increase with increasing tertile of serum calcium level in an age- and sex-matched model (P for trend=0.915). The HRs (95% confidence interval [CI]) for incident MetS comparing the second and the third tertiles to the first tertile of baseline serum calcium level were 0.91 (95% CI, 0.84 to 0.99) and 0.85 (95% CI, 0.78 to 0.92) in a fully adjusted model, respectively (P for trend=0.001). A decreased risk of incident MetS in higher tertiles of serum calcium level was observed in subjects with central obesity and/or a metabolically unhealthy state at baseline.ConclusionThere was no positive correlation between baseline serum calcium levels and incident risk of MetS in this longitudinal study. There was an association between higher serum calcium levels and decreased incident MetS in individuals with central obesity or two components of MetS at baseline.

BackgroundThis is a subgroup analysis of Korean patients from a phase 3 clinical trial investigating the efficacy and safety of ipragliflozin in patients with type 2 diabetes mellitus inadequately controlled with metformin.MethodsThis multicenter, placebo-controlled, double-blind, parallel-group study was carried out between November 2011 and January 2013. Patients entered a 2-week placebo pretreatment period, followed by a 24-week treatment period with either ipragliflozin (50 mg/day) or placebo, while continuing metformin. Efficacy outcomes (glycosylated hemoglobin [HbA1c], fasting plasma glucose [FPG], and body weight) and safety outcomes (treatment-emergent adverse events [TEAEs]) were measured and compared between the two treatment groups for patients enrolled in all 18 study sites in Korea.ResultsEighty-two Korean patients received ipragliflozin (n=43) or placebo (n=39) during the study period. Mean changes in HbA1c levels from baseline to the end of treatment were –0.97% in the ipragliflozin group and –0.31% in the placebo group, with an adjusted between-group difference of –0.60% (P

Abstract After publication of the original article [1] it was noted that both the figures and captions and relating to Figs. 1 and 2 had been interchanged.

BackgroundIncretin hormone levels as a predictor of type 2 diabetes mellitus have not been fully investigated. Therefore, we measured incretin hormone levels to examine the relationship between circulating incretin hormones, diabetes, and future diabetes development in this study.MethodsA nested case-control study was conducted in a Korean cohort. The study included the following two groups: the control group (n=149), the incident diabetes group (n=65). Fasting total glucagon-like peptide-1 (GLP-1) and total glucose-dependent insulinotropic peptide (GIP) levels were measured and compared between these groups.ResultsFasting total GIP levels were higher in the incident diabetes group than in the control group (32.64±22.68 pmol/L vs. 25.54±18.37 pmol/L, P=0.034). There was no statistically significant difference in fasting total GLP-1 levels between groups (1.14±1.43 pmol/L vs. 1.39±2.13 pmol/L, P=0.199). In multivariate analysis, fasting total GIP levels were associated with an increased risk of diabetes (odds ratio, 1.005; P=0.012) independent of other risk factors.ConclusionFasting total GIP levels may be a risk factor for the development of type 2 diabetes mellitus. This association persisted even after adjusting for other metabolic parameters such as elevated fasting glucose, hemoglobin A1c, and obesity in the pre-diabetic period.

We tested the hypothesis that higher levels of bilirubin, a bile pigment with antioxidant properties, are associated with a decreased risk of cardiovascular disease (CVD). This study analyzed data from the Korean Health and Genome Study to examine the association between serum total bilirubin (TB) on CVD and CVD death. Serum TB was measured in a total of 8,844 subjects (4,196 males and 4,648 females) and evaluated for the development of new onset CVD from 2001 to 2012 (mean 8.1 years of follow-up). During the follow-up period, 689 cases of incident CVD (7.8%) were identified, and the prevalence of metabolic syndrome (MetS) at baseline was 26.1%. The prevalence of MetS decreased across bilirubin tertile categories. In addition to MetS itself, individual components of MetS significantly decreased with increased bilirubin tertiles. Moreover, the incidence of CVD decreased across bilirubin tertile categories. The hazard ratios (HRs) for developing coronary heart disease (CHD, HR 0.769, 95% CI 0.655-1.000) and CVD death (HR 0.513, 95% CI 0.267-0.985) was significantly lower in the highest tertile group (> 0.63 mg/dL) in comparison to the lowest tertile group (< 0.44 mg/dL) after adjusting for all confounding variables. In the present longitudinal study, a significant negative relationship was demonstrated between baseline bilirubin levels and incident CHD and CVD death.

BackgroundThe aim of this study was to investigate whether adjusting diabetic treatment regimens according to the information obtained from a continuous glucose monitoring system (CGMS) might lead to improved glycemic control in patients with type 2 diabetes.MethodsWe reviewed the medical charts of 172 patients who used the CGMS for 1 year starting in December 2008 and the records of 1,500 patients who visited their regular outpatient clinics during December 2008. Of these patients, a total of 65 CGMS patients and 301 regular outpatients (control group) were enrolled in the study after propensity score matching. There were no differences in baseline glycated hemoglobin (HbA1c), age, and duration of diabetes between the CGMS and the control groups after propensity score matching. The changes in the HbA1c levels from baseline to 6 months were calculated.ResultsThe CGMS group showed a significant improvement in the HbA1c level compared to the control group at 3 months (7.9%±1.6% vs. 7.4%±1.2%, P=0.001) and at 6 months (7.4%±1.2% vs. 7.9%±1.6%, P=0.010). There were significant differences in the treatment modality changes between the CGMS group and the control group.ConclusionUsing a 3-day CGMS was advantageous for improving glucose control in patients with type 2 diabetes and may help these patients to optimize glycemic control in clinical practice.

BackgroundThe aim of this study was to assess the clinical differences between acromegalic patients with microadenoma and patients with macroadenoma, and to evaluate the predictive value of growth hormone (GH) levels for early detection of macroadenoma.MethodsWe performed a retrospective analysis of 215 patients diagnosed with a GH-secreting pituitary adenoma. The patients were divided into two groups: the microadenoma group and the macroadenoma group, and the clinical parameters were compared between these two groups. The most sensitive and specific GH values for predicting macroadenoma were selected using receiver operating characteristic (ROC) curves.ResultsCompared with the microadenoma group, the macroadenoma group had a significantly younger age, higher body mass index, higher prevalence of hyperprolactinemia and hypogonadism, and a lower proportion of positive suppression to octreotide. However, there were no significant differences in the gender or in the prevalence of diabetes between the two groups. The tumor diameter was positively correlated with all GH values during the oral glucose tolerance test (OGTT). All GH values were significantly higher in the macroadenoma group than the microadenoma group. Cut-off values for GH levels at 0, 30, 60, 90, and 120 minutes for optimal discrimination between macroadenoma and microadenoma were 5.6, 5.7, 6.3, 6.0, and 5.8 ng/mL, respectively. ROC curve analysis revealed that the GH value at 30 minutes had the highest area under the curve.ConclusionThe GH level of 5.7 ng/mL or higher at 30 minutes during OGTT could provide sufficient information to detect macroadenoma at the time of diagnosis.

BackgroundMetabolic syndrome (MetS) is a condition characterized by a cluster of metabolic disorders and is associated with increased risk of cardiovascular disease (CVD). This study analyzed data from the Korean Health and Genome Study to examine the impact of MetS on CVD.MethodsA total of 8,898 subjects (4,241 males and 4,657 females), 40 to 69 years of age, were enrolled and evaluated for the development of new onset CVD from 2001 to 2012 (median 8.1 years of follow-up).ResultsThe prevalence of MetS at baseline was 22.0% (932/4,241) and 29.7% (1,383/4,657) in males and females, respectively. MetS was associated with increased risk of coronary heart disease (CHD; hazard ratio [HR], 1.818; 95% confidence interval [CI], 1.312 to 2.520 in males; HR, 1.789; 95% CI, 1.332 to 2.404 in females) and CVD (HR, 1.689; 95% CI, 1.295 to 2.204 in males; HR, 1.686; 95% CI, 1.007 to 2.192 in females). Specifically, MetS was associated with risk of future stroke in females only (HR, 1.486; 95% CI, 1.007 to 2.192). Among MetS components, abdominal obesity and hypertension were independent predictors of both CHD and CVD. In addition, a higher number of MetS components correlated with higher CVD risk.ConclusionMetS is a significant risk factor for the development of CVD although its impact varies between sexes.

This study was conducted to investigate whether baseline lung function or change in lung function is associated with the development of metabolic syndrome (MS) in Koreans. We analyzed clinical and laboratory data from 3,768 Koreans aged 40-60 years who underwent medical check-ups over a six-year period between 2006 and 2012. We calculated the percent change in forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1) over the study period. We tested for an association between baseline lung function or lung function change during the follow-up period and the development of MS. The 533 subjects (14.1%) developed MS after the six-year follow-up. The baseline FVC and FEV1 were not different between the subjects who developed MS after six years and the subject without MS after six years. The percent change in FVC over six years in subjects who developed MS after six years was higher than that in subjects who did not develop MS (-5.75 [-10.19 --1.17], -3.29 [-7.69-1.09], respectively, P = 0.001). The percent change in FVC over six years was associated with MS development after adjusting for age, sex, body mass index (BMI), glucose, HDL, triglyceride, waist circumferences (WC), and systolic blood pressure. However, these association was not significant after adjusting for change of BMI and change of WC over six years (P = 0.306). The greater change in vital capacity over six years of follow-up was associated with MS development, predominantly due to obesity and abdominal obesity. The prospective study is needed to determine the relationship between lung function decline and MS.

The effect of subclinical thyroid dysfunction on vascular atherosclerosis remains uncertain. The objective of this study was to elucidate the association between sustained subclinical thyroid dysfunction and carotid plaques, which are an early surrogate marker of systemic atherosclerosis.The study included 21,342 adults with consistent thyroid hormonal status on serial thyroid function tests (TFTs) and carotid artery duplex ultrasonography at a health screening center between 2007 and 2014. The effect of subclinical thyroid dysfunction on baseline carotid plaques and newly developed carotid plaques during 5-year follow-up was determined by logistic regression analyses and GEE (Generalized Estimating Equations), respectively.Carotid plaques were more common in the subclinical hypothyroidism (55.6%) than the euthyroidism (47.8%) at baseline. However, in multivariable analysis, thyroid status was not a significant risk for the carotid plaques at baseline. Instead, traditional cardiovascular risk factors, such as age (P

Serum albumin concentration is associated with both type 2 diabetes and metabolic syndrome (MetS). We sought to investigate whether baseline serum albumin and change in serum albumin could be independent risk factors for prediabetes in subjects without MetS. We further examined the effect of serum albumin on progression to overt diabetes in subjects who developed prediabetes.Among 10,792 participants without diabetes and MetS who consecutively underwent yearly health check-ups over six years, 9,807 subjects without incident MetS were enrolled in this longitudinal retrospective study. The risk of developing prediabetes (impared fasting glucose or hemoglobin A1c) was analyzed according to baseline and percent change in serum albumin concentration using Cox regression analysis. Serial changes in serum albumin concentration were measured from baseline to one year before prediabetes diagnosis, and then from the time of prediabetes diagnosis to progression to overt diabetes or final follow-up.A total of 4,398 incident cases of prediabetes developed during 35,807 person-years (median 3.8 years). The hazard ratio for incident prediabetes decreased as percent change in serum albumin concentration (quartiles and per 1%) increased in a crude and fully adjusted model. However, baseline serum albumin concentration itself was not associated with prediabetic risk. Serum albumin levels kept increasing until the end of follow-up in prediabetic subjects who returned to normal glycemic status, whereas these measures did not change in prediabetic subjects who developed type 2 diabetes. Serum albumin concentration measured at the end of follow-up was the highest in the regression group, compared to the stationary (p = 0.014) or progression groups (p = 0.009).Increase in serum albumin concentration might protect against early glycemic deterioration and progression to type 2 diabetes even in subjects without MetS.

BackgroundSmall dense low density lipoprotein (sdLDL) has recently emerged as an important risk factor of coronary heart disease.MethodsThe mean LDL particle size was measured in 203 patients with type 2 diabetes mellitus (T2DM) and 212 matched subjects without diabetes using polyacrylamide tube gel electrophoresis. Major vascular complications were defined as stroke, angiographically-documented coronary artery disease or a myocardial infarction. Peripheral vascular stenosis, carotid artery stenosis (≥50% in diameter) or carotid artery plaque were considered minor vascular complications. Overall vascular complications included both major and minor vascular complications.ResultsDiabetic patients had significantly smaller mean-LDL particle size (26.32 nm vs. 26.49 nm) and a higher percentage of sdLDL to total LDL compared to those of subjects without diabetes (21.39% vs. 6.34%). The independent predictors of sdLDL in this study were serum triglyceride level and body mass index (odds ratio [OR], 1.020 with P

BackgroundTo evaluate the clinical efficacy of sitagliptin for reducing plasma glucose levels in Korean subjects with type 2 diabetes mellitus during a 14-week treatment period.MethodsOur study design involved the addition of 100 mg sitagliptin once-daily to three ongoing combination therapy regimens and changing from glimepiride and metformin to sitagliptin and metformin.ResultsThe addition of sitagliptin 100 mg/day produced a statistically significant reduction in mean HbA1c level (mean HbA1c reduction of 0.99±0.85%, P

To investigate the therapeutic efficacy and mechanism of β-cells with insulin receptor (IR) overexpression on diabetes mellitus (DM), rat insulinoma (INS-1) cells were engineered to stably express human insulin receptor (INS-IR cells), and subsequently transplanted into streptozotocin- induced diabetic rats. Compared with INS-1 cells, INS-IR cells showed improved β-cell function, including the increase in glucose utilization, calcium mobilization, and insulin secretion, and exhibited a higher rate of cell proliferation, and maintained lower levels of blood glucose in diabetic rats. These results were attributed to the increase of β-catenin/PPARγ complex bindings to peroxisome proliferator response elements in rat glucokinase (GK) promoter and the prolongation of S-phase of cell cycle by cyclin D1. These events resulted from more rapid and higher phosphorylation levels of insulin-signaling intermediates, including insulin receptor substrate (IRS)-1/IRS-2/phosphotylinositol 3 kinase/v-akt murine thymoma viral oncogene homolog (AKT) 1, and the consequent enhancement of β-catenin nuclear translocation and Wnt responsive genes including GK and cyclin D1. Indeed, the higher functionality and proliferation shown in INS-IR cells were offset by β-catenin, cyclin D1, GK, AKT1, and IRS-2 gene depletion. In addition, the promotion of cell proliferation and insulin secretion by Wnt signaling activation was shown by 100 nM insulin treatment, and to a similar degree, was shown in INS-IR cells. In this regard, this study suggests that transferring INS-IR cells into diabetic animals is an effective and feasible DM treatment. Accordingly, the method might be a promising alternative strategy for treatment of DM given the adverse effects of insulin among patients, including the increased risk of modest weight gain and hypoglycemia. Additionally, this study demonstrates that the novel mechanism of cross-talk between insulin and Wnt signaling plays a primary role in the higher therapeutic efficacy of IR-overexpressing β-cells.

BACKGROUND:It has been reported that peroxisome proliferator-activated receptor (PPAR)-γ and their synthetic ligands have direct effects on pancreatic β-cells. We investigated whether PPAR-γ activation stimulates insulin secretion through the up-regulation of GPR40 in pancreatic β-cells. METHODS:Rat insulinoma INS-1 cells and primary rat islets were treated with rosiglitazone (RGZ) and/or adenoviral PPAR-γ overexpression. OLETF rats were treated with RGZ. RESULTS:PPAR-γ activation with RGZ and/or adenoviral PPAR-γ overexpression increased free fatty acid (FFA) receptor GPR40 expression, and increased insulin secretion and intracellular calcium mobilization, and was blocked by the PLC inhibitors, GPR40 RNA interference, and GLUT2 RNA interference. As a downstream signaling pathway of intracellular calcium mobilization, the phosphorylated levels of CaMKII and CREB, and the downstream IRS-2 and phospho-Akt were significantly increased. Despite of insulin receptor RNA interference, the levels of IRS-2 and phospho-Akt was still maintained with PPAR-γ activation. In addition, the β-cell specific gene expression, including Pdx-1 and FoxA2, increased in a GPR40- and GLUT2-dependent manner. The levels of GPR40, phosphorylated CaMKII and CREB, and β-cell specific genes induced by RGZ were blocked by GW9662, a PPAR-γ antagonist. Finally, PPAR-γ activation up-regulated β-cell gene expressions through FoxO1 nuclear exclusion, independent of the insulin signaling pathway. Based on immunohistochemical staining, the GLUT2, IRS-2, Pdx-1, and GPR40 were more strongly expressed in islets from RGZ-treated OLETF rats compared to control islets. CONCLUSION:These observations suggest that PPAR-γ activation with RGZ and/or adenoviral overexpression increased intracellular calcium mobilization, insulin secretion, and β-cell gene expression through GPR40 and GLUT2 gene up-regulation.