Daily Oral GLP-1 Receptor Agonist Orforglipron for Adults with Obesity.

BACKGROUND: Obesity is a major risk factor for many leading causes of illness and death worldwide. Data are needed regarding the efficacy and safety of the nonpeptide glucagon-like peptide-1 (GLP-1) receptor agonist orforglipron as a once-daily oral therapy for weight reduction in adults with obesity. METHODS: In this phase 2, randomized, double-blind trial, we enrolled adults with obesity, or with overweight plus at least one weight-related coexisting condition, and without diabetes. Participants were randomly assigned to receive orforglipron at one of four doses (12, 24, 36, or 45 mg) or placebo once daily for 36 weeks. The percentage change from baseline in body weight was assessed at week 26 (primary end point) and at week 36 (secondary end point). RESULTS: A total of 272 participants underwent randomization. At baseline, the mean body weight was 108.7 kg, and the mean body-mass index (the weight in kilograms divided by the square of the height in meters) was 37.9. At week 26, the mean change from baseline in body weight ranged from -8.6% to -12.6% across the orforglipron dose cohorts and was -2.0% in the placebo group. At week 36, the mean change ranged from -9.4% to -14.7% with orforglipron and was -2.3% with placebo. A weight reduction of at least 10% by week 36 occurred in 46 to 75% of the participants who received orforglipron, as compared with 9% who received placebo. The use of orforglipron led to improvement in all prespecified weight-related and cardiometabolic measures. The most common adverse events reported with orforglipron were gastrointestinal events, which were mild to moderate, occurred primarily during dose escalation, and led to discontinuation of orforglipron in 10 to 17% of participants across dose cohorts. The safety profile of orforglipron was consistent with that of the GLP-1 receptor agonist class. CONCLUSIONS: Daily oral orforglipron, a nonpeptide GLP-1 receptor agonist, was associated with weight reduction. Adverse events reported with orforglipron were similar to those with injectable GLP-1 receptor agonists. (Funded by Eli Lilly; GZGI ClinicalTrials.gov number, NCT05051579.).

Efficacy and safety of oral orforglipron in patients with type 2 diabetes: a multicentre, randomised, dose-response, phase 2 study.

BACKGROUND: Orforglipron, an oral, non-peptide glucagon-like peptide-1 (GLP-1) receptor agonist, is in development for type 2 diabetes and obesity. We assessed the efficacy and safety of orforglipron versus placebo or dulaglutide in participants with type 2 diabetes. METHODS: In this 26-week, phase 2, double-blind, randomised, multicentre study, participants were recruited from 45 centres (private clinics, hospitals, and research centers) in the USA, Hungary, Poland, and Slovakia. Adult participants aged 18 years or older with type 2 diabetes treated with diet and exercise, with or without metformin, and with a glycated haemoglobin (HbA1c) of 7·0-10·5%, and stable BMI of 23 kg/m2 or more, were randomly assigned (5:5:5:5:5:3:3:3:3) via an interactive web-response system to placebo, dulaglutide 1·5 mg once per week, or orforglipron 3 mg, 12 mg, 24 mg, 36 mg (group 1), 36 mg (group 2), 45 mg (group 1), or 45 mg (group 2) once per day with no food or water restrictions. Two different dose escalation regimens were evaluated for each of the 36 mg and 45 mg cohorts. Participants were masked to the study drug, dulaglutide, and placebo. The primary efficacy outcome The primary efficacy outcome was mean change in HbA1c from baseline with orforglipron versus placebo at week 26. Efficacy was analysed in all randomly assigned participants who received at least one dose of study drug and excluded data after the permanent discontinuation of study drug or initiation of rescue medication. Safety was analysed in all participants who received at least one dose of study treatment. This trial is registered at ClinicalTrials.gov (NCT05048719) and is completed. FINDINGS: Between Sept 15, 2021, and Sept 30, 2022, 569 participants were screened and 383 were enrolled and randomly assigned to a group. 352 (92%) completed the study and 303 (79%) completed 26 weeks of treatment. At baseline, the mean age was 58·9 years, HbA1c was 8·1%, BMI was 35·2 kg/m2, 226 (59%) were men, and 157 (41%) were women. At week 26, mean change in HbA1c with orforglipron was up to -2·10% (-1·67% placebo adjusted), versus -0·43% with placebo and -1·10% with dulaglutide. HbA1c reduction was statistically superior with orforglipron versus placebo (estimated treatment difference -0·8% to -1·7%). Change in mean bodyweight at week 26 was up to -10·1 kg (95% CI -11·5 to -8·7; 7·9 kg placebo adjusted [-9·9 to -5·9]) with orforglipron versus -2·2 kg (-3·6 to -0·7) for placebo and -3·9 kg (-5·3 to -2·4) for dulaglutide. The incidence of treatment-emergent adverse events ranged from 61·8% to 88·9% in orforglipron-treated participants, compared with 61·8% with placebo and 56·0% with dulaglutide. The majority were gastrointestinal events (44·1% to 70·4% with orforglipron, 18·2% with placebo, and 34·0% with dulaglutide) of mild to moderate severity. Three participants receiving orforglipron and one participant receiving dulaglutide had clinically significant (<54 mg/dL [<3 mmol/L]) hypoglycaemia and no participants had severe hypoglycaemia. One death occurred in the placebo group and was not related to study treatment. INTERPRETATION: In this phase 2 trial the novel, oral, non-peptide GLP-1 receptor agonist orforglipron at doses of 12 mg or greater showed significant reductions in HbA1c and bodyweight compared with placebo or dulaglutide. The adverse event profile was similar to other GLP-1 receptor agonists in similar stage of development. Orforglipron might provide an alternative to injectable GLP-1 receptor agonists and oral semaglutide, with the prospect of less burdensome administration to achieve treatment goals in people with type 2 diabetes. FUNDING: Eli Lilly and Company.

Quantitative trait loci, G×E and G×G for glycemic traits: response to metformin and placebo in the Diabetes Prevention Program (DPP).

The complex genetic architecture of type-2-diabetes (T2D) includes gene-by-environment (G×E) and gene-by-gene (G×G) interactions. To identify G×E and G×G, we screened markers for patterns indicative of interactions (relationship loci [rQTL] and variance heterogeneity loci [vQTL]). rQTL exist when the correlation between multiple traits varies by genotype and vQTL occur when the variance of a trait differs by genotype (potentially flagging G×G and G×E). In the metformin and placebo arms of the DPP (n = 1762) we screened 280,965 exomic and intergenic SNPs, for rQTL and vQTL patterns in association with year one changes from baseline in glycemia and related traits (insulinogenic index [IGI], insulin sensitivity index [ISI], fasting glucose and fasting insulin). Significant (p < 1.8 × 10-7) rQTL and vQTL generated a priori hypotheses of individual G×E tests for a SNP × metformin treatment interaction and secondarily for G×G screens. Several rQTL and vQTL identified led to 6 nominally significant (p < 0.05) metformin treatment × SNP interactions (4 for IGI, one insulin, and one glucose) and 12G×G interactions (all IGI) that exceeded experiment-wide significance (p < 4.1 × 10-9). Some loci are directly associated with incident diabetes, and others are rQTL and modify a trait's relationship with diabetes (2 diabetes/glucose, 2 diabetes/insulin, 1 diabetes/IGI). rs3197999, an ISI/insulin rQTL, is a possible gene damaging missense mutation in MST1, is associated with ulcerative colitis, sclerosing cholangitis, Crohn's disease, BMI and coronary artery disease. This study demonstrates evidence for context-dependent effects (G×G & G×E) and the complexity of these T2D-related traits.

The linearized disposition index augments understanding of treatment effects in diabetes.

The disposition index, calculated by multiplying measures of insulin secretion and insulin sensitivity, is widely applied as a sensitivity-adjusted measure of insulin secretion. We have recently shown that linearizing the underlying relationship uniquely permits identification of terms relating to maximal insulin secretion capacity and the secretion-coupling relationship, with both terms separately contributing to differences in the secretion-sensitivity relationship across gradations of glycemia. Here, we demonstrate the application of this linearized equation to the evaluation of treatment-induced changes in the insulin secretion-sensitivity relationship. We applied a combination of repeated-measures multivariate linear regression (evaluating treatment-induced changes in the joint relationship of insulin sensitivity and secretion) plus mixed-model repeated measures (evaluating treatment effects on maximal secretion capacity and on the secretion-sensitivity coupling slope) and compared against a usual application of the disposition index calculated from the same measurements. This novel approach allows a more informative description of treatment-induced changes compared with the usual disposition index, including isolating the source of change within the mutually adjusted relationship and identifying treatment-induced changes in the secretion-sensitivity coupling slope and in maximal insulin secretion. Application of this linearized approach provides an expanded understanding of treatment-induced changes in the insulin sensitivity-secretion relationship.NEW & NOTEWORTHY The linearized insulin secretion-sensitivity relationship allows separate evaluation of the secretion-sensitivity slope and of maximal insulin secretion. Here, we demonstrate the application of this methodology to the evaluation of clinical trial data, showing that it provides an expanded understanding of treatment-induced changes compared with the disposition index.

Precision and accuracy of hyperglycemic clamps in a multicenter study.

Application of glucose clamp methodologies in multicenter studies brings challenges for standardization. The Restoring Insulin Secretion (RISE) Consortium implemented a hyperglycemic clamp protocol across seven centers using a combination of technical and management approaches to achieve standardization. Two-stage hyperglycemic clamps with glucose targets of 200 mg/dL and >450 mg/dL were performed utilizing a centralized spreadsheet-based algorithm that guided dextrose infusion rates using bedside plasma glucose measurements. Clamp operators received initial and repeated training with ongoing feedback based on surveillance of clamp performance. The precision and accuracy of the achieved stage-specific glucose targets were evaluated, including differences by study center. We also evaluated robustness of the method to baseline physiologic differences and on-study treatment effects. The RISE approach produced high overall precision (3%-9% variance in achieved plasma glucose from target at various times across the procedure) and accuracy (SD < 10% overall). Statistically significant but numerically small differences in achieved target glucose concentrations were observed across study centers, within the magnitude of the observed technical variability. Variation of the achieved target glucose over time in placebo-treated individuals was low (<3% variation), and the method was robust to differences in baseline physiology (youth vs. adult, IGT vs. diabetes status) and differences in physiology induced by study treatments. The RISE approach to standardization of the hyperglycemic clamp methodology across multiple study centers produced technically excellent standardization of achieved glucose concentrations. This approach provides a reliable method for implementing glucose clamp methodology across multiple study centers.NEW & NOTEWORTHY The Restoring Insulin Secretion (RISE) study centers undertook hyperglycemic clamps using a simplified methodology and a decision guidance algorithm implemented in an easy-to-use spreadsheet. This approach, combined with active management including ongoing central data surveillance and routine feedback to study centers, produced technically excellent standardization of achieved glucose concentrations on repeat studies within and across study centers.

Influence of patient immigrant status on physician trainee diabetes treatment decisions: a virtual patient experimental study.

To determine the effect of patient immigrant status on physician trainees' diabetes treatment decisions. Participants were 140 physician trainees ('providers'). Providers viewed videos and vignettes of virtual patients differing in immigrant status (born in Mexico or U.S.; other characteristics held constant). Analyses were completed at the group and individual levels. Providers were less likely to refer foreign-born (vs. U.S.-born) patients to endocrinology. Individual-level results showed an almost even split between treatment ratings for foreign-born vs. U.S.-born patients for three decisions (take no action, add oral hypoglycemic agent, add/switch to insulin), explaining why group-level differences for these ratings did not emerge (i.e., they were cancelled out). Physician trainees are less likely to refer foreign-born patients to endocrinology. Half of individual-level decisions were influenced by patient immigrant status, but group-level analyses mask these differences. Systematic treatment differences based on non-relevant factors could lead to adverse outcomes for immigrants.

Cell-Free DNA Fragments as Biomarkers of Islet ß-Cell Death in Obesity and Type 2 Diabetes.

Type 2 diabetes (T2D) typically occurs in the setting of obesity and insulin resistance, where hyperglycemia is associated with decreased pancreatic ß-cell mass and function. Loss of ß-cell mass has variably been attributed to ß-cell dedifferentiation and/or death. In recent years, it has been proposed that circulating epigenetically modified DNA fragments arising from ß cells might be able to report on the potential occurrence of ß-cell death in diabetes. Here, we review published literature of DNA-based ß-cell death biomarkers that have been evaluated in human cohorts of islet transplantation, type 1 diabetes, and obesity and type 2 diabetes. In addition, we provide new data on the applicability of one of these biomarkers (cell free unmethylated INS DNA) in adult cohorts across a spectrum from obesity to T2D, in which no significant differences were observed, and compare these findings to those previously published in youth cohorts where differences were observed. Our analysis of the literature and our own data suggest that ß-cell death may occur in subsets of individuals with obesity and T2D, however a more sensitive method or refined study designs are needed to provide better alignment of sampling with disease progression events.

Salicylate administration suppresses the inflammatory response to nutrients and improves ovarian function in polycystic ovary syndrome.

Oxidative stress (OS) and inflammation are often present in polycystic ovary syndrome (PCOS). We examined the effects of salsalate treatment on nutrient-induced OS and inflammation, ovarian androgen secretion, ovulation, and insulin sensitivity in PCOS. Eight lean insulin-sensitive women with PCOS and eight age- and body composition-matched ovulatory controls for baseline comparison participated in the study. The women with PCOS underwent a 12-wk treatment of salsalate, a nonsteroidal anti-inflammatory drug, at a dose of 3 g daily. Markers of OS and inflammation were quantified in mononuclear cells (MNC) and plasma from blood drawn fasting and 2 h after saturated fat ingestion before and after treatment. Ovarian androgen secretion was assessed from blood drawn fasting and 24, 48, and 72 h after human chorionic gonadotropin (HCG) administration before and after treatment. Ovulation was documented based on biphasic basal body temperatures and luteal range progesterone elevations. A two-step pancreatic clamp was performed pre- and posttreatment to measure basal endogenous glucose production (EGP) and the steady-state glucose disposal rate (GDR) during the euglycemic phase and markers of OS and inflammation in MNC and plasma during the hyperglycemic phase. Salsalate administration suppressed lipid- and glucose-stimulated reactive oxygen species generation, activated nuclear factor-κB and circulating tumor necrosis factor-α, normalized basal androgen levels, and lowered HCG-stimulated androgen secretion without altering EGP or GDR. Four salsalate-treated subjects responded with two consecutive ovulations. We conclude that in PCOS, salsalate-induced suppression of OS and inflammation ameliorates ovarian androgen hypersecretion and may induce ovulation while maintaining insulin action.

Withdrawal of medications leads to worsening of OGTT parameters in youth with impaired glucose tolerance or recently-diagnosed type 2 diabetes.

BACKGROUND: The RISE Pediatric Medication Study compared strategies for preserving ß-cell function, including a 9-month follow-up after treatment withdrawal to test treatment effect durability. OBJECTIVE: Evaluate OGTT measures of glucose and ß-cell response through 12 months of intervention and 9 months of medication washout. PARTICIPANTS: Youth (n = 91) aged 10 to 19 years with BMI ≥85th percentile and impaired glucose tolerance (IGT) or recently diagnosed type 2 diabetes (T2D). METHODS: A multicenter randomized clinical trial comparing insulin glargine for 3 months followed by metformin for 9 months (G→Met) or metformin alone (Met) for 12 months. We report within-group changes from baseline to end of medication intervention (M12), baseline to 9 months post-medication withdrawal (M21), and end of medication (M12) to M21. OGTT C-peptide index [CPI] paired with 1/fasting insulin evaluated ß-cell response. RESULTS: At M12, both treatments were associated with stable fasting glucose (G→Met baseline 6.0 ± 0.1 vs M12 5.9 ± 0.2 mmol/L, P = .62; Met baseline 6.1 ± 0.2 vs M12 6.0 ± 0.2 mmol/L, P = .73) and 2-hour glucose (G→Met baseline 10.2 ± 0.4 vs M12 9.3 ± 0.5 mmol/L, P = .03; Met baseline 10.2 ± 0.4 vs M12 10.6 ± 0.6 mmol/L, P = .88). Following medication withdrawal, fasting glucose worsened (G→Met M21 8.6 ± 1.8, P = .004; Met M21 7.8 ± 0.7 mmol/L, P = .003), as did 2-hour glucose (G→Met M21 13.2 ± 1.4, P = .002; Met M21 13.1 ± 1.2 mmol/L, P = .006), associated with declines in ß-cell response. CONCLUSIONS: G→Met and Met were associated with stable glucose measures during 12 months of treatment in youth with IGT or recently diagnosed T2D. Glucose and ß-cell response worsened post-medication withdrawal, suggesting treatment must be long-term or alternative treatments pursued.

ß-cells in youth with impaired glucose tolerance or early type 2 diabetes secrete more insulin and are more responsive than in adults.

OBJECTIVE: Glycemic control deteriorates more rapidly in youth vs adults. We compared model-derived measures of ß-cell function between youth and adults with either impaired glucose tolerance (IGT) or type 2 diabetes to determine if a ß-cell defect differentiates these age groups. METHODS: This is a cross-sectional analysis of baseline data from the Restoring Insulin Secretion (RISE) Study. Youth (54 Y-IGT, 33 Y-D) and adults (250 A-IGT, 104 A-D) underwent 3-hour oral glucose tolerance tests for modeling of insulin secretion rates (ISRs), glucose sensitivity, and rate sensitivity. Insulin sensitivity was quantified as the glucose infusion rate/insulin (M/I) from a hyperglycemic clamp. RESULTS: Youth had lower insulin sensitivity despite similar body mass index. Analyses were adjusted for insulin sensitivity. Youth had higher basal ISRs (Y-IGT 200 ± 161 vs A-IGT 152 ± 74, P < .001; Y-D 245 ± 2.5 vs A-D 168 ± 115 pmol/min/m2 , P = .007) and total ISRs (Y-IGT 124 ± 86 vs A-IGT 98 ± 39, P < .001; Y-D 116 ± 110 vs A-D 97 ± 62 nmol/m2 , P = .002). Within IGT, glucose sensitivity (Y-IGT 140 ± 153 vs A-IGT 112 ± 70 pmol/min/m2 /mM, P = .004) and rate sensitivity (median[interquartile range]:Y-IGT 2271[1611, 3222] vs A-IGT 1164[685, 1565] pmol/m2 /mM, P < .001) were higher in youth, but not different by age group within diabetes. CONCLUSIONS: Model-derived measures of ß-cell function provide additional insight into the pathophysiology of type 2 diabetes in youth with higher ISRs and ß-cell secretion more responsive to glucose in youth relative to adults even after adjusting for differences in insulin sensitivity. It is unknown whether these findings in youth reflect ß-cells that are healthier or whether this is a defect that contributes to more rapid loss of function.

Non-traditional biomarkers and incident diabetes in the Diabetes Prevention Program: comparative effects of lifestyle and metformin interventions.

AIMS/HYPOTHESIS: We compared the associations of circulating biomarkers of inflammation, endothelial and adipocyte dysfunction and coagulation with incident diabetes in the placebo, lifestyle and metformin intervention arms of the Diabetes Prevention Program, a randomised clinical trial, to determine whether reported associations in general populations are reproduced in individuals with impaired glucose tolerance, and whether these associations are independent of traditional diabetes risk factors. We further investigated whether biomarker-incident diabetes associations are influenced by interventions that alter pathophysiology, biomarker concentrations and rates of incident diabetes. METHODS: The Diabetes Prevention Program randomised 3234 individuals with impaired glucose tolerance into placebo, metformin (850 mg twice daily) and intensive lifestyle groups and showed that metformin and lifestyle reduced incident diabetes by 31% and 58%, respectively compared with placebo over an average follow-up period of 3.2 years. For this study, we measured adiponectin, leptin, tissue plasminogen activator (as a surrogate for plasminogen activator inhibitor 1), high-sensitivity C-reactive protein, IL-6, monocyte chemotactic protein 1, fibrinogen, E-selectin and intercellular adhesion molecule 1 at baseline and at 1 year by specific immunoassays. Traditional diabetes risk factors were defined as family history, HDL-cholesterol, triacylglycerol, BMI, fasting and 2 h glucose, HbA1c, systolic blood pressure, inverse of fasting insulin and insulinogenic index. Cox proportional hazard models were used to assess the effects of each biomarker on the development of diabetes assessed semi-annually and the effects of covariates on these. RESULTS: E-selectin, (HR 1.19 [95% CI 1.06, 1.34]), adiponectin (0.84 [0.71, 0.99]) and tissue plasminogen activator (1.13 [1.03, 1.24]) were associated with incident diabetes in the placebo group, independent of diabetes risk factors. Only the association between adiponectin and diabetes was maintained in the lifestyle (0.69 [0.52, 0.92]) and metformin groups (0.79 [0.66, 0.94]). E-selectin was not related to diabetes development in either lifestyle or metformin groups. A novel association appeared for change in IL-6 in the metformin group (1.09 [1.021, 1.173]) and for baseline leptin in the lifestyle groups (1.31 [1.06, 1.63]). CONCLUSIONS/INTERPRETATION: These findings clarify associations between an extensive group of biomarkers and incident diabetes in a multi-ethnic cohort with impaired glucose tolerance, the effects of diabetes risk factors on these, and demonstrate differential modification of associations by interventions. They strengthen evidence linking adiponectin to diabetes development, and argue against a central role for endothelial dysfunction. The findings have implications for the pathophysiology of diabetes development and its prevention.

Does diabetes prevention translate into reduced long-term vascular complications of diabetes?

The global epidemic of type 2 diabetes has prompted numerous studies and public health efforts to reduce its development. A variety of interventions, including lifestyle modifications and pharmacological agents directed at ameliorating the major risk factors for type 2 diabetes, are of proven efficacy in reducing the development of type 2 diabetes in people with impaired glucose tolerance. While prevention of the hyperglycaemia characteristic of diabetes is arguably an important, clinically relevant outcome, a more compelling outcome with greater clinical significance is the prevention or reduction of the relatively diabetes-specific microvascular and less-specific cardiovascular disease (CVD) complications associated with diabetes. These complications cause the majority of morbidity and excess mortality associated with diabetes. Any reduction in diabetes should, logically, also reduce the occurrence of its long-term complications; however, most diabetes prevention trials have not been of sufficient duration to allow such an evaluation. The limited long-term data, largely from the Da Qing Diabetes Prevention Study (DQDPS) and the Diabetes Prevention Program (DPP) and their respective follow-up studies (DQDPOS and DPPOS), suggest a reduction in microvascular complications and amelioration of CVD risk factors. Only the DQDPOS and Study to Prevent Non-Insulin-Dependent Diabetes Mellitus (STOP-NIDDM) studies have shown a reduction in CVD events and only DQDPOS has demonstrated a decrease in CVD and overall mortality. While these limited data are promising, whether diabetes prevention directly reduces complication-related morbidity and mortality remains unclear. Longer follow-up of prevention studies is needed to supplement the limited current clinical trial data, to help differentiate the effects of diabetes prevention itself from the means used to reduce diabetes development and to understand the balance among benefits, risks and costs of prevention.

Inhibition of sodium-glucose cotransporter-2 preserves cardiac function during regional myocardial ischemia independent of alterations in myocardial substrate utilization.

The goal of the present study was to evaluate the effects of SGLT2i on cardiac contractile function, substrate utilization, and efficiency before and during regional myocardial ischemia/reperfusion injury in normal, metabolically healthy swine. Lean swine received placebo or canagliflozin (300 mg PO) 24 h prior to and the morning of an invasive physiologic study protocol. Hemodynamic and cardiac function measurements were obtained at baseline, during a 30-min complete occlusion of the circumflex coronary artery, and during a 2-h reperfusion period. Blood pressure, heart rate, coronary flow, and myocardial oxygen consumption were unaffected by canagliflozin treatment. Ventricular volumes remained unchanged in controls throughout the protocol. At the onset of ischemia, canagliflozin produced acute large increases in left ventricular end-diastolic and systolic volumes which returned to baseline with reperfusion. Canagliflozin-mediated increases in end-diastolic volume were directly associated with increases in stroke volume and stroke work relative to controls during ischemia. Canagliflozin also increased cardiac work efficiency during ischemia relative to control swine. No differences in myocardial uptake of glucose, lactate, free fatty acids or ketones, were noted between treatment groups at any time. In separate experiments using a longer 60 min coronary occlusion followed by 2 h of reperfusion, canagliflozin increased end-diastolic volume and stroke volume and significantly diminished myocardial infarct size relative to control swine. These data demonstrate that SGLT2i with canagliflozin preserves cardiac contractile function and efficiency during regional myocardial ischemia and provides ischemia protection independent of alterations in myocardial substrate utilization.

Episodic ß-cell death and dedifferentiation during diet-induced obesity and dysglycemia in male mice.

Loss of functional islet ß-cell mass through cellular death or dedifferentiation is thought to lead to dysglycemia during the progression from obesity to type 2 diabetes. To assess these processes in a mouse model of obesity, we performed measures of circulating cell-free differentially methylated insulin II ( Ins2) DNA as a biomarker of ß-cell death and aldehyde dehydrogenase 1 family member A3 (ALDH1A3) and forkhead box 01 (Foxo1) immunostaining as markers of ß-cell dedifferentiation. Eight-week-old, C57BL/6J mice were fed a low-fat diet (LFD; 10% kcal from fat) or a high-fat diet (HFD; 60% kcal from fat) and were followed longitudinally for up to 13 wk to measure glycemic control and ß-cell mass, death, and dedifferentiation. Compared with LFD controls, ß-cell mass increased during the feeding period in HFD animals, and statistically greater ß-cell death (unmethylated Ins2) was detectable at 2 and 6 wk after diet initiation. Those times correspond to periods when significant step increases in fasting glucose and glucose intolerance, respectively, were detected. ALDH1A3 and Foxo1 immunostaining of the pancreas revealed evidence of ß-cell dedifferentiation by 13 wk when fed an HFD, but not in LFD controls. In conclusion, early episodic ß-cell death may be a feature of cellular turnover correlated with changes in glycemia during ß-cell mass accrual in obesity, whereas ß-cell dedifferentiation may be a feature seen later in established disease.-Tersey, S. A., Levasseur, E. M., Syed, F., Farb, T. B., Orr, K. S., Nelson, J. B., Shaw, J. L., Bokvist, K., Mather, K. J., Mirmira, R. G. Episodic ß-cell death and dedifferentiation during diet-induced obesity and dysglycemia in male mice.

Effect of Long-Term Metformin and Lifestyle in the Diabetes Prevention Program and Its Outcome Study on Coronary Artery Calcium.

BACKGROUND: Despite the reduced incidence of coronary heart disease with intensive risk factor management, people with diabetes mellitus and prediabetes remain at increased coronary heart disease risk. Diabetes prevention interventions may be needed to reduce coronary heart disease risk. This approach was examined in the DPP (Diabetes Prevention Program) and the DPPOS (Diabetes Prevention Program Outcome Study), a long-term intervention study in 3234 subjects with prediabetes (mean±SD age, 64±10 years) that showed reduced diabetes risk with lifestyle and metformin compared with placebo over 3.2 years. METHODS: The DPPOS offered periodic group lifestyle sessions to all participants and continued metformin in the originally randomized metformin group. Subclinical atherosclerosis was assessed in 2029 participants with coronary artery calcium (CAC) measurements after an average of 14 years of follow-up. The CAC scores were analyzed continuously as CAC severity and categorically as CAC presence (CAC score >0) and reported separately in men and women. RESULTS: There were no CAC differences between lifestyle and placebo intervention groups in either sex. CAC severity and presence were significantly lower among men in the metformin versus the placebo group (age-adjusted mean CAC severity, 39.5 versus 66.9 Agatston units, P=0.04; CAC presence, 75% versus 84%, P=0.02), but no metformin effect was seen in women. In multivariate analysis, the metformin effect in men was not influenced by demographic, anthropometric, or metabolic factors; by the development of diabetes mellitus; or by use/nonuse of statin therapy. CONCLUSIONS: Metformin may protect against coronary atherosclerosis in prediabetes and early diabetes mellitus among men. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00038727.

Depressive Symptoms, Antidepressant Medication Use, and Inflammatory Markers in the Diabetes Prevention Program.

OBJECTIVE: Antidepressant medication use (ADM) has been shown to predict diabetes. This article assessed the role of inflammatory markers in this relationship within the Diabetes Prevention Program (DPP). METHODS: DPP participants randomized to metformin (MET), life-style intervention (ILS), or placebo (PLB) were assessed for depression (Beck Depression Inventory [BDI]) annually, ADM use semiannually, serum inflammatory markers (C-reactive protein [CRP], interleukin 6 [IL-6]) at baseline and year 1, and diagnosis of type 2 diabetes mellitus (T2DM) semiannually (for 3.2 years). RESULTS: At baseline (N = 3187), M (SD) body mass index was 34 (6) kg/m and the median (interquartile range) BDI score was 3 (1-7). One hundred eighty-one (5.7%) reported ADM use and 328 (10%) had BDI scores of 11 or higher. CRP and IL-6 levels did not differ by treatment group. Baseline ADM, but not BDI score, was associated with higher levels of baseline CRP adjusted for demographic, anthropometric variables, and other medications (20% higher, p = .01). Year 1 CRP decreased for non-ADM users in the MET (-13.2%) and ILS (-34%) groups and ADM users in the ILS group (-29%). No associations were found with IL-6. CRP and continuous use of ADM predicted incident T2DM in the PLB group. In the ILS group, continuous and intermittent ADM, but not CRP, predicted T2DM. In the MET group, CRP predicted incident T2DM. CRP did not mediate the risk of T2DM with ADM use in any group. CONCLUSIONS: ADM was significantly associated with elevated CRP and incident T2DM. In the PLB group, ADM and CRP independently predicted onset of T2DM; however, CRP did not significantly mediate the effect of ADM.

Review of methods for measuring ß-cell function: Design considerations from the Restoring Insulin Secretion (RISE) Consortium.

The Restoring Insulin Secretion (RISE) study was initiated to evaluate interventions to slow or reverse the progression of ß-cell failure in type 2 diabetes (T2D). To design the RISE study, we undertook an evaluation of methods for measurement of ß-cell function and changes in ß-cell function in response to interventions. In the present paper, we review approaches for measurement of ß-cell function, focusing on methodologic and feasibility considerations. Methodologic considerations included: (1) the utility of each technique for evaluating key aspects of ß-cell function (first- and second-phase insulin secretion, maximum insulin secretion, glucose sensitivity, incretin effects) and (2) tactics for incorporating a measurement of insulin sensitivity in order to adjust insulin secretion measures for insulin sensitivity appropriately. Of particular concern were the capacity to measure ß-cell function accurately in those with poor function, as is seen in established T2D, and the capacity of each method for demonstrating treatment-induced changes in ß-cell function. Feasibility considerations included: staff burden, including time and required methodological expertise; participant burden, including time and number of study visits; and ease of standardizing methods across a multicentre consortium. After this evaluation, we selected a 2-day measurement procedure, combining a 3-hour 75-g oral glucose tolerance test and a 2-stage hyperglycaemic clamp procedure, augmented with arginine.

Imaging of myocardial fatty acid oxidation.

Myocardial fuel selection is a key feature of the health and function of the heart, with clear links between myocardial function and fuel selection and important impacts of fuel selection on ischemia tolerance. Radiopharmaceuticals provide uniquely valuable tools for in vivo, non-invasive assessment of these aspects of cardiac function and metabolism. Here we review the landscape of imaging probes developed to provide non-invasive assessment of myocardial fatty acid oxidation (MFAO). Also, we review the state of current knowledge that myocardial fatty acid imaging has helped establish of static and dynamic fuel selection that characterizes cardiac and cardiometabolic disease and the interplay between fuel selection and various aspects of cardiac function. This article is part of a Special Issue entitled: Heart Lipid Metabolism edited by G.D. Lopaschuk.