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Aims/hypothesis There is limited information on how polygenic scores (PSs), based on variants from genome-wide association studies (GWASs) of type 2 diabetes, add to clinical variables in predicting type 2 diabetes incidence, particularly in non-European-ancestry populations. Methods For participants in a longitudinal study in an Indigenous population from the Southwestern USA with high type 2 diabetes prevalence, we analysed ten constructions of PS using publicly available GWAS summary statistics. Type 2 diabetes incidence was examined in three cohorts of individuals without diabetes at baseline. The adult cohort, 2333 participants followed from age ≥20 years, had 640 type 2 diabetes cases. The youth cohort included 2229 participants followed from age 5–19 years (228 cases). The birth cohort included 2894 participants followed from birth (438 cases). We assessed contributions of PSs and clinical variables in predicting type 2 diabetes incidence. Results Of the ten PS constructions, a PS using 293 genome-wide significant variants from a large type 2 diabetes GWAS meta-analysis in European-ancestry populations performed best. In the adult cohort, the AUC of the receiver operating characteristic curve for clinical variables for prediction of incident type 2 diabetes was 0.728; with the PS, 0.735. The PS’s HR was 1.27 per SD (p=1.6 × 10−8; 95% CI 1.17, 1.38). In youth, corresponding AUCs were 0.805 and 0.812, with HR 1.49 (p=4.3 × 10−8; 95% CI 1.29, 1.72). In the birth cohort, AUCs were 0.614 and 0.685, with HR 1.48 (p=2.8 × 10−16; 95% CI 1.35, 1.63). To further assess the potential impact of including PS for assessing individual risk, net reclassification improvement (NRI) was calculated: NRI for the PS was 0.270, 0.268 and 0.362 for adult, youth and birth cohorts, respectively. For comparison, NRI for HbA1c was 0.267 and 0.173 for adult and youth cohorts, respectively. In decision curve analyses across all cohorts, the net benefit of including the PS in addition to clinical variables was most pronounced at moderately stringent threshold probability values for instituting a preventive intervention. Conclusions/interpretation This study demonstrates that a European-derived PS contributes significantly to prediction of type 2 diabetes incidence in addition to information provided by clinical variables in this Indigenous study population. Discriminatory power of the PS was similar to that of other commonly measured clinical variables (e.g. HbA1c). Including type 2 diabetes PS in addition to clinical variables may be clinically beneficial for identifying individuals at higher risk for the disease, especially at younger ages. Graphical abstract

Context Insulin secretion and sensitivity regulate glycemia, with inadequately compensated deficiencies leading to diabetes. Objective We investigated effects of weight loss, an intensive lifestyle intervention (ILS), and metformin on the relationship between insulin secretion and sensitivity using repository data from 2931 participants in the Diabetes Prevention Program clinical trial in adults at high risk of developing type 2 diabetes. Methods Insulin secretion and sensitivity were estimated from insulin and glucose concentrations in fasting and 30-minute postload serum samples at baseline and 1, 2, and 3 years after randomization, during the active intervention phase. The nonlinear relationship of secretion and sensitivity was evaluated by standardized major axis regression to account for variability in both variables. Insulin secretory demand and compensatory insulin secretion were characterized by distances along and away from the regression line, respectively. Results ILS and metformin decreased secretory demand while increasing compensatory insulin secretion, with greater effects of ILS. Improvements were directly related to weight loss; decreased weight significantly reduced secretory demand (b=−0.144 SD; 95% CI (−0.162, −0.125)/5 kg loss) and increased compensatory insulin secretion (b = 0.287 SD, 95% CI (0.261, 0.314)/5 kg loss). In time-dependent hazard models, increasing compensatory insulin secretion (hazard ratio [HR] = 0.166 per baseline SD, 95% CI 0.133, 0.206) and weight loss (HR = 0.710 per 5 kg loss, 95% CI 0.613, 0.819) predicted lower diabetes risk. Conclusion Diabetes risk reduction was directly related to the amount of weight loss, an effect mediated by lowered insulin secretory demand (due to increased insulin sensitivity) coupled with improved compensatory insulin secretion.

Growth abnormalities in childhood have been related to later cardiometabolic risks, but little is known about these associations in populations at high risk of type 2 diabetes.We examined the associations of patterns of growth, including weight and height at ages 1-59 months, with cardiometabolic risk factors at ages 5-16 years.We linked anthropometric data collected at ages 1-59 months to cardiometabolic data obtained from a longitudinal study in a southwestern American Indian population at high risk of diabetes. Analyses included 701 children with ≥1 follow-up examination at ages 5-16 years. We derived age- and sex-specific weight-for-height z-scores (WHZ) and height-for-age z-scores (HAZ) at ages 1-59 months. We selected the highest observed WHZ and the lowest observed HAZ at ages 1-59 months and analyzed associations of z-scores and categories of WHZ and HAZ with cardiometabolic outcomes at ages 5-16 years. We used linear mixed-effects models to account for repeated measures.Overweight/obesity (WHZ 2) at ages 1-59 months was significantly associated with increased BMI, fasting and 2-hour postload plasma glucose, fasting and 2-hour insulin, triglycerides, systolic blood pressure, diastolic blood pressure, and decreased HDL cholesterol at ages 5-16 years relative to normal weight (WHZ ≤1). For example, at ages 5-9 years, 2-hour glucose was 10.4 mg/dL higher (95% CI: 5.6-15.3 mg/dL) and fasting insulin was 4.29 μU/mL higher (95% CI: 2.96-5.71 μU/mL) in those with overweight/obesity in early childhood. Associations were attenuated and no longer significant when adjusted for concurrent BMI. A low height-for-age (HAZ-2) at ages 1-59 months was associated with 5.37 mg/dL lower HDL (95% CI: 2.57-8.17 mg/dL) and 27.5 μU/mL higher 2-hour insulin (95% CI: 3.41-57.6 μU/mL) at ages 10-16 years relative to an HAZ ≥0.In this American Indian population, findings suggest a strong contribution of overweight/obesity in early childhood to cardiometabolic risks in later childhood and adolescence, mediated through persistent overweight/obesity into later ages. Findings also suggest potential adverse effects of low height-for-age, which require confirmation.

Insulin-like growth factor binding protein 4 (IGFBP4) is involved in adipogenesis, and IGFBP4 null mice have decreased body fat through decreased PPAR-γ expression. In the current study, we assessed whether variation in the IGFBP4 coding region influences body mass index (BMI) in American Indians who are disproportionately affected by obesity. Whole exome sequence data from a population-based sample of 6779 American Indians with longitudinal measures of BMI were used to identify variation in IGFBP4 that associated with BMI. A novel variant that predicts a p.Ser76Thr in IGFBP4 (Thr-allele frequency = 0.02) was identified which associated with the maximum BMI measured during adulthood (BMI 39.8 kg/m

There is evidence suggesting that infection with SARS-CoV-2 can lead to several long-term sequelae including diabetes. This mini-review examines the rapidly evolving and conflicting literature on new-onset diabetes after COVID-19, which we term NODAC. We searched PubMed, MEDLINE, and medRxiv from inception until December 1, 2022 using both MeSH terms and free text words including “COVID-19,” “SARS-CoV-2,” “diabetes,” “hyperglycemia,” “insulin resistance,” and “pancreatic β-cell.” We also supplemented searches by examining reference lists from retrieved articles. Current evidence suggests that COVID-19 increases the risk of developing diabetes, but the attributable risk is uncertain due to limitations of study designs and the evolving nature of the pandemic, including new variants, widespread population exposure to the virus, diagnostic options for COVID-19 and vaccination status. The etiology of diabetes after COVID-19 is likely multifactorial and includes factors associated with host characteristics (e.g., age), social determinants of health (e.g., deprivation index), and pandemic-related effects both at the personal (e.g., psychosocial stress) and the societal-community level (e.g., containment measures). COVID-19 may have direct and indirect effects on pancreatic β-cell function and insulin sensitivity related to: the acute infection and its treatment (e.g., glucocorticoids); autoimmunity; persistent viral residency in multiple organs including adipose tissue; endothelial dysfunction; and hyperinflammatory state. While our understanding of NODAC continues to evolve, consideration should be given for diabetes to be classified as a post-COVID syndrome, in addition to traditional classifications of diabetes (e.g., type 1 or type 2), so that the pathophysiology, natural history and optimal management can be studied.

Early puberty onset is associated with higher risk of diabetes, but most studies have not accounted for childhood factors that may confound the association. Using data from a study conducted in an Indigenous community in Arizona (1965-2007) we examined associations of timing and velocity of the adolescent growth spurt with type 2 diabetes, and whether these associations are mediated by childhood BMI and insulinemia. Adolescent growth parameters were derived from the Preece-Baines growth model, a parametric growth curve fitted to longitudinal height data, in 861 participants with height measurements spanning the whole period of growth. In males, older age at take-off, age at peak velocity and age at maturation were associated with decreased prevalence of diabetes (odds ratio [OR]=0.43 per year, 95% CI 0.27-0.69; OR=0.50, 95% CI 0.35-0.72; OR=0.58, 95% CI, 0.41-0.83, respectively), while higher velocity at take-off was associated with increased risk (OR=3.47 per cm/yr, 95% CI 1.87-6.42) adjusting for age, birth year and maternal diabetes. Similar results were observed with incident diabetes. Our findings suggest that an early and accelerated adolescent growth spurt is a risk factor for diabetes, at least in males. These associations are only partially explained by measures of adiposity and insulinemia.

Genome-wide association studies have identified single nucleotide polymorphisms (SNPs) associated with waist circumference and waist-to-hip ratio adjusted for body mass index (WCadjBMI, WHRadjBMI), but it remains unclear whether these SNPs relate to change in WCadjBMI or WHRadjBMI with lifestyle intervention. We hypothesized that polygenic scores (PS) comprised of 59 SNPs previously associated with central adiposity would predict less of a reduction in WCadjBMI or WHRadjBMI at eight-to-ten weeks in two lifestyle intervention trials, NUGENOB and DiOGenes, and at one year in 5 lifestyle intervention trials, Look AHEAD, Diabetes Prevention Program, Diabetes Prevention Study, DIETFITS, and PREDIMED-Plus. One standard deviation higher PS related to smaller one-year change in WCadjBMI in the lifestyle intervention arms at year 1, and thus predicted poorer response (beta=0.007, SE=0.003, p=0.03) among White participants overall and in White men (beta=0.01, SE=0.004, p=0.01). At average weight loss, this amounted to 0.20-0.28 cm per standard deviation. No significant findings emerged in White women, African American men, for the 8-10 week outcomes or for WHRadjBMI. Findings were heterogeneous in African American women. These results indicate that polygenic risk relates to change in WCadjBMI with lifestyle intervention but the effects are small and not of sufficient magnitude to be clinically significant.

INTRODUCTION: We estimated the effects of cardiorespiratory fitness (CRF) and body mass index (BMI) at baseline on mortality and cardiovascular disease events in people with type 2 diabetes that participated in the Look AHEAD randomized clinical trial. METHODS: Look AHEAD compared effects of an intensive lifestyle intervention with diabetes support and education on cardiovascular disease events in 5,145 adults aged 45–76 years with overweight/obesity and type 2 diabetes. In 4,773 participants, we performed a secondary analysis of the association of baseline CRF during maximal treadmill test (expressed as metabolic equivalents, METs) on mortality and cardiovascular disease events during mean follow-up of 9.2 years. RESULTS: The mean (SD) CRF was 7.2 (2.0) METs. Adjusted for age, sex, race/ethnicity, body mass index, intervention group, and β-blocker use, all-cause mortality rate was 30% lower per SD greater METs (hazard ratio, HR=0.70, 95% CI 0.60–0.81; rate difference, RD=−2.71 deaths/1000 person-years, 95% CI −3.79 to −1.63). Similarly, a SD greater METs predicted lower cardiovascular disease mortality (HR=0.45, RD =−1.65 cases/1000 person-years) and a composite cardiovascular outcome (HR= 0.72; RD=−6.38). Effects of METs were homogeneous on the HR scale for most baseline variables and outcomes but heterogeneous for many on the RD scale, with greater RDs in subgroups at greater risk of the outcomes. For example, all-cause mortality was lower by 7.6 deaths/1000 person-years per SD greater METs in those with a history of cardiovascular disease at baseline but lower by only 1.6 in those without such history. BMI adjusted for CRF had little or no effect on these outcomes. CONCLUSIONS: Greater CRF is associated with reduced risks of mortality and cardiovascular disease events.

Genome-wide significant loci for metformin response in type 2 diabetes reported elsewhere have not replicated in the Diabetes Prevention Program (DPP). To assess pharmacogenetic interactions in pre-diabetes, we conducted a genome-wide association study (GWAS) in the DPP. Cox proportional hazards models tested associations with diabetes incidence in metformin (MET, n=876) and placebo (PBO, n=887) arms. Multiple linear regression assessed association with one-year change in metformin-related quantitative traits, adjusted for baseline trait, age, sex, and 10 ancestry principal components. We tested for gene-by-treatment interaction. No significant associations emerged for diabetes incidence. We identified four genome-wide significant variants after correcting for correlated traits (pENOSF1 (minor allele frequency [MAF]AFR=0.07, MAFEUR=0.002) was associated with an increase in % glycated hemoglobin (per minor allele β=0.39 [95% CI 0.28, 0.50], p=2.8×10-12). Rs145591055 near OMSR (MAF=0.10 in American Indians), was associated with weight loss (kg) (per G allele β=-7.55 [95% CI -9.88, -5.22], p=3.2×10-10) in MET. Neither variant was significant in PBO; gene-by-treatment interaction was significant for both variants (p(G×T)

Age-related macular degeneration (AMD) is a leading cause of blindness with no treatment available for early stages. Retrospective studies have shown an association between metformin and reduced risk of AMD.To investigate the association between metformin use and age-related macular degeneration (AMD).The Diabetes Prevention Program Outcomes Study is a cross-sectional follow-up phase of a large multicenter randomized clinical trial, Diabetes Prevention Program (1996-2001), to investigate the association of treatment with metformin or an intensive lifestyle modification vs placebo with preventing the onset of type 2 diabetes in a population at high risk for developing diabetes. Participants with retinal imaging at a follow-up visit 16 years posttrial (2017-2019) were included. Analysis took place between October 2019 and May 2022.Participants were randomly distributed between 3 interventional arms: lifestyle, metformin, and placebo.Prevalence of AMD in the treatment arms.Of 1592 participants, 514 (32.3%) were in the lifestyle arm, 549 (34.5%) were in the metformin arm, and 529 (33.2%) were in the placebo arm. All 3 arms were balanced for baseline characteristics including age (mean [SD] age at randomization, 49 [9] years), sex (1128 [71%] male), race and ethnicity (784 [49%] White), smoking habits, body mass index, and education level. AMD was identified in 479 participants (30.1%); 229 (14.4%) had early AMD, 218 (13.7%) had intermediate AMD, and 32 (2.0%) had advanced AMD. There was no significant difference in the presence of AMD between the 3 groups: 152 (29.6%) in the lifestyle arm, 165 (30.2%) in the metformin arm, and 162 (30.7%) in the placebo arm. There was also no difference in the distribution of early, intermediate, and advanced AMD between the intervention groups. Mean duration of metformin use was similar for those with and without AMD (mean [SD], 8.0 [9.3] vs 8.5 [9.3] years; P = .69). In the multivariate models, history of smoking was associated with increased risks of AMD (odds ratio, 1.30; 95% CI, 1.05-1.61; P = .02).These data suggest neither metformin nor lifestyle changes initiated for diabetes prevention were associated with the risk of any AMD, with similar results for AMD severity. Duration of metformin use was also not associated with AMD. This analysis does not address the association of metformin with incidence or progression of AMD.

Genome-wide significant loci for metformin response in type 2 diabetes reported elsewhere have not replicated in the Diabetes Prevention Program (DPP). To assess pharmacogenetic interactions in pre-diabetes, we conducted a genome-wide association study (GWAS) in the DPP. Cox proportional hazards models tested associations with diabetes incidence in metformin (MET, n=876) and placebo (PBO, n=887) arms. Multiple linear regression assessed association with one-year change in metformin-related quantitative traits, adjusted for baseline trait, age, sex, and 10 ancestry principal components. We tested for gene-by-treatment interaction. No significant associations emerged for diabetes incidence. We identified four genome-wide significant variants after correcting for correlated traits (p

OBJECTIVE To determine whether metformin or lifestyle modification can lower rates of all-cause and cause-specific mortality in the Diabetes Prevention Program and Diabetes Prevention Program Outcomes Study. RESEARCH DESIGN AND METHODS From 1996 to 1999, 3,234 adults at high risk for type 2 diabetes were randomized to an intensive lifestyle intervention, masked metformin, or placebo. Placebo and lifestyle interventions stopped in 2001, and a modified lifestyle program was offered to everyone, but unmasked study metformin continued in those originally randomized. Causes of deaths through 31 December 2018 were adjudicated by blinded reviews. All-cause and cause-specific mortality hazard ratios (HRs) were estimated from Cox proportional hazards regression models and Fine-Gray models, respectively. RESULTS Over a median of 21 years (interquartile range 20–21), 453 participants died. Cancer was the leading cause of death (n = 170), followed by cardiovascular disease (n = 131). Compared with placebo, metformin did not influence mortality from all causes (HR 0.99 [95% CI 0.79, 1.25]), cancer (HR 1.04 [95% CI 0.72, 1.52]), or cardiovascular disease (HR 1.08 [95% CI 0.70, 1.66]). Similarly, lifestyle modification did not impact all-cause (HR 1.02 [95% CI 0.81, 1.28]), cancer (HR 1.07 [95% CI 0.74, 1.55]), or cardiovascular disease (HR 1.18 [95% CI 0.77, 1.81]) mortality. Analyses adjusted for diabetes status and duration, BMI, cumulative glycemic exposure, and cardiovascular risks yielded results similar to those for all-cause mortality. CONCLUSIONS Cancer was the leading cause of mortality among adults at high risk for type 2 diabetes. Although metformin and lifestyle modification prevented diabetes, neither strategy reduced all-cause, cancer, or cardiovascular mortality rates.

Albuminuria is an under-recognized component of chronic kidney disease definition, staging, and prognosis. Guidelines, particularly for hypertension, conflict on recommendations for urine albumin-to-creatinine ratio (ACR) measurement. Separately among 1 344 594 adults with diabetes and 2 334 461 nondiabetic adults with hypertension from the chronic kidney disease Prognosis Consortium, we assessed ACR testing, estimated the prevalence and incidence of ACR ≥30 mg/g and developed risk models for ACR ≥30 mg/g. The ACR screening rate (cohort range) was 35.1% (12.3%–74.5%) in diabetes and 4.1% (1.3%–20.7%) in hypertension. Screening was largely unrelated to the predicted risk of prevalent albuminuria. The median prevalence of ACR ≥30 mg/g across cohorts was 32.1% in diabetes and 21.8% in hypertension. Higher systolic blood pressure was associated with a higher prevalence of albuminuria (odds ratio [95% CI] per 20 mm Hg in diabetes, 1.50 [1.42–1.60]; in hypertension, 1.36 [1.28–1.45]). The ratio of undetected (due to lack of screening) to detected ACR ≥30 mg/g was estimated at 1.8 in diabetes and 19.5 in hypertension. Among those with ACR

ImportanceLatino youths are disproportionately impacted by prediabetes and type 2 diabetes (T2D). Lifestyle intervention is the first-line approach for preventing or delaying T2D among adults with prediabetes.ObjectiveTo assess the efficacy of a diabetes prevention program among Latino youths aged 12 to 16 years with prediabetes.Design, Setting, and ParticipantsThis 2-group parallel randomized clinical trial with 2:1 randomization assessed a lifestyle intervention against usual care among Latino youths with prediabetes and obesity with 6- and 12-month follow-up. The study was conducted at YMCA facilities in Phoenix, Arizona from May 2016 to March 2020.InterventionParticipants were randomized to lifestyle intervention (INT) or usual care control (UCC). The 6-month INT included 1 d/wk of nutrition and health education and 3 d/wk of physical activity. UCC included 2 visits with a pediatric endocrinologist and a bilingual, bicultural registered dietitian to discuss diabetes risks and healthy lifestyle changes.Main Outcomes and MeasuresInsulin sensitivity, glucose tolerance, and weight-specific quality of life (YQOL-W) at 6- and 12-month follow-up.ResultsA total of 117 Latino youths (mean [SD] age, 14 [1] years; 47 [40.1%] girls) were included in the analysis. Overall, 79 were randomized to INT and 38 to UCC. At 6 months, the INT led to significant decreases in mean (SE) 2-hour glucose (baseline: 144 [3] mg/dL; 6 months: 132 [3] mg/dL; P = .002) and increases in mean (SE) insulin sensitivity (baseline: 1.9 [0.2]; 6 months: 2.6 [0.3]; P = .001) and YQOL-W (baseline: 75 [2]; 6 months: 80 [2]; P = .006), but these changes were not significantly different from UCC (2-hour glucose: mean difference, −7.2 mg/dL; 95% CI, −19.7 to 5.3 mg/dL; P for interaction = .26; insulin sensitivity: mean difference, 0.1; 95% CI, −0.7 to 0.9; P for interaction = .79; YQOL-W: mean difference, 6.3; 95% CI, −1.1 to 13.7; P for interaction = .10, respectively). Both INT (mean [SE], −15 mg/dL [4.9]; P = .002) and UCC (mean [SE], −15 mg/dL [5.4]; P = .005) had significant 12-month reductions in 2-hour glucose that did not differ significantly from each other (mean difference, −0.3; 95% CI, −14.5 to 14.1 mg/dL; P for interaction = .97). At 12 months, changes in mean (SE) insulin sensitivity in INT (baseline: 1.9 [0.2]; 12 months: 2.3 [0.2]; P = .06) and UCC (baseline: 1.9 [0.3]; 12 months: 2.0 [0.2]; P = .70) were not significantly different (mean difference, 0.3; 95% CI, −0.4 to 1.0; P for interaction = .37). At 12 months, YQOL-W was significantly increased in INT (basline: 75 [2]; 12 months: 82 [2]; P P for interaction = .03).Conclusions and RelevanceIn this randomized clinical trial, both INT and UCC led to similar changes in T2D risk factors among Latino youths with prediabetes; however, YQOL-W was improved in INT compared with UCC. Diabetes prevention interventions that are effective in adults also appeared to be effective in high risk youths.Trial RegistrationClinicalTrials.gov Identifier: NCT02615353

BACKGROUND AND OBJECTIVES: Low serum 25-hydroxyvitamin D (25[OH]D) concentration has been associated with higher levels of proteinuria and lower levels of eGFR in observational studies. In the Vitamin D and Type 2 Diabetes (D2d) study, we investigated the effect of vitamin D supplementation on kidney outcomes in a population with prediabetes. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Overweight/obese adults with high risk for type 2 diabetes (defined by meeting two of three glycemic criteria for prediabetes) were randomized to vitamin D(3) 4000 IU per day versus placebo. Median duration of treatment was 2.9 years (interquartile range 2.0–3.5 years). Kidney outcomes included (1) worsening in Kidney Disease: Improving Global Outcomes (KDIGO ) risk score (low, moderate, high, very high) on two consecutive follow-up visits after the baseline visit and (2) mean changes in eGFR and urine albumin-to-creatinine ratio (UACR). RESULTS: Among 2166 participants (mean age 60 years, body mass index 32 kg/m(2), serum 25(OH)D 28 ng/ml, eGFR 87 ml/min per 1.73 m(2), UACR 11 mg/g, 79% with hypertension), 10% had moderate, high, or very high KDIGO risk score. Over a median follow-up of 2.9 years, there were 28 cases of KDIGO worsening in the vitamin D group and 30 in the placebo group (hazard ratio, 0.89; 95% confidence interval [95% CI], 0.52 to 1.52]). Mean difference in eGFR from baseline was −1.0 ml/min per 1.73 m(2) (95% CI, −1.3 to −0.7) in the vitamin D group and −0.1 ml/min per 1.73 m(2) (95% CI, −0.4 to 0.2) in the placebo group; between-group difference was −1.0 ml/min per 1.73 m(2) (95% CI, −1.4 to −0.6). Mean difference in UACR was 2.7 mg/g (95% CI, 1.2 to 4.3) in the vitamin D group and 2.0 (95% CI, 0.5 to 3.6) in the placebo group; between-group difference was 0.7 mg/g (95% CI, −1.5 to 2.9). CONCLUSIONS: Among persons with prediabetes, who were not preselected on the basis of serum 25(OH)D concentration, vitamin D supplementation did not affect progression of KDIGO risk scores and did not have a meaningful effect on change in UACR or eGFR.

Objective The Action for Health in Diabetes (Look AHEAD) study previously reported that intensive lifestyle intervention (ILI) reduced incident depressive symptoms and improved health-related quality of life (HRQOL) over nearly 10 years of intervention compared with a control group (the diabetes support and education group [DSE]) in participants with type 2 diabetes and overweight or obesity. The present study compared incident depressive symptoms and changes in HRQOL in these groups for an additional 6 years following termination of the ILI in September 2012. Methods A total of 1,945 ILI participants and 1,900 DSE participants completed at least one of four planned postintervention assessments at which weight, mood (via the Patient Health Questionnaire-9), antidepressant medication use, and HRQOL (via the Medical Outcomes Scale, Short Form-36) were measured. Results ILI participants and DSE participants lost 3.1 (0.3) and 3.8 (0.3) kg [represented as mean (SE); p = 0.10], respectively, during the 6-year postintervention follow-up. No significant differences were observed between groups during this time in incident mild or greater symptoms of depression, antidepressant medication use, or in changes on the physical component summary or mental component summary scores of the Short Form-36. In both groups, mental component summary scores were higher than physical component summary scores. Conclusions Prior participation in the ILI, compared with the DSE group, did not appear to improve subsequent mood or HRQOL during 6 years of postintervention follow-up.

While the samples and data from the Pima Indians of the Gila River Indian Community have been included in many international HLA workshops and conferences and have been the focus of numerous population reports and the source of novel alleles at the classical HLA loci, they have not been studied for the non-classical loci. In order to expand our HLA-disease association studies, we typed over 300 whole genome sequences from full Pima heritage members, controlled for first degree relationship, and employed recently developed computer algorithms to resolve HLA alleles. Both classical-HLA-A, -B, and -C- and non-classical- HLA-E, -F, -G, -J, -L, -W, -Y, -DPA2, -DPB2, -DMA, -DMB, -DOA, -DRB2, -DRB9, TAP1- loci were typed at the 4-field level of resolution. We present allele and selected haplotype frequencies, test the genotype distributions for population structure, discuss the issues that are created for tests of Hardy-Weinberg equilibrium over the four sample spaces of high resolution HLA typing, and address the implications for the evolution of non-classical pseudogenes that are no longer expressed in a phenotype subject to natural selection.

Background: Some studies suggest that earlier pubertal development is associated with obesity and metabolic disorders in adulthood, but whether accelerated adolescent linear growth spurt influences type 2 diabetes (T2D) in populations at high risk of diabetes is unclear. Aim: To examine associations of age at initiation of the adolescent growth spurt (i.e., take-off) (ATO) , velocity at take-off (VTO) , and age at peak velocity (APV) with T2D incidence. Methods: Height measurements obtained from a longitudinal study of diabetes in American Indians were used to estimate biological growth parameters using the Preece-Baines growth model I, a parametric model of the human growth curve. Diabetes incidence was analyzed among individuals who had ≥ 4 height examinations at ages 5-17 years and who remained nondiabetic at first examination after age 18. Participants were followed until diabetes developed or last examination. Associations of growth parameters with diabetes incidence were analyzed by Poisson regression. Results: Among 649 originally nondiabetic participants, 135 females and 82 males developed diabetes in a median follow-up of years. With adjustment for age, birth date and maternal diabetes, younger ATO and APV were associated with T2D incidence in males (incidence rate ratio (IRR) =1.75 per year, 95% CI, 1.23, 2.50; and IRR=1.33, 95% CI, 1.01, 1.75, respectively) but not in females (IRR=0.93, 95% CI, 0.75, 1.16; and IRR=1.04, 95% CI, 0.86, 1.26, respectively) . Higher VTO was associated with T2D incidence in males (IRR=1.80 per cm/y, 95% CI, 1.15, 2.81) but not in females (IRR=1.15, 95% CI, 0.88, 1.50) . With further adjustment for adult and childhood BMI and fasting insulin, the associations were attenuated for APV and VTO but remained significant for ATO in males. Conclusion: Our findings suggest that an early and accelerated adolescent growth spurt is a risk factor for T2D, at least in males. These associations are only partially explained by measures of adiposity and insulinemia. Disclosure M.J.Ramirez-luzuriaga: n/a. S.Kobes: None. M.Sinha: None. W.C.Knowler: None. R.L.Hanson: None.

Introduction: Latino youth are disproportionately impacted by prediabetes and type 2 diabetes (T2D) . Lifestyle intervention is the first line approach for preventing or delaying T2D among adults with prediabetes. We assessed the efficacy of a diabetes prevention program among Latino youth with prediabetes. Methods: A total of 117 Latino youth (mean±SD, age 13.5±1.4) with prediabetes and obesity were randomized to lifestyle intervention (INT) or usual care (UC) . The 6-month INT (n=79) included 1 d/wk of nutrition education and training and 3 d/wk of physical activity. UC (n=38) included 2 visits with a pediatric endocrinologist and registered dietitian to discuss diabetes risks and healthy lifestyle changes. A 75-g oral glucose tolerance test was used to assess glucose tolerance (2-h glucose) , insulin sensitivity (Matsuda Index) , and β-cell function (oral disposition index, oDI) at baseline, 6 months, and 12 months. Changes in outcomes were analyzed using latent difference scores models. Results: The INT led to significant decreases in 2-h glucose (mean±SE, from 144.5±3.4 to 132.2±3.4 mg/dL, p=0.002) and increases in insulin sensitivity (from 1.9±0.2 to 2.6±0.3, p=0.001) and oDI (from 4.5±0.3 to 5.5±0.4, p=0.035) at 6 months, but these changes were not significantly different from UC (interaction, p=0.260, p=0.79, and p=0.78, respectively) . Both INT (-15.4 mg/dL, p=0.002) and UC (-15.1 mg/dL, p=0.005) had significant 12-month reductions in 2-h glucose that did not differ significantly from each other (interaction, p=0.97) . INT led to significant increases in oDI (from 4.5±0.3 to 6.2±0.6, p=0.035) and non-significant increases in insulin sensitivity (from 1.9±0.2 to 2.3±0.2, p=0.060) at 12 months that did not differ from UC (interaction, p=0.66 and p=0.37, respectively) . Conclusion: Both INT and UC led to similar changes in T2D risk factors among high risk Latino youth. Diabetes prevention interventions that are effective in adults also appear to be effective in high risk youth. Disclosure A. Pena: None. M. Olson: None. S. Ayers: None. D.L. Patrick: Consultant; Allakos, Bristol-Myers Squibb Company, Grail, Philip Morris. F.G. Castro: None. E. Lish: None. W.C. Knowler: None. G.Q. Shaibi: None. Funding R01DK107579F31DK125037

Insulin secretion and sensitivity regulate glycemia, with inadequately compensated deficiencies in either or both leading to diabetes. Using data from 2931 participants in the DPP repository, we investigate the effects of lifestyle and metformin interventions and of weight loss on the relationship between insulin secretion and sensitivity. Insulin secretion and sensitivity were estimated from insulin concentrations in fasting and 30-minute post-load serum samples at baseline and at 1, 2, and 3 years after randomization during the active intervention phase of the DPP. The relationship of secretion and sensitivity was evaluated by standardized major axis regression and was found to change over time for participants in the lifestyle and metformin interventions. Distances along and away from the regression line were taken to characterize insulin secretory demand and insulin secretion in compensation to the demand, respectively. Both the metformin and lifestyle interventions decreased secretory demand while increasing compensatory insulin secretion, with greater effects of the lifestyle intervention. Improvements were directly related to the amount of weight loss; decreases in weight significantly reduced secretory demand [b=-0.088 SD (-0.102, -0.074) /5 kg loss] and increased compensatory insulin secretion [b=0.169 SD (0.149, 0.189) /5 kg loss]. In time-dependent hazard models, increasing secretory demand associated with increased diabetes risk [hazard ratio (HR) =1.189 per baseline SD (1.004, 1.413) ] while increasing compensatory insulin secretion associated with lower risk [HR=0.1 (0.080, 0.145) ]. These results are consistent with earlier observations in the DPP that diabetes risk reduction was directly related to the amount of weight loss and suggest that this effect is mediated by lowered insulin secretory demand coupled with improved compensatory insulin secretion. Disclosure W.C. Knowler: None. R.L. Hanson: None.

Introduction: Lifestyle intervention is a cost-effective approach for preventing type 2 diabetes among adults with prediabetes. Little is known about the cost effectiveness of lifestyle programs for children with prediabetes. The purpose of this study was to examine the cost and incremental cost effectiveness of an adapted diabetes prevention intervention compared to usual care among Latino youth with prediabetes. Methods: Latino youth (age 13.5±1.4 years, mean±SD) with obesity and prediabetes were randomized to a community-based lifestyle intervention (INT, N=79) or usual care (UC, N=38) . The 6-month INT was delivered at a YMCA and included 1 d/wk of lifestyle education for families and 3 d/wk of physical activity. UC included 2 visits with a pediatric endocrinologist and registered dietician to discuss diabetes risks and healthy lifestyle changes. Data on health care costs and resource utilization were collected prospectively. Efficacy was examined as changes in 2-hr glucose concentrations during an OGTT. Cost analyses were performed from health care sector and societal perspectives. Results: The INT led to decreases in 2-hr glucose (144.5±3.4 to 132.2±3.4 mg/dL, p=0.002) but these changes were not significantly different from changes in 2-hr glucose observed in UC participants (144.1±4.6 to 139.0±4.6; interaction p=0.260) . The average health care costs per participant were $1,032 for the INT and $1,251 for the UC. Total societal costs (health care plus patient and family opportunity costs) per participant were $3,641 for the INT and $1,331 for the UC. For health care costs alone, the incremental cost-effectiveness ratio (ICER) for 2-hr glucose was -$30.3 per mg/dL. When taking total costs into account, the ICER for 2-hr glucose was $320.8 per mg/dL. Conclusion: From a health care sector perspective, INT led to greater reductions in 2-hr glucose at a lower cost compared to UC among Latino youth with prediabetes. The cost-effectiveness of INT decreases when total societal costs are included. Disclosure M.Olson: None. A.Pena: None. M.E.Putz: None. S.Ayers: None. W.C.Knowler: None. M.Mccullough: None. G.Q.Shaibi: None. Funding National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Disease (R01DK10757901)

Polygenic scores (PS) for type 2 diabetes (T2D) associate strongly with disease status. Since T2D is heterogenous, using “partitioned” PS (pPS) that capture distinct etiological processes may improve clinical utility. A previous study in Europeans identified 6 pPS from genetic clusters (GCs) based on association patterns across traits, among 3T2D-associated variants: adiposity (GC1) , lipids (GC2) , insulin action (GC3) , beta cell function (GC4, GC5) , and mixed features (GC6) . Few data exist on how pPS associate with T2D and subphenotypes in non-European populations. The current analysis reconstructed these pPS using genotypes for 245 of the 3variants captured in a genome-wide association study in an Indigenous study population from the Southwest US. pPS associations were analyzed with T2D (N=7659) , % body fat (PFAT, non-diabetic only, n=557) , insulin action from hyperinsulinemic-euglycemic “clamp” (logM, non-diabetic only, n=557) , and acute insulin response from an IVGTT (lgAIR, normal glucose tolerance only, n=404) . Results (table) show that T2D pPS strongly associate with the subphenotype corresponding to the putative etiologic mechanism. These results demonstrate transferability of the phenotypic classifications of the T2D pPS and suggest that genetic influences on adiposity, insulin action, and insulin secretion contribute to development of T2D in this population. Disclosure L.E.Wedekind: None. W.Hsueh: None. S.Kobes: None. L.Baier: None. C.Bogardus: None. W.C.Knowler: None. A.Mahajan: Employee; Genentech, Inc. M.Mccarthy: Employee; Genentech, Inc. R.L.Hanson: None.

Context Observational studies suggest that low vitamin D status may be a risk factor for cancer. Objective In a population with prediabetes and overweight/obesity that is at higher risk of cancer than the general population, we sought to determine if vitamin D supplementation lowers the risk of cancer and precancers. Methods The Vitamin D and type 2 diabetes (D2d) cancer outcomes study (D2dCA) is an ancillary study to the D2d study, which was conducted at 22 academic medical centers in the United States. Participants had prediabetes and overweight/obesity and were free of cancer for the previous 5 years. Participants were randomized to receive vitamin D3 4000 IU daily or placebo. At scheduled study visits (4 times/year), cancer and precancer events were identified by questionnaires. Clinical data were collected and adjudicated for all reported events. Cox proportional hazard models compared the hazard ratio (HR) of incident cancers and precancers between groups. Results Over a median follow-up period of 2.9 years, among 2385 participants (mean age 60 years and 25-hydroxyvitamin D 28 ng/mL), there were 89 cases of cancer. The HR of incident cancer for vitamin D vs placebo was 1.07 (95% CI 0.70, 1.62). Of 241 participants with incident precancers, 239 had colorectal adenomatous polyps. The HR for colorectal polyps for vitamin D vs placebo was 0.83 (95% CI 0.64, 1.07). Conclusion In the D2d population of participants with prediabetes and overweight/obesity, not selected for vitamin D insufficiency, vitamin D supplementation did not have a significant effect on risk of incident cancer or colorectal polyps.

OBJECTIVE: To determine whether interventions that slow or prevent the development of type 2 diabetes mellitus in those at risk reduce the subsequent prevalence of diabetic retinopathy. RESEARCH DESIGN AND METHODS: The Diabetes Prevention Program (DPP) randomized subjects at risk for developing type 2 diabetes because of overweight/obesity and dysglycemia to either metformin (MET), intensive lifestyle intervention (ILS) or placebo (PLB) to assess the prevention of diabetes. During the DPP and DPP Outcome Study (DPPOS), we performed fundus photography over time on study participants, regardless of their diabetes status. Fundus photographs were graded using the ETDRS grading system with diabetic retinopathy defined as typical lesions of diabetic retinopathy (microaneurysms, exudates or hemorrhage, or worse) in either eye. RESULTS: Despite reduced progression to diabetes in the ILS and MET groups compared to PLB, there was no difference in the prevalence of diabetic retinopathy between treatment groups after 1, 5, 11 or 16 years of follow up. No treatment group differences in retinopathy were found within prespecified subgroups (baseline age, sex, race/ethnicity, baseline BMI). In addition, there was no difference in the prevalence of diabetic retinopathy between those exposed to metformin and those not exposed to metformin regardless of treatment group assignment. CONCLUSION: Interventions that delay or prevent the onset of type 2 diabetes in overweight/obese subjects with dysglycemia who are at risk for diabetes do not reduce the development of diabetic retinopathy for up to 20 years.

OBJECTIVE To determine glycemic and nonglycemic risk factors that contribute to the presence of diabetic retinopathy (DR) before and after the onset of type 2 diabetes (T2D). RESEARCH DESIGN AND METHODS During the Diabetes Prevention Program (DPP) and DPP Outcome Study (DPPOS), we performed fundus photography over time in adults at high risk for developing T2D, including after they developed diabetes. Fundus photographs were graded using the Early Treatment Diabetic Retinopathy Study (ETDRS) grading system, with DR defined as typical lesions of DR (microaneurysms, exudates, hemorrhage, or worse) in either eye. RESULTS By DPPOS year 16 (∼20 years after random assignment into DPP), 24% of 1,614 participants who had developed T2D and 14% of 885 who remained without diabetes had DR. In univariate analyses, using results from across the entire duration of follow-up, American Indian race was associated with less frequent DR compared with non-Hispanic White (NHW) race, and higher HbA1c, fasting and 2-h plasma glucose levels during an oral glucose tolerance test, weight, and history of hypertension, dyslipidemia, and smoking, but not treatment group assignment, were associated with more frequent DR. On multivariate analysis, American Indian race was associated with less DR compared with NHW (odds ratio [OR] 0.36, 95% CI 0.20–0.66), and average HbA1c was associated with more DR (OR 1.92, 95% CI 1.46–1.74 per SD [0.7%] increase in HbA1c). CONCLUSIONS DR may occur in adults with prediabetes and early in the course of T2D. HbA1c was an important risk factor for the development of DR across the entire glycemic range from prediabetes to T2D.

Objective. Patients with type 2 diabetes are encouraged to lose weight, but excessive weight loss in older adults may be a marker of poor health and subsequent mortality. We examined weight changes during the post-intervention period of Look AHEAD, a randomized trial comparing intensive lifestyle intervention (ILI) and diabetes support and education (DSE; control) in individuals with overweight/obesity and type 2 diabetes and sought to identify predictors of excessive post-intervention weight loss and its association with mortality. Research Design and Methods. These secondary analyses compared post-intervention weight change (year-8 to final visit [median 16 years]) in ILI and DSE in 3999 Look AHEAD participants. Using empirically derived trajectory categories, we compared four subgroups: Weight Gainers (N= 307), Weight Stable (N=1561), Steady Losers (N=1731) and Steep Losers (N=380) on post-intervention mortality, demographic variables and health status at randomization and year-8. Results. Post-intervention weight change averaged -3.7 ±9.5%, with greater weight loss in DSE than ILI. The steep weight loss trajectory subgroup lost on average 17.7 + 6.6%.; 30% of Steep Losers died during post-intervention follow-up vs 10-18% in other trajectories (pBaseline - older; longer diabetes duration; higher BMI; greater multimorbidity; Intervention – randomization to control group; less weight loss in years 1-8; Year 8 - higher prevalence of frailty, multimorbidity and depressive symptoms; lower use of weight control strategies. Conclusion. Steep weight losses post-intervention were associated with increased risk of mortality. Older individuals with longer duration diabetes and multi-morbidity should be monitored for excessive, unintentional weight loss.

Background Among patients with type 2 diabetes, minority racial/ethnic groups have a higher burden of cardiovascular disease, chronic kidney disease, and hypoglycaemia. These groups may especially benefit from newer diabetes medication classes, but high cost may limit access. We examined the association of race/ethnicity with the initiation of newer diabetes medications (GLP-1 receptor agonists, DPP-4 inhibitors, SGLT-2 inhibitors). Methods We conducted a secondary analysis of the Look AHEAD (Action for Health in Diabetes) trial including participants with at least one study visit after April 28, 2005. Cox proportional hazards models were used to estimate the association between race/ethnicity and socioeconomic factors with time to initiation of any newer diabetes medication from April 2005 to February 2020. Models were adjusted for demographic and clinical characteristics. Findings Among 4,892 participants, 63.6%, 15.7%, 12.6%, 5.2%, and 2.9% were White, Black, Hispanic, American Indian or Alaskan Native (AI/AN), or other race/ethnicity, respectively. During a median follow-up of 8.3 years, 2,180 (45.2%) participants were initiated on newer diabetes medications. Race/ethnicity was associated with newer diabetes medication initiation (p=.019). Specifically, initiation was lower among Black (HR 0.81, 95% CI 0.70–0.94) and AI/AN participants (HR 0.51, 95% CI 0.26–0.99). Yearly family income was inversely associated with initiation of newer diabetes medications (HR 0.78, 95% CI 0.62–0.98) comparing the lowest and highest income groups. Findings were mostly driven by GLP-1 receptor agonists. Interpretation These findings provide evidence of racial/ethnic disparities in the initiation of newer diabetes medications, independent of socioeconomic factors, which may contribute to worse health outcomes. Funding source NIDDK, NIH

OBJECTIVE Across the Diabetes Prevention Program (DPP) follow-up, cumulative diabetes incidence remained lower in the lifestyle compared with the placebo and metformin randomized groups and could not be explained by weight. Collection of self-reported physical activity (PA) (yearly) with cross-sectional objective PA (in follow-up) allowed for examination of PA and its long-term impact on diabetes prevention. RESEARCH DESIGN AND METHODS Yearly self-reported PA and diabetes assessment and oral glucose tolerance test results (fasting glucose semiannually) were collected for 3,232 participants with one accelerometry assessment 11–13 years after randomization (n = 1,793). Mixed models determined PA differences across treatment groups. The association between PA and diabetes incidence was examined using Cox proportional hazards models. RESULTS There was a 6% decrease (Cox proportional hazard ratio 0.94 [95% CI 0.92, 0.96]; P < 0.001) in diabetes incidence per 6 MET-h/week increase in time-dependent PA for the entire cohort over an average of 12 years (controlled for age, sex, baseline PA, and weight). The effect of PA was greater (12% decrease) among participants less active at baseline ( CONCLUSIONS PA was inversely related to incident diabetes in the entire cohort across the study, with cross-sectional accelerometry results supporting these findings. This highlights the importance of PA within lifestyle intervention efforts designed to prevent diabetes and urges health care providers to consider both PA and weight when counseling high-risk patients.

OBJECTIVE Postrandomization biases may influence the estimate of efficacy of supplemental vitamin D in diabetes prevention trials. In the Vitamin D and Type 2 Diabetes (D2d) study, repeated measures of serum 25-hydroxyvitamin D [25(OH)D] level provided an opportunity to test whether intratrial vitamin D exposure affected diabetes risk and whether the effect was modified by trial assignment (vitamin D vs. placebo). RESEARCH DESIGN AND METHODS The D2d study compared the effect of daily supplementation with 100 μg (4,000 units) of vitamin D3 versus placebo on new-onset diabetes in adults with prediabetes. Intratrial vitamin D exposure was calculated as the cumulative rolling mean of annual serum 25(OH)D measurements. Hazard ratios for diabetes among participants who had intratrial 25(OH)D levels of RESULTS There was an interaction of trial assignment with intratrial 25(OH)D level in predicting diabetes risk (interaction P = 0.018). The hazard ratio for diabetes for an increase of 25 nmol/L in intratrial 25(OH)D level was 0.75 (95% CI 0.68–0.82) among those assigned to vitamin D and 0.90 (0.80–1.02) among those assigned to placebo. The hazard ratios for diabetes among participants treated with vitamin D who maintained intratrial 25(OH)D levels of 100–124 and ≥125 nmol/L were 0.48 (0.29–0.80) and 0.29 (0.17–0.50), respectively, compared with those who maintained a level of 50–74 nmol/L. CONCLUSIONS Daily vitamin D supplementation to maintain a serum 25(OH)D level ≥100 nmol/L is a promising approach to reducing the risk of diabetes in adults with prediabetes.

AIMS/HYPOTHESIS: Prevalence of type 2 diabetes differs among human ancestry groups, and many hypotheses invoke differential natural selection to account for these differences. We sought to assess the potential role of differential natural selection across major continental ancestry groups for diabetes and related traits, by comparison of genetic and phenotypic differences. METHODS: This was a cross-sectional comparison among 734 individuals from an urban sample (none of whom was more closely related to another than third-degree relatives), including 83 African Americans, 523 American Indians and 128 European Americans. Participants were not recruited based on diabetes status or other traits. BMI was calculated, and diabetes was diagnosed by a 75 g oral glucose tolerance test. In those with normal glucose tolerance (n=434), fasting insulin and 30 min post-load insulin, adjusted for 30 min glucose, were taken as measures of insulin resistance and secretion, respectively. Whole exome sequencing was performed, resulting in 97,388 common (minor allele frequency >5%) variants; the coancestry coefficient (F(ST)) was calculated across all markers as a measure of genetic divergence among ancestry groups. The phenotypic divergence index (P(ST)) was also calculated from the phenotypic differences and heritability (which was estimated from genetic relatedness calculated empirically across all markers in 761 American Indian participants prior to the exclusion of close relatives). Under evolutionary neutrality, the expectation is P(ST)=F(ST), while for traits under differential selection P(ST) is expected to be significantly greater than F(ST.) A bootstrap procedure was used to test the hypothesis P(ST)=F(ST.) RESULTS: With adjustment for age and sex, prevalence of type 2 diabetes was 34.0% in American Indians, 12.4% in African Americans and 10.4% in European Americans (p=2.9×10(−10) for difference among groups). Mean BMI was 36.3, 33.4 and 33.0 kg/m(2), respectively (p=1.9×10(−7)). Mean fasting insulin was 63.8, 48.4 and 45.2 pmol/l (p=9.2×10(−5)), while mean 30 min insulin was 559.8, 553.5 and 358.8 pmol/l, respectively (p=5.7×10(−8)). F(ST) across all markers was 0.130, while P(ST) for liability to diabetes, adjusted for age and sex, was 0.149 (p=0.35 for difference with F(ST)). P(ST) was 0.094 for BMI (p=0.54), 0.095 for fasting insulin (p=0.54) and 0.216 (p=0.18) for 30 min insulin. For type 2 diabetes and BMI, the maximum divergence between populations was observed between American Indians and European Americans (P(ST-MAX)=0.22, p=0.37, and P(ST-MAX)=0.14, p=0.61), which suggests that a relatively modest 22% or 14% of the genetic variance, respectively, can potentially be explained by differential selection (assuming the absence of neutral drift). CONCLUSIONS/INTERPRETATION: These analyses suggest that while type 2 diabetes and related traits differ significantly among continental ancestry groups, the differences are consistent with neutral expectations based on heritability and genetic distances. While these analyses do not exclude a modest role for natural selection, they do not support the hypothesis that differential natural selection is necessary to explain the phenotypic differences among these ancestry groups.

Objective This study was designed to determine whether intensive lifestyle intervention (ILI) aimed at weight loss lowers cancer incidence and mortality. Methods Data from the Look AHEAD trial were examined to investigate whether participants randomized to ILI designed for weight loss would have reduced overall cancer incidence, obesity-related cancer incidence, and cancer mortality, as compared with the diabetes support and education (DSE) comparison group. This analysis included 4,859 participants without a cancer diagnosis at baseline except for nonmelanoma skin cancer. Results After a median follow-up of 11 years, 684 participants (332 in ILI and 352 in DSE) were diagnosed with cancer. The incidence rates of obesity-related cancers were 6.1 and 7.3 per 1,000 person-years in ILI and DSE, respectively, with a hazard ratio (HR) of 0.84 (95% CI: 0.68-1.04). There was no significant difference between the two groups in total cancer incidence (HR, 0.93; 95% CI: 0.80-1.08), incidence of nonobesity-related cancers (HR, 1.02; 95% CI: 0.83-1.27), or total cancer mortality (HR, 0.92; 95% CI: 0.68-1.25). Conclusions An ILI aimed at weight loss lowered incidence of obesity-related cancers by 16% in adults with overweight or obesity and type 2 diabetes. The study sample size likely lacked power to determine effect sizes of this magnitude and smaller.

Applying exome sequencing to populations with unique genetic architecture has the potential to reveal novel genes and variants associated with traits and diseases. We sequenced and analyzed the exomes of 6,716 individuals from a Southwestern American Indian (SWAI) population with well-characterized metabolic traits. We found that the SWAI population has distinct allelic architecture compared to populations of European and East Asian ancestry, and there were many predicted loss-of-function (pLOF) and nonsynonymous variants that were highly enriched or private in the SWAI population. We used pLOF and nonsynonymous variants in the SWAI population to evaluate gene-burden associations of candidate genes from European genome-wide association studies (GWASs) for type 2 diabetes, body mass index, and four major plasma lipids. We found 19 significant gene-burden associations for 11 genes, providing additional evidence for prioritizing candidate effector genes of GWAS signals. Interestingly, these associations were mainly driven by pLOF and nonsynonymous variants that are unique or highly enriched in the SWAI population. Particularly, we found four pLOF or nonsynonymous variants in APOB, APOE, PCSK9, and TM6SF2 that are private or enriched in the SWAI population and associated with low-density lipoprotein (LDL) cholesterol levels. Their large estimated effects on LDL cholesterol levels suggest strong impacts on protein function and potential clinical implications of these variants in cardiovascular health. In summary, our study illustrates the utility and potential of exome sequencing in genetically unique populations, such as the SWAI population, to prioritize candidate effector genes within GWAS loci and to find additional variants in known disease genes with potential clinical impact.

AIMS: To examine the associations of average weight and weight velocity in three growth periods from birth through adolescence with type 2 diabetes incidence. METHODS: Child participants representing three growth periods- pre-adolescence (birth to ~8 years), early adolescence (~8 to ~13 years), and late adolescence (~13 to ~18 years) -were selected from a 43-year longitudinal study of American Indians. Age-sex-height-standardized average weight z score and weight z score velocity (change/year) were computed in each period. Participants were followed for up to 25 years from the end of each growth period until they developed diabetes. Associations of average weight z score or weight z score velocity with diabetes incidence were determined with sex-, birth date- and maternal diabetes-adjusted Poisson regression models. RESULTS: Among 2,100 participants representing the pre-adolescence growth period, 1,558 representing the early adolescence period, and 1,418 representing the late adolescence period, there were 290, 315, and 380 incident diabetes cases, respectively. During the first 10 years of follow-up, diabetes incidence rate ratio was 1.72 (95% CI 1.40–2.11)/standard deviation (SD) of log(10)weight z score mean in pre-adolescence, 2.09 (1.68–2.60)/SD of log(10)weight z score mean in early adolescence, and 1.85 (1.58–2.17)/SD of log(10)weight z score mean in late adolescence. Diabetes incidence rate ratio was 1.79 (1.49–2.17)/SD of log(10)weight z score velocity pre-adolescence, 1.13 (0.91–1.41)/SD log(10)weight z score velocity in early adolescence, and 1.29 (1.09–1.51)/SD log(10)weight z score velocity in late adolescence. There were strong correlations in the average weight z scores and weak correlations in the weight z score velocities between successive periods. CONCLUSIONS: Higher weight and accelerated weight gain in all growth periods associates with increased type 2 diabetes risk. Importantly, higher weight and greater weight velocity pre-adolescence jointly associate with the highest type 2 diabetes risk.

Objective: This study evaluated weight changes after cessation of the 10-year intensive lifestyle intervention (ILI) in the Look AHEAD (Action for Health in Diabetes) study. It was hypothesized that ILI participants would be more likely to gain weight during the 2-year observational period following termination of weight-loss-maintenance counseling than would participants in the diabetes support and education (DSE) control group. Methods: Look AHEAD was a randomized controlled trial that compared the effects of ILI and DSE on cardiovascular morbidity and mortality in participants with overweight/obesity and type 2 diabetes. Look AHEAD was converted to an observational study in September 2012. Results: Two years after the end of the intervention (EOI), ILI and DSE participants lost a mean (SE) of 1.2 (0.2) kg and 1.8 (0.2) kg, respectively (P = 0.003). In addition, 31% of ILI and 23.9% of DSE participants gained ≥ 2% (P < 0.001) of EOI weight, whereas 36.3% and 45.9% of the respective groups lost ≥ 2% of EOI weight (P = 0.001). Two years after the EOI, ILI participants reported greater use of weight-control behaviors than DSE participants. Conclusions: Both groups lost weight during the 2-year follow-up period, but more ILI than DSE participants gained ≥ 2% of EOI weight. Further understanding is needed of factors that affected long-term weight change in both groups.

Objective Fasting plasma glucose (FPG), 2-hour plasma glucose (2hPG) from a 75-g oral glucose tolerance test (OGTT) and glycated hemoglobin (HbA1c) can lead to different results when diagnosing prediabetes and diabetes. The Hemoglobin Glycation Index (HGI) quantifies the interindividual variation in glycation resulting in discrepancies between FPG and HbA1c. We used data from the Vitamin D and Type 2 Diabetes (D2d) study to calculate HGI, to identify HGI-associated variables, and to determine how HGI affects prediabetes and diabetes diagnosis. Measurements A linear regression equation [HbA1c (%) = 0.0164 × FPG (mg/dL) + 4.2] was derived using the screening cohort (n = 6829) and applied to calculate predicted HbA1c. This was subtracted from the observed HbA1c to determine HGI in the baseline cohort with 2hPG data (n = 3945). Baseline variables plus prediabetes and diabetes diagnosis by FPG, HbA1c, and 2hPG were compared among low, moderate, and high HGI subgroups. Results The proportion of women and Black/African American individuals increased from low to high HGI subgroups. Mean FPG decreased and mean HbA1c increased from low to high HGI subgroups, consistent with the HGI calculation; however, mean 2hPG was not significantly different among HGI subgroups. Conclusions High HGI was associated with Black race and female sex as reported previously. The observation that 2hPG was not different across HGI subgroups suggests that variation in postprandial glucose is not a significant source of population variation in HGI. Exclusive use of HbA1c for diagnosis will classify more Black individuals and women as having prediabetes compared with using FPG or 2hPG.

Objective The extent to which infertility and pregnancy independently increase risk of diabetes and subclinical atherosclerosis is not known. Research Design And Methods We conducted a secondary analysis of Diabetes Prevention Program (DPP) and the DPP Outcomes Study over a 15-year period. We included women who answered questions about gravidity and infertility at baseline (n = 2085). Infertility was defined as > 1 year of unsuccessful attempts to conceive; thus, women could have histories of infertility as well as pregnancy. Risk of diabetes associated with gravidity and infertility was calculated using Cox proportional hazards models adjusting for age, race/ethnicity, treatment arm, body mass index, and pregnancy during the study. Among women who underwent assessment of coronary artery calcification (CAC) (n = 1337), odds of CAC were calculated using logistic regression models with similar covariates. Results Among premenopausal women (n = 1075), women with histories of pregnancy and infertility (n = 147; hazard ratio [HR] 1.80; 95% confidence interval [CI] 1.30, 2.49) and women with histories of pregnancy without infertility (n = 736; HR 1.49; 95% CI 1.15, 1.93) had greater diabetes risk than nulligravid women without infertility (n = 173). Premenopausal nulligravid women with histories of infertility had a non-significant elevation in risk, although the number of these women was small (n = 19; HR 1.63; 95% CI 0.88, 3.03). Associations were not observed among postmenopausal women (n = 1010). No associations were observed between infertility or pregnancy with CAC. Conclusions Pregnancy, particularly combined with a history of infertility, confers increased risk of diabetes but not CAC among glucose-intolerant premenopausal women.

Objective To examine the effects of an intensive lifestyle intervention (ILI) on cardiovascular disease (CVD), the Action for Health in Diabetes (Look AHEAD) trial randomized 5,145 participants with type 2 diabetes and overweight/obesity to a ILI or diabetes support and education. Although the primary outcome did not differ between the groups, there was suggestive evidence of heterogeneity for prespecified baseline CVD history subgroups (interaction P = 0.063). Event rates were higher in the ILI group among those with a CVD history (hazard ratio 1.13 [95% CI: 0.90-1.41]) and lower among those without CVD (hazard ratio 0.86 [95% CI: 0.72-1.02]). Methods This study conducted post hoc analyses of the rates of the primary composite outcome and components, adjudicated cardiovascular death, nonfatal myocardial infarction (MI), stroke, and hospitalization for angina, as well as three secondary composite cardiovascular outcomes. Results Interaction P values for the primary and two secondary composites were similar (0.060-0.064). Of components, the interaction was significant for nonfatal MI (P = 0.035). This interaction was not due to confounding by baseline variables, different intervention responses for weight loss and physical fitness, or hypoglycemic events. In those with a CVD history, statin use was high and similar by group. In those without a CVD history, low-density lipoprotein cholesterol levels were higher (P = 0.003) and statin use was lower (P ≤ 0.001) in the ILI group. Conclusions Intervention response heterogeneity was significant for nonfatal MI. Response heterogeneity may need consideration in a CVD-outcome trial design.

Purpose To compare Early Treatment Diabetic Retinopathy Study (ETDRS) severity levels between two digital fundus imaging protocols for research studies of diabetic retinopathy: the gold standard 7-field (7F) imaging and the more recent 4-widefield (4W) imaging. Methods Two hundred twenty-two participants enrolled in the Diabetes Prevention Program Outcomes Study underwent concurrent 7F and 4W imaging. The ETDRS levels from 220 paired gradable images were determined by masked graders. Each image was graded by two independent graders with adjudication by a senior grader, if necessary. Percent agreement between graders and between imaging protocols was evaluated with kappa statistics and weighted kappa statistics. Results Of 220 gradable eyes, diabetic retinopathy was seen in 11.8%; this was mild in 10.4% and more than mild in 1.4% using 7F imaging. The ETDRS levels showed exact agreement of 95% between 7F and 4W imaging (weighted kappa 0.86). Intergrader agreement for each modality had exact agreement of 89% (weighted kappa of 0.73) for 7F and 91% (weighted kappa 0.77) for 4W. Conclusions There is substantial agreement in the ETDRS severity level between the 7F and 4W digital imaging protocols, demonstrating that the two imaging protocols are interchangeable. Both 4W and 7F digital imaging protocols can be used for assessing ETDRS levels, even in populations with minimal diabetic retinopathy. Translational Relevance The 4W protocol requires fewer images than the 7F, is more comfortable for the patients, is easier for photographic capture, and provides diabetic retinopathy data that is equivalent to the 7F imaging protocol.

The Pima Indians of the Gila River Indian Community in Arizona have participated in a long-range study of type 2 diabetes mellitus since 1965 and have been the subject of HLA typing and population studies since the early days of serological assays. These data have been in numerous HLA workshops and conferences and have been the source of at least five novel alleles at the classical HLA loci. In recent time nearly the entire study group was subject to next generation sequencing by whole genome or exome technologies, which has allowed us to HLA type over 3000 full heritage persons with recently developed computer algorithms. We present here the results for the classical HLA Loci: HLA-A, B, C, DRA, DRB1, DRB3, DRB4, DRB5, DPA1, DPB1, DQA1, and DQB1 to the third field of resolution for synonymous alleles and type the likely four field resolution alleles from the subset of whole genome sequences. Allele frequencies, and haplotype frequencies at up to five loci, are presented as well as measures of population structure and heterozygosity. We define a core set of HLA variation that approximates the distribution for the Paleo-Indians and impute nine-locus, 4-field haplotypes that are expected to be common in full heritage peoples.