The islet tissue plasminogen activator/plasmin system is upregulated with human islet amyloid polypeptide aggregation and protects beta cells from aggregation-induced toxicity.

AIMS/HYPOTHESIS: Apart from its fibrinolytic activity, the tissue plasminogen activator (tPA)/plasmin system has been reported to cleave the peptide amyloid beta, attenuating brain amyloid deposition in Alzheimer's disease. As aggregation of human islet amyloid polypeptide (hIAPP) is toxic to beta cells, we sought to determine whether activation of the fibrinolytic system can also reduce islet amyloid deposition and its cytotoxic effects, which are both observed in type 2 diabetes. METHODS: The expression of Plat (encoding tPA) and plasmin activity were measured in isolated islets from amyloid-prone hIAPP transgenic mice or non-transgenic control islets expressing non-amyloidogenic mouse islet amyloid polypeptide cultured in the absence or presence of the amyloid inhibitor Congo Red. Plat expression was also determined in hIAPP-treated primary islet endothelial cells, bone marrow-derived macrophages (BMDM) and INS-1 cells, in order to determine the islet cell type(s) producing tPA in response to hIAPP aggregation. Cell-free thioflavin-T assays and MS were used to respectively monitor hIAPP aggregation kinetics and investigate plasmin cleavage of hIAPP. Cell viability was assessed in INS-1 beta cells treated with hIAPP with or without plasmin. Finally, to confirm the findings in human samples, PLAT expression was measured in freshly isolated islets from donors with and without type 2 diabetes. RESULTS: In isolated islets from transgenic mice, islet Plat expression and plasmin activity increased significantly with the process of amyloid deposition (p≤0.01, n=5); these effects were not observed in islets from non-transgenic mice and were blocked by Congo Red (p≤0.01, n=4). In response to hIAPP exposure, Plat expression increased in BMDM and INS-1 cells vs vehicle-treated cells (p≤0.05, n=4), but not in islet endothelial cells. Plasmin reduced hIAPP fibril formation in a dose-dependent manner in a cell-free system, and restored hIAPP-induced loss of cell viability in INS-1 beta cells (p≤0.01, n=5). Plasmin cleaved monomeric hIAPP, inducing a rapid decrease in the abundance of full-length hIAPP and the appearance of hIAPP 1-11 and 12-37 fragments. hIAPP 12-37, which contains the critical amyloidogenic region, was not toxic to INS-1 cells. Finally, PLAT expression was significantly increased by 2.4-fold in islets from donors with type 2 diabetes (n=4) vs islets from donors without type 2 diabetes (n=7) (p≤0.05). CONCLUSIONS/INTERPRETATION: The fibrinolytic system is upregulated in islets with hIAPP aggregation. Plasmin rapidly degrades hIAPP, limiting its aggregation into amyloid and thus protecting beta cells from hIAPP-induced toxicity. Thus, increasing islet plasmin activity might be a strategy to limit beta cell loss in type 2 diabetes.

Abdominal visceral-to-subcutaneous fat ratio in the prediction of metabolic syndrome risk in Japanese Americans followed prospectively for 10-years loses information.

AIMS: Visceral fat predicts the development of metabolic syndrome (MetS), but it is not known whether the visceral to subcutaneous fat area ratio (VSR) measured using imaging predicts MetS risk as well or better. Thus, we aimed to examine if VSR predicted future risk of MetS over 10-years. METHODS: We followed 329 participants in the longitudinal Japanese American Community Diabetes Study without MetS at baseline for its development over 10 years. Intra-abdominal (VFA) and subcutaneous abdominal (SFA) fat areas were measured at baseline and 10-years and used to calculate VSR. Logistic regression was used to estimate the odds of incident MetS by baseline and 10-year change in VSR and other adipose depots with and without adjustment for baseline MetS features. Areas under ROC curves were calculated in predicting the development of MetS. RESULTS: 99 participants developed MetS over 10-years. Logistic regression models showed a higher odds of incident MetS with greater VSR and 10-year VSR change (OR = 1.67, 95 % CI 1.11-2.51; OR = 1.46, 95 % CI 1.06-2.01, respectively) adjusting for age, sex, and MetS features at baseline. However, VSR alone performed poorly at discriminating (AUROC 0.5807) compared to VFA (AUROC 0.6970, p < 0.001) or a logistic model incorporating VFA and SFA (AUROC 0.7221, p = 0.001). CONCLUSIONS: VSR and VFA predict 10-year MetS risk in Japanese Americans, confirming the importance of relatively greater fat distribution in the visceral depot in the development of MetS. However, VSR is a weaker predictor of MetS development and provides less information compared to VFA alone, and its further use in predicting metabolic abnormalities is not recommended.

Semaglutide versus placebo in patients with heart failure and mildly reduced or preserved ejection fraction: a pooled analysis of the SELECT, FLOW, STEP-HFpEF, and STEP-HFpEF DM randomised trials.

BACKGROUND: Heart failure with mildly reduced or preserved ejection fraction (hereafter referred to as HFpEF) is the most common type of heart failure and is associated with a high risk of hospitalisation and death, especially in patients with overweight, obesity, or type 2 diabetes. In the STEP-HFpEF and STEP-HFpEF DM trials, semaglutide improved heart failure-related symptoms and physical limitations in participants with HFpEF. Whether semaglutide also reduces clinical heart failure events in this group remains to be established. METHODS: We conducted a post-hoc pooled, participant-level analysis of four randomised, placebo-controlled trials (SELECT, FLOW, STEP-HFpEF, and STEP-HFpEF DM) to examine the effects of once-weekly subcutaneous semaglutide (2·4 mg in SELECT, STEP-HFpEF, and STEP-HFpEF DM; 1·0 mg in FLOW) on heart failure events. The STEP-HFpEF and STEP-HFpF DM trials enrolled participants with obesity-related HFpEF, the SELECT trial enrolled participants with atherosclerotic cardiovascular disease and overweight or obesity, and the FLOW trial enrolled participants with type 2 diabetes and chronic kidney disease. Hence, for this analysis, we include all participants from the STEP-HFpEF trials and those with an investigator-reported history of HFpEF from SELECT and FLOW. The main outcomes for this analysis were the composite endpoint of time to cardiovascular death or first worsening heart failure event (defined as hospitalisation or urgent visit due to heart failure), time to first worsening heart failure event, and time to cardiovascular death. Efficacy and safety endpoints were analysed with the full analysis set (ie, all participants randomly assigned to treatment, according to the intention-to-treat principle). The SELECT, FLOW, STEP-HFpEF, and STEP-HFpEF DM trials are registered at ClinicalTrials.gov, NCT03574597, NCT03819153, NCT04788511, and NCT04916470, respectively, and all are complete. FINDINGS: Across the four trials, 3743 (16·8%) of 22 282 participants had a history of HFpEF (1914 assigned to semaglutide and 1829 assigned to placebo). In this group of participants with HFpEF, semaglutide reduced the risk of the combined endpoint of cardiovascular death or heart failure events (103 [5·4%] of 1914 in the semaglutide group had events vs 138 [7·5%] of 1829 in the placebo group; hazard ratio [HR] 0·69 [95% CI 0·53-0·89]; p=0·0045). Semaglutide also reduced the risk of worsening heart failure events (54 [2·8%] vs 86 [4·7%]; HR 0·59 [0·41-0·82]; p=0·0019). No significant effect on cardiovascular death alone was seen (59 [3·1%] vs 67 [3·7%]; HR 0·82 [0·57-1·16]; p=0·25). A lower proportion of patients treated with semaglutide had serious adverse events than did those who were treated with placebo (572 [29·9%] vs 708 [38·7%]). INTERPRETATION: In patients with HFpEF, semaglutide reduced the risk of the combined endpoint of cardiovascular death or worsening heart failure events, and worsening heart failure events alone, whereas its effect on cardiovascular death alone was not significant. These data support the use of semaglutide as an efficacious therapy to reduce the risk of clinical heart failure events in patients with HFpEF, for whom few treatment options are currently available. FUNDING: Novo Nordisk.

Semaglutide and cardiovascular outcomes in patients with obesity and prevalent heart failure: a prespecified analysis of the SELECT trial.

BACKGROUND: Semaglutide, a GLP-1 receptor agonist, reduces the risk of major adverse cardiovascular events (MACE) in people with overweight or obesity, but the effects of this drug on outcomes in patients with atherosclerotic cardiovascular disease and heart failure are unknown. We report a prespecified analysis of the effect of once-weekly subcutaneous semaglutide 2·4 mg on ischaemic and heart failure cardiovascular outcomes. We aimed to investigate if semaglutide was beneficial in patients with atherosclerotic cardiovascular disease with a history of heart failure compared with placebo; if there was a difference in outcome in patients designated as having heart failure with preserved ejection fraction compared with heart failure with reduced ejection fraction; and if the efficacy and safety of semaglutide in patients with heart failure was related to baseline characteristics or subtype of heart failure. METHODS: The SELECT trial was a randomised, double-blind, multicentre, placebo-controlled, event-driven phase 3 trial in 41 countries. Adults aged 45 years and older, with a BMI of 27 kg/m2 or greater and established cardiovascular disease were eligible for the study. Patients were randomly assigned (1:1) with a block size of four using an interactive web response system in a double-blind manner to escalating doses of once-weekly subcutaneous semaglutide over 16 weeks to a target dose of 2·4 mg, or placebo. In a prespecified analysis, we examined the effect of semaglutide compared with placebo in patients with and without a history of heart failure at enrolment, subclassified as heart failure with preserved ejection fraction, heart failure with reduced ejection fraction, or unclassified heart failure. Endpoints comprised MACE (a composite of non-fatal myocardial infarction, non-fatal stroke, and cardiovascular death); a composite heart failure outcome (cardiovascular death or hospitalisation or urgent hospital visit for heart failure); cardiovascular death; and all-cause death. The study is registered with ClinicalTrials.gov, NCT03574597. FINDINGS: Between Oct 31, 2018, and March 31, 2021, 17 604 patients with a mean age of 61·6 years (SD 8·9) and a mean BMI of 33·4 kg/m2 (5·0) were randomly assigned to receive semaglutide (8803 [50·0%] patients) or placebo (8801 [50·0%] patients). 4286 (24·3%) of 17 604 patients had a history of investigator-defined heart failure at enrolment: 2273 (53·0%) of 4286 patients had heart failure with preserved ejection fraction, 1347 (31·4%) had heart failure with reduced ejection fraction, and 666 (15·5%) had unclassified heart failure. Baseline characteristics were similar between patients with and without heart failure. Patients with heart failure had a higher incidence of clinical events. Semaglutide improved all outcome measures in patients with heart failure at random assignment compared with those without heart failure (hazard ratio [HR] 0·72, 95% CI 0·60-0·87 for MACE; 0·79, 0·64-0·98 for the heart failure composite endpoint; 0·76, 0·59-0·97 for cardiovascular death; and 0·81, 0·66-1·00 for all-cause death; all pinteraction>0·19). Treatment with semaglutide resulted in improved outcomes in both the heart failure with reduced ejection fraction (HR 0·65, 95% CI 0·49-0·87 for MACE; 0·79, 0·58-1·08 for the composite heart failure endpoint) and heart failure with preserved ejection fraction groups (0·69, 0·51-0·91 for MACE; 0·75, 0·52-1·07 for the composite heart failure endpoint), although patients with heart failure with reduced ejection fraction had higher absolute event rates than those with heart failure with preserved ejection fraction. For MACE and the heart failure composite, there were no significant differences in benefits across baseline age, sex, BMI, New York Heart Association status, and diuretic use. Serious adverse events were less frequent with semaglutide versus placebo, regardless of heart failure subtype. INTERPRETATION: In patients with atherosclerotic cardiovascular diease and overweight or obesity, treatment with semaglutide 2·4 mg reduced MACE and composite heart failure endpoints compared with placebo in those with and without clinical heart failure, regardless of heart failure subtype. Our findings could facilitate prescribing and result in improved clinical outcomes for this patient group. FUNDING: Novo Nordisk.

Starting Insulin Algorithms for Noncritical Illness: A Survey of 32 Academic Hospitals in the United States.

Glycemic control immediately upon hospitalization is difficult. Endocrine Society guidelines suggest starting scheduled insulin therapy at 0.2-0.5 units/kg/day, but there has been no rigorous study to support this recommendation. To understand the variability of current practice, we surveyed starting insulin algorithms for noncritically ill patients among the top-ranking academic hospitals in the United States. Among the 20 hospitals with reported algorithms, 12 specified which patients should start with basal/nutritional insulin, whereas 5 specified who should start with only correction insulin. Weight-based and/or home-dose-based calculations were used to estimate the initial insulin requirements with various modifiers. In addition, various factors were considered when choosing among the correction dose algorithms. In summary, among the U.S. academic hospitals, there is variability in methods for determining insulin dosing on admission for noncritically ill patients. This inconsistency suggests that future studies to estimate initial insulin requirements are required.

Effect of Semaglutide on Regression and Progression of Glycemia in People With Overweight or Obesity but Without Diabetes in the SELECT Trial.

OBJECTIVE: To determine whether semaglutide slows progression of glycemia in people with cardiovascular disease and overweight or obesity but without diabetes. RESEARCH DESIGN AND METHODS: In a multicenter, double-blind trial, participants aged ≥45 years, with BMI ≥27 kg/m2, and with preexisting cardiovascular disease but without diabetes (HbA1c <6.5%) were randomized to receive subcutaneous semaglutide (2.4 mg weekly) or placebo. Major glycemic outcomes were HbA1c and proportions achieving biochemical normoglycemia (HbA1c <5.7%) and progressing to biochemical diabetes (HbA1c ≥6.5%). RESULTS: Of 17,604 participants, 8,803 were assigned to semaglutide and 8,801 to placebo. Mean ± SD intervention exposure was 152 ± 56 weeks and follow-up 176 ± 40 weeks. In both treatment arms mean nadir HbA1c for participants was at 20 weeks. Thereafter, HbA1c increased similarly in both arms, with a mean difference of -0.32 percentage points (95% CI -0.33 to -0.30; -3.49 mmol/mol [-3.66 to -3.32]) and with the difference favoring semaglutide throughout the study (P < 0.0001). Body weight plateaued at 65 weeks and was 8.9% lower with semaglutide. At week 156, a greater proportion treated with semaglutide were normoglycemic (69.5% vs. 35.8%; P < 0.0001) and a smaller proportion had biochemical diabetes by week 156 (1.5% vs. 6.9%; P < 0.0001). The number needed to treat was 18.5 to prevent a case of diabetes. Both regression and progression were dependent on glycemia at baseline, with the magnitude of weight reduction important in mediating 24.5% of progression and 27.1% of regression. CONCLUSIONS: In people with preexisting cardiovascular disease and overweight or obesity but without diabetes, long-term semaglutide increases regression to biochemical normoglycemia and reduces progression to biochemical diabetes but does not slow glycemic progression over time.

Semaglutide and Cardiovascular Outcomes by Baseline HbA1c and Change in HbA1c in People With Overweight or Obesity but Without Diabetes in SELECT.

OBJECTIVE: To evaluate the cardiovascular effects of semaglutide by baseline glycated hemoglobin (HbA1c) and change in HbA1c in a prespecified analysis of Semaglutide Effects on Cardiovascular Outcomes in People With Overweight or Obesity (SELECT). RESEARCH DESIGN AND METHODS: In SELECT, people with overweight or obesity and atherosclerotic cardiovascular disease without diabetes were randomized to weekly semaglutide 2.4 mg or placebo. The primary end point of first major adverse cardiovascular event (MACE) (cardiovascular mortality, nonfatal myocardial infarction, or stroke) was reduced by 20% with semaglutide versus placebo. Analysis of outcomes included first MACE, its individual components, expanded MACE (cardiovascular mortality, nonfatal myocardial infarction, or stroke; coronary revascularization; or hospitalization for unstable angina), a heart failure composite (heart failure hospitalization or urgent medical visit or cardiovascular mortality), coronary revascularization, and all-cause mortality by baseline HbA1c subgroup and categories of HbA1c change (<-0.3, -0.3 to 0.3, and >0.3 percentage points) from baseline to 20 weeks using the intention-to-treat principle with Cox proportional hazards. RESULTS: Among 17,604 participants (mean age 61.6 years, 72.3% male), baseline HbA1c was <5.7% for 33.5%, 5.7% to <6.0% for 34.6%, and 6.0% to <6.5% for 31.9%. Cardiovascular risk reduction with semaglutide versus placebo was not shown to be different across baseline HbA1c groups and was consistent with that of the overall study for all end points, except all-cause mortality. Cardiovascular outcomes were also consistent across subgroups of HbA1c change. CONCLUSIONS: In people with overweight or obesity and established atherosclerotic cardiovascular disease but not diabetes, semaglutide reduced cardiovascular events irrespective of baseline HbA1c or change in HbA1c. Thus, semaglutide is expected to confer cardiovascular benefits in people with established atherosclerotic cardiovascular disease who are normoglycemic at baseline and/or in those without HbA1c improvements.

The association of insulin responses and insulin sensitivity with cognition in adults with pre-diabetes: The Diabetes Prevention Program Outcomes Study.

OBJECTIVE: Dysglycemia is a significant risk factor for cognitive impairment. However, which pathophysiologic determinant(s) of dysglycemia, impaired insulin sensitivity (ISens) or the islet ß-cell's response (IResp), contribute to poorer cognitive function, independent of dysglycemia is not established. Among 1052 adults with pre-diabetes from the Diabetes Prevention Program Outcomes Study (DPPOS), we investigated the relationship between IResp, ISens and cognitive function. RESEARCH DESIGN AND METHODS: IResp was estimated by the insulinogenic index (IGI; pmol/mmol) and ISens as 1/fasting insulin from repeated annual oral glucose tolerance tests. The mean IResp and mean ISens were calculated over approximately 12 years of follow-up. Verbal learning (Spanish-English Verbal Learning Test [SEVLT]) and executive function (Digital Symbol Substitution Test [DSST]) were assessed at the end of the follow-up period. Linear regression models were run for each cognitive outcome and were adjusted for dysglycemia and other factors. RESULTS: Higher IResp was associated with poorer performance on the DSST (-0.69 points per 100 unit increase in IGI, 95 % CI: -1.37, -0.01). ISens was not associated with DSST, nor were IResp or ISens associated with performance on the SEVLT. CONCLUSIONS: These results suggest that a greater ß-cell response in people at high risk for type 2 diabetes is associated with poorer executive function, independent of dysglycemia and ISens.

Within and post-trial effects of an intensive lifestyle intervention on kidney disease in adults with overweight or obesity and type 2 diabetes mellitus: a secondary analysis of the Look AHEAD clinical trial.

INTRODUCTION: The Look AHEAD randomized clinical trial reported that an 8-year intensive lifestyle intervention (ILI) compared with diabetes support and education (DSE) in adults aged 45-76 years with type 2 diabetes and overweight/obesity delayed kidney disease progression. Here, we report long-term post-intervention follow-up for the trial's secondary outcome of kidney disease. RESEARCH DESIGN AND METHODS: We examined effects of ILI (n=2570) versus DSE (n=2575) on decline in estimated glomerular filtration rate (eGFR) to <45 mL/min/1.73 m2 or need for kidney replacement therapy (KRT: dialysis or kidney transplant) during intervention and post-intervention follow-up (median 15.6 years overall). RESULTS: Incidence of eGFR <45 mL/min/1.73 m2 was lower in ILI during the intervention (HR=0.80, 95% CI=0.66 to 0.98) but not post-intervention (HR=1.03, 0.86 to 1.23) or overall (HR=0.92, 0.80 to 1.04). There were no significant treatment group differences in KRT. In prespecified subgroup analyses, age×treatment interactions were significant over total follow-up: p=0.001 for eGFR <45 mL/min/1.73 m2 and p=0.01 for KRT. The 2205 participants aged >60 years at baseline had benefit in both kidney outcomes during intervention and overall (HR=0.75, 0.62 to 0.90 for eGFR <45 mL/min/1.73 m2; HR=0.62, 0.43 to 0.91 for KRT). The absolute treatment effects were greater post-intervention: ILI reduced the rate of eGFR <45 mL/min/1.73 m2 by 0.46 and 0.76 cases/100 person-years during and post-intervention, respectively; and reduced KRT by 0.15 and 0.21 cases/100 person-years. The younger participants experienced no such post-intervention benefits. CONCLUSIONS: ILI reduced kidney disease progression during and following the active intervention in persons aged ≥60 years. ILI should be considered for reducing kidney disease incidence in older persons with type 2 diabetes.

Long-term weight loss effects of semaglutide in obesity without diabetes in the SELECT trial.

In the SELECT cardiovascular outcomes trial, semaglutide showed a 20% reduction in major adverse cardiovascular events in 17,604 adults with preexisting cardiovascular disease, overweight or obesity, without diabetes. Here in this prespecified analysis, we examined effects of semaglutide on weight and anthropometric outcomes, safety and tolerability by baseline body mass index (BMI). In patients treated with semaglutide, weight loss continued over 65 weeks and was sustained for up to 4 years. At 208 weeks, semaglutide was associated with mean reduction in weight (-10.2%), waist circumference (-7.7 cm) and waist-to-height ratio (-6.9%) versus placebo (-1.5%, -1.3 cm and -1.0%, respectively; P < 0.0001 for all comparisons versus placebo). Clinically meaningful weight loss occurred in both sexes and all races, body sizes and regions. Semaglutide was associated with fewer serious adverse events. For each BMI category (<30, 30 to <35, 35 to <40 and ≥40 kg m-2) there were lower rates (events per 100 years of observation) of serious adverse events with semaglutide (43.23, 43.54, 51.07 and 47.06 for semaglutide and 50.48, 49.66, 52.73 and 60.85 for placebo). Semaglutide was associated with increased rates of trial product discontinuation. Discontinuations increased as BMI class decreased. In SELECT, at 208 weeks, semaglutide produced clinically significant weight loss and improvements in anthropometric measurements versus placebo. Weight loss was sustained over 4 years. ClinicalTrials.gov identifier: NCT03574597 .

Long-term kidney outcomes of semaglutide in obesity and cardiovascular disease in the SELECT trial.

The SELECT trial previously reported a 20% reduction in major adverse cardiovascular events with semaglutide (n = 8,803) versus placebo (n = 8,801) in patients with overweight/obesity and established cardiovascular disease, without diabetes. In the present study, we examined the effect of once-weekly semaglutide 2.4 mg on kidney outcomes in the SELECT trial. The incidence of the pre-specified main composite kidney endpoint (death from kidney disease, initiation of chronic kidney replacement therapy, onset of persistent estimated glomerular filtration rate (eGFR) < 15 ml min-1 1.73 m-2, persistent ≥50% reduction in eGFR or onset of persistent macroalbuminuria) was lower with semaglutide (1.8%) versus placebo (2.2%): hazard ratio (HR) = 0.78; 95% confidence interval (CI) 0.63, 0.96; P = 0.02. The treatment benefit at 104 weeks for eGFR was 0.75 ml min-1 1.73 m-2 (95% CI 0.43, 1.06; P < 0.001) overall and 2.19 ml min-1 1.73 m-2 (95% CI 1.00, 3.38; P < 0.001) in patients with baseline eGFR <60 ml min-1 1.73 m-2. These results suggest a benefit of semaglutide on kidney outcomes in individuals with overweight/obesity, without diabetes.ClinicalTrials.gov identifier: NCT03574597 .

Increased Genetic Risk for ß-Cell Failure Is Associated With ß-Cell Function Decline in People With Prediabetes.

Partitioned polygenic scores (pPS) have been developed to capture pathophysiologic processes underlying type 2 diabetes (T2D). We investigated the association of T2D pPS with diabetes-related traits and T2D incidence in the Diabetes Prevention Program. We generated five T2D pPS (ß-cell, proinsulin, liver/lipid, obesity, lipodystrophy) in 2,647 participants randomized to intensive lifestyle, metformin, or placebo arms. Associations were tested with general linear models and Cox regression with adjustment for age, sex, and principal components. Sensitivity analyses included adjustment for BMI. Higher ß-cell pPS was associated with lower insulinogenic index and corrected insulin response at 1-year follow-up with adjustment for baseline measures (effect per pPS SD -0.04, P = 9.6 × 10-7, and -8.45 µU/mg, P = 5.6 × 10-6, respectively) and with increased diabetes incidence with adjustment for BMI at nominal significance (hazard ratio 1.10 per SD, P = 0.035). The liver/lipid pPS was associated with reduced 1-year baseline-adjusted triglyceride levels (effect per SD -4.37, P = 0.001). There was no significant interaction between T2D pPS and randomized groups. The remaining pPS were associated with baseline measures only. We conclude that despite interventions for diabetes prevention, participants with a high genetic burden of the ß-cell cluster pPS had worsening in measures of ß-cell function.

Prevalence of Distal Symmetrical Polyneuropathy by Diabetes Prevention Program Treatment Group, Diabetes Status, Duration of Diabetes, and Cumulative Glycemic Exposure.

OBJECTIVE: To assess associations between distal symmetric polyneuropathy (DSPN) and Diabetes Prevention Program (DPP) treatment groups, diabetes status or duration, and cumulative glycemic exposure approximately 21 years after DPP randomization. RESEARCH DESIGN AND METHODS: In the DPP, 3,234 adults ≥25 years old at high risk for diabetes were randomized to an intensive lifestyle (ILS), metformin, or placebo intervention to prevent diabetes. After the DPP ended, 2,779 joined the Diabetes Prevention Program Outcomes Study (DPPOS). Open-label metformin was continued, placebo was discontinued, ILS was provided in the form of semiannual group-based classes, and all participants were offered quarterly lifestyle classes. Symptoms and signs of DSPN were assessed in 1,792 participants at DPPOS year 17. Multivariable logistic regression models were used to evaluate DSPN associations with treatment group, diabetes status/duration, and cumulative glycemic exposure. RESULTS: At 21 years after DPP randomization, 66% of subjects had diabetes. DSPN prevalence did not differ by initial DPP treatment assignment (ILS 21.5%, metformin 21.5%, and placebo 21.9%). There was a significant interaction between treatment assignment to ILS and age (P < 0.05) on DSPN. At DPPOS year 17, the odds ratio for DSPN in comparison with ILS with placebo was 17.4% (95% CI 3.0, 29.3) lower with increasing 5-year age intervals. DSPN prevalence was slightly lower for those at risk for diabetes (19.6%) versus those with diabetes (22.7%) and was associated with longer diabetes duration and time-weighted HbA1c (P values <0.001). CONCLUSIONS: The likelihood of DSPN was similar across DPP treatment groups but higher for those with diabetes, longer diabetes duration, and higher cumulative glycemic exposure. ILS may have long-term benefits on DSPN for older adults.

GAD65Abs Are Not Associated With Beta-Cell Dysfunction in Patients With T2D in the GRADE Study.

Context: Autoantibodies directed against the 65-kilodalton isoform of glutamic acid decarboxylase (GAD65Abs) are markers of autoimmune type 1 diabetes (T1D) but are also present in patients with Latent Autoimmune Diabetes of Adults and autoimmune neuromuscular diseases, and also in healthy individuals. Phenotypic differences between these conditions are reflected in epitope-specific GAD65Abs and anti-idiotypic antibodies (anti-Id) against GAD65Abs. We previously reported that 7.8% of T2D patients in the GRADE study have GAD65Abs but found that GAD65Ab positivity was not correlated with beta-cell function, glycated hemoglobin (HbA1c), or fasting glucose levels. Context: In this study, we aimed to better characterize islet autoantibodies in this T2D cohort. This is an ancillary study to NCT01794143. Methods: We stringently defined GAD65Ab positivity with a competition assay, analyzed GAD65Ab-specific epitopes, and measured GAD65Ab-specific anti-Id in serum. Results: Competition assays confirmed that 5.9% of the patients were GAD65Ab positive, but beta-cell function was not associated with GAD65Ab positivity, GAD65Ab epitope specificity or GAD65Ab-specific anti-Id. GAD65-related autoantibody responses in GRADE T2D patients resemble profiles in healthy individuals (low GAD65Ab titers, presence of a single autoantibody, lack of a distinct epitope pattern, and presence of anti-Id to diabetes-associated GAD65Ab). In this T2D cohort, GAD65Ab positivity is likely unrelated to the pathogenesis of beta-cell dysfunction. Conclusion: Evidence for islet autoimmunity in the pathophysiology of T2D beta-cell dysfunction is growing, but T1D-associated autoantibodies may not accurately reflect the nature of their autoimmune process.