Triple hormone receptor agonist retatrutide for metabolic dysfunction-associated steatotic liver disease: a randomized phase 2a trial.

Retatrutide is a novel triple agonist of the glucose-dependent insulinotropic polypeptide, glucagon-like peptide 1 and glucagon receptors. A 48-week phase 2 obesity study demonstrated weight reductions of 22.8% and 24.2% with retatrutide 8 and 12 mg, respectively. The primary objective of this substudy was to assess mean relative change from baseline in liver fat (LF) at 24 weeks in participants from that study with metabolic dysfunction-associated steatotic liver disease and ≥10% of LF. Here, in this randomized, double-blind, placebo-controlled trial, participants (n = 98) were randomly assigned to 48 weeks of once-weekly subcutaneous retatrutide (1, 4, 8 or 12 mg dose) or placebo. The mean relative change from baseline in LF at 24 weeks was -42.9% (1 mg), -57.0% (4 mg), -81.4% (8 mg), -82.4% (12 mg) and +0.3% (placebo) (all P < 0.001 versus placebo). At 24 weeks, normal LF (<5%) was achieved by 27% (1 mg), 52% (4 mg), 79% (8 mg), 86% (12 mg) and 0% (placebo) of participants. LF reductions were significantly related to changes in body weight, abdominal fat and metabolic measures associated with improved insulin sensitivity and lipid metabolism. The ClinicalTrials.gov registration is NCT04881760 .

Effects of Tirzepatide vs Semaglutide on ß-cell Function, Insulin Sensitivity, and Glucose Control During a Meal Test.

CONTEXT: In a clinical study, tirzepatide, a glucose-dependent insulinotropic polypeptide/glucagon-like peptide-1 receptor agonist (GIP/GLP-1RA), provided superior glycemic control vs the GLP-1RA semaglutide. The physiologic mechanisms are incompletely understood. OBJECTIVE: To evaluate treatment effects by model-based analyses of mixed-meal tolerance test (MMTT) data. DESIGN: A 28-week double-blind, randomized, placebo-controlled trial. SETTING: Two clinical research centers in Germany. PATIENTS: Patients with type 2 diabetes treated with metformin. INTERVENTIONS: Tirzepatide 15 mg, semaglutide 1 mg, placebo. MAIN OUTCOME MEASURES: Glycemic control, model-derived ß-cell function indices including insulin secretion rate (ISR) at 7.2-mmol/L glucose (ISR7.2), ß-cell glucose (ß-CG) sensitivity, insulin sensitivity, and estimated hepatic insulin-to-glucagon ratio. RESULTS: Tirzepatide significantly reduced fasting glucose and MMTT total glucose area under the curve (AUC) vs semaglutide (P < 0.01). Incremental glucose AUC did not differ significantly between treatments; therefore, greater total glucose AUC reduction with tirzepatide was mainly attributable to greater suppression of fasting glucose. A greater reduction in total ISR AUC was achieved with tirzepatide vs semaglutide (P < 0.01), in the context of greater improvement in insulin sensitivity with tirzepatide (P < 0.01). ISR7.2 was significantly increased with tirzepatide vs semaglutide (P < 0.05), showing improved ß-CG responsiveness. MMTT-derived ß-CG sensitivity was increased but not significantly different between treatments. Both treatments reduced fasting glucagon and total glucagon AUC, with glucagon AUC significantly reduced with tirzepatide vs semaglutide (P < 0.01). The estimated hepatic insulin-to-glucagon ratio did not change substantially with either treatment. CONCLUSIONS: These results suggest that the greater glycemic control observed for tirzepatide manifests as improved fasting glucose and glucose excursion control, due to improvements in ISR, insulin sensitivity, and glucagon suppression.

Predictors of glycemic worsening in the next year in adults with screen-detected type 2 diabetes.

Background and Aims: Identifying simple markers of risk for worsening glucose can allow care providers to target therapeutic interventions according to risk of worsening glycemic control. We aimed to determine which routine clinical measures herald near-term glycemic worsening in early type 2 diabetes(T2D). Methods: The Early Diabetes Intervention Program (EDIP) was a clinical trial in individuals with screendetected T2D [HbA1C 6.3+0.63%(45+5mmol/mol)]. During the trial some participants experienced worsening fasting blood glucose (FBG). We investigated the time course of FBG, HbA1c, weight, and other clinical factors to determine which might herald glycemic worsening over the next year. Results: Progressors (62/219, 28.5%) had higher FBG than non-progressors at baseline [118 vs 130mg/dL (6.6 vs 7.2 mmol/L), p=<0.001]. FBG was stable except in the year of progression, when progressors exhibited a large 1-year rise [mean change 14.2mg/dL(0.79 mmol/L)]. Current FBG and antecedent year change in FBG were associated with progression(p<0.01), although the magnitude of change was too small to be of clinical utility (0.19 mg/dL; 0.01 mmol/L). Current or antecedent year change in HbA1c, weight, TG or HDL were not associated with progression. In the year of glycemic worsening, rising glucose was strongly associated with a concurrent increase in weight (p<0.001). Conclusions: Elevated FBG but not HbA1c identified individuals at risk for imminent glycemic worsening; the subsequent large rise in glucose was associated with a short-term increase in weight. Glucose and weight surveillance provide actionable information for those caring for patients with early diabetes.

Program ACTIVE II: 6- and 12-month outcomes of a treatment approach for major depressive disorder in adults with type 2 diabetes.

AIMS: To evaluate the long-term effects of behavioral treatments on glycemic and psychological outcomes for patients with major depressive disorder (MDD) and type 2 diabetes (T2D). METHODS: Program ACTIVE II was a multicenter randomized controlled comparative effectiveness trial of cognitive behavioral therapy (CBT), exercise (EXER), combination treatment (CBT + EXER) and usual care (UC) for adults with MDD and T2D. RESULTS: Primary outcomes: change in A1c and depressive symptoms at 6- (N = 87) and 12-months (N = 75) from baseline. In those with a baseline A1c ≥7.0 %, CBT + EXER showed lasting A1c benefit at 6- (-1.2 %; SE: 0.6; p = 0.032) and 12-months (-1.4 %; SE: 0.6; p = 0.025) compared to UC. All groups had clinically significant improvements in depressive symptoms. At 6 months, CBT + EXER had significant improvements in diabetes-related distress regimen burden (p = 0.005); and social support (CIRS, p = 0.043) compared to UC. CONCLUSIONS: The Program ACTIVE II CBT + EXER intervention demonstrated a sustained improvement in A1c for a subgroup of study participants with a baseline A1c ≥7.0 %. However, this finding should be considered preliminary because of small sample size. All 3 behavioral intervention groups demonstrated improvements in psychosocial outcomes one-year post-intervention. These findings point to the enduring benefits of community-based interventions to extend the availability of depression treatment for T2D patients.

Selective Collection of Exhaled Breath Condensate for Noninvasive Screening of Breath Glucose.

BACKGROUND: Although exhaled breath condensate (EBC) is a promising noninvasive sample for detecting respiratory analytes such as glucose, current EBC collection methods yield inconsistent results. METHODS: We developed a custom EBC collection device with a temperature-based algorithm to selectively condense alveolar air for reproducible EBC glucose detection. We characterized the condensate volumes and the corresponding glucose concentrations. We performed a pilot study demonstrating its use during oral glucose tolerance tests. RESULTS: The novel device selectively captured alveolar air resulting in slightly higher and less variable glucose concentrations than the overall EBC. Participants with type 2 diabetes demonstrated significantly higher blood plasma-EBC glucose ratios than normoglycemic participants. CONCLUSIONS: Temperature-based selective EBC collection allows EBC glucose measurement and is a promising sampling method to distinguish patients with and without diabetes.

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.

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.).

Tirzepatide Reduces Appetite, Energy Intake, and Fat Mass in People With Type 2 Diabetes.

OBJECTIVE: To evaluate the effects of tirzepatide on body composition, appetite, and energy intake to address the potential mechanisms involved in body weight loss with tirzepatide. RESEARCH DESIGN AND METHODS: In a secondary analysis of a randomized, double-blind, parallel-arm study, the effects of tirzepatide 15 mg (N = 45), semaglutide 1 mg (N = 44), and placebo (N = 28) on body weight and composition, appetite, and energy intake were assessed at baseline and week 28. RESULTS: Tirzepatide treatment demonstrated significant reductions in body weight compared with placebo and semaglutide, resulting in greater fat mass reduction. Tirzepatide and semaglutide significantly reduced appetite versus placebo. Appetite scores and energy intake reductions did not differ between tirzepatide and semaglutide. CONCLUSIONS: Differences in energy intake during ad libitum lunch were not sufficient to explain the different weight outcomes. Further evaluation is needed to assess mechanistic differences related to tirzepatide actions on 24-h energy intake, substrate utilization, and energy expenditure.

Reproducibility of Glycemic Measures Among Dysglycemic Youth and Adults in the RISE Study.

AIMS: Previous work found poor reproducibility for measures of glycemia in individuals at risk for dysglycemia. Differences between youth and adults have not been assessed. Using youth and adults in the Restoring Insulin Secretion Study, we tested variability and classification concordance for hemoglobin A1C (HbA1c), fasting and 2-hour glucose from oral glucose tolerance tests (OGTTs). METHODS: HbA1c and glucose on repeated samples obtained ∼6 weeks apart were compared in 66 youth (mean age 14.2 years) and 354 adults (52.7 years). Changes, coefficient of variation (CV), and concordance of diagnostic categories between the 2 visits were compared. RESULTS: Mean difference between the 2 visits in HbA1c was higher in youth than adults (P < .001), while fasting glucose was similar and 2-hour glucose was lower in youth (P = .051). CV was smallest for HbA1c compared to fasting and 2-hour glucose. For HbA1c, youth had higher CV (P < .001); whereas CV for 2-hour glucose was lower for youth (P = .041). Classification concordance by HbA1c was lower in youth (P = .004). Using OGTT or HbA1c for classification, intervisit variability produced discordant classification in 20% of youth and 28% of adults. Using both fasting glucose and HbA1c, intervisit variability reduced discordant classification to 16% of adults while not improving classification in youth. CONCLUSIONS: Poor reproducibility and lack of classification concordance highlight the limitations of one-time testing, with important implications for assessing eligibility in clinical trials. Consideration should be given to using more than a single parameter for screening and diagnosis, especially when classification category is important.

Discovery, development, and clinical proof of mechanism of LY3463251, a long-acting GDF15 receptor agonist.

GDF15 and its receptor GFRAL/RET form a non-homeostatic system that regulates food intake and body weight in preclinical species. Here, we describe a GDF15 analog, LY3463251, a potent agonist at the GFRAL/RET receptor with prolonged pharmacokinetics. In rodents and obese non-human primates, LY3463251 decreased food intake and body weight with no signs of malaise or emesis. In a first-in-human study in healthy participants, single subcutaneous LY3463251 injections showed a safety and pharmacokinetic profile supporting further clinical development with dose-dependent nausea and emesis in a subset of individuals. A subsequent 12-week multiple ascending dose study in overweight and obese participants showed that LY3463251 induced significant decreases in food intake and appetite scores associated with modest body weight reduction independent of nausea and emesis (clinicaltrials.gov: NCT03764774). These observations demonstrate that agonism of the GFRAL/RET system can modulate energy balance in humans, though the decrease in body weight is surprisingly modest, suggesting challenges in leveraging the GDF15 system for clinical weight-loss applications.

Weight loss and ß-cell responses following gastric banding or pharmacotherapy in adults with impaired glucose tolerance or type 2 diabetes: a randomized trial.

OBJECTIVE: The extent to which weight loss contributes to increases in insulin sensitivity (IS) and ß-cell function after surgical or medical intervention has not been directly compared in individuals with impaired glucose tolerance or newly diagnosed type 2 diabetes. METHODS: The Restoring Insulin Secretion (RISE) Study included adults in the Beta-Cell Restoration Through Fat Mitigation Study (n = 88 randomized to laparoscopic gastric banding or metformin [MET]) and the Adult Medication Study (n = 267 randomized to placebo, MET, insulin glargine/MET, or liraglutide + MET [L + M]). IS and ß-cell responses were measured at baseline and after 12 months by modeling of oral glucose tolerance tests and during arginine-stimulated hyperglycemic clamps. Linear regression models assessed differences between and within treatments over time. RESULTS: BMI decreased in all treatment groups, except placebo, at 12 months. IS increased in all arms except placebo and was inversely correlated with changes in BMI. L + M was the only treatment arm that enhanced multiple measures of ß-cell function independent of weight loss. Insulin secretion decreased in the laparoscopic gastric banding arm proportional to increases in IS, with no net benefit on ß-cell function. CONCLUSIONS: Reducing demand on the ß-cell by improving IS through weight loss does not reverse ß-cell dysfunction. L + M was the only treatment that enhanced ß-cell function.

Acute SGLT-2i treatment improves cardiac efficiency during myocardial ischemia independent of Na+/H+ exchanger-1.

AIMS: Sodium glucose co-transporter 2 inhibitors (SGLT2i) demonstrate cardioprotective benefits independent of a glucose lowering effect including preservation of cardiac function during a myocardial ischemia. Sodium­hydrogen exchanger-1 (NHE-1), has been hypothesized to contribute to the cardiac effects of SGLT2i. We characterized the beneficial effects of acute pre-ischemia exposure to SGLT2i and explored the possibility that these effects are explained by NHE-1 inhibition. METHODS AND RESULTS: Swine were anesthetized and instrumented for invasive hemodynamic measurements. After baseline data collection, swine received a 15-30 min intravenous infusion of vehicle (DMSO), the SGLT2i canagliflozin (~1 mg/kg), or the NHE-1 inhibitor cariporide (~0.03 mg/kg) ending immediately prior to occlusion of the left circumflex artery. Measurements were obtained at baseline, during a 60-min complete occlusion of the circumflex coronary artery, and during a 2-h reperfusion period. Blood pressure, heart rate, left anterior descending artery flow, and associated myocardial oxygen consumption were unaffected by acute pre-treatment with canagliflozin or cariporide during ischemia and reperfusion. Acute pre-ischemic treatment with canagliflozin significantly increased diastolic filling and stroke work, producing a rightward shift in the Frank-Starling relationship, and also improved cardiac work efficiency relative to untreated control hearts during ischemia. Effects of NHE-1 inhibition with cariporide were modest and dissimilar. Examination of AP-1 cells transfected with wild-type NHE-1 and iPSC-derived cardiomyocytes confirmed dose-dependent-inhibition of NHE-1 activity by cariporide, while canagliflozin had no significant effect on NHE-1 activity. CONCLUSION: Acute pre-treatment with SGLT2i produces cardioprotective effects during ischemia, including improved work efficiency. These effects are not explained by NHE-1 inhibition. TRANSLATIONAL PERSPECTIVE: SGLT2 inhibitors have been shown to improve cardiac outcomes in patient including reducing myocardial infarction incidence and mortality. The mechanism(s) explaining this effect are not clear. This manuscript demonstrates a protective effect from acute SGLT2i exposure, as short as 15 min, prior to experimental infarction in swine. These effects were independent of NHE1 inhibition. These observations suggest that SGLT2 inhibitors can confer cardioprotective effects on a very short time scale. It is possible that such effects provide an ongoing contribution to ischemic protection even in the setting of chronic treatment.

An Early Assessment of the Real-World Treatment Patterns of Type 2 Diabetes: A Comparison to the 2018 ADA/EASD Consensus Report Recommendations.

INTRODUCTION: Using the American Diabetes Association (ADA) Hyperglycemic Pharmacotherapy Guidelines for type 2 diabetes, we evaluated the medication use patterns in real-world patients with type 2 diabetes in the USA. METHODS: Health care claims among patients with type 2 diabetes were analyzed (IBM® MarketScan® 2007 to 2019 Commercial and Medicare Databases). Diabetes treatment patterns were evaluated for the total patient sample of 580,741 during the year 2019. Prior years' claims data were used to construct patient history and determine clinical groups per the 2018 ADA/EASD consensus statement: atherosclerotic cardiovascular disease (ASCVD), chronic kidney disease (CKD), heart failure (HF), hypoglycemia (hypo), and obesity. The recommended therapy use rates (RTUR) were calculated for clinical groups. Univariate chi-square tests were performed to compare RTUR within and outside clinical groups. Multivariate logistic regression was used to identify variables associated with recommended therapy use. RESULTS: A large proportion of patients belonged to multiple clinical groups; this was more common in the Medicare cohort. Each clinical group in the Commercial cohort had a substantially higher RTUR than in the Medicare cohort. However, no clinical group achieved > 40% RTUR. The RTUR was the highest in the CKD and obesity groups in the Commercial cohort and in the hypo and obesity groups in the Medicare cohort, but lowest in hypo and HF groups in the Commercial and Medicare cohorts, respectively. CONCLUSION: Prevalence of guideline-aligned treatment use in 2019 was low, particularly since many patients fit into multiple risk groups with established treatment benefits.

Effects of subcutaneous tirzepatide versus placebo or semaglutide on pancreatic islet function and insulin sensitivity in adults with type 2 diabetes: a multicentre, randomised, double-blind, parallel-arm, phase 1 clinical trial.

BACKGROUND: Tirzepatide, a dual glucose-dependent insulinotropic polypeptide (GIP)/GLP-1 receptor agonist, shows a remarkable ability to lower blood glucose, enabling many patients with long-standing type 2 diabetes to achieve normoglycaemia. We aimed to understand the physiological mechanisms underlying the action of tirzepatide in type 2 diabetes. METHODS: This multicentre, randomised, double-blind, parallel-arm, phase 1 study was done at two centres in Germany. Eligible patients were aged 20-74 years, had type 2 diabetes for at least 6 months, and were being treated with lifestyle advice and stable doses of metformin, with or without one additional stable dose of another oral antihyperglycaemic medicine, 3 months before study entry. Via a randomisation table, patients were randomly assigned (3:3:2) to subcutaneously receive either tirzepatide 15 mg, semaglutide 1 mg, or placebo once per week. Endpoint measurements were done at baseline and the last week of therapy (week 28). The primary endpoint was the effect of tirzepatide versus placebo on the change in clamp disposition index (combining measures of insulin secretion and sensitivity) from baseline to week 28 of treatment and was analysed in the pharmacodynamic analysis set, which comprised all randomly assigned participants who received at least one dose of a study drug and had evaluable pharmacodynamic data. Safety was analysed in the safety population, which comprised all randomly assigned participants who received at least one dose of a study drug. Secondary endpoints included the effect of tirzepatide versus semaglutide on the change in clamp disposition index from baseline to week 28 of treatment, glucose control, total insulin secretion rate, M value (insulin sensitivity), and fasting and postprandial glucagon concentrations. Exploratory endpoints included the change in fasting and postprandial insulin concentrations. This study is registered with ClinicalTrials.gov, NCT03951753, and is complete. FINDINGS: Between June 28, 2019, and April 8, 2021, we screened 184 individuals and enrolled 117 participants, all of whom were included in the safety population (45 in the tirzepatide 15 mg group, 44 in the semaglutide 1 mg group, and 28 in the placebo group). Because of discontinuations and exclusions due to missing or unevaluable data, 39 patients in each treatment group and 24 patients in the placebo group comprised the pharmacodynamic analysis set. With tirzepatide, the clamp disposition index increased from a least squares mean of 0·3 pmol m-2 L min-2 kg-1 (SE 0·03) at baseline by 1·9 pmol m-2 L min-2 kg-1 (0·16) to total 2·3 pmol m-2 L min-2 kg-1 (SE 0·16) at week 28 and, with placebo, the clamp disposition index did not change much from baseline (least squares mean at baseline 0·4 pmol m-2 L min-2 kg-1 [SE 0·04]; change from baseline 0·0 pmol m-2 L min-2 kg-1 [0·03]; least squares mean at week 28 0·3 [SE 0·03]; estimated treatment difference [ETD] tirzepatide vs placebo 1·92 [95% CI 1·59-2·24]; p<0·0001). The improvement with tirzepatide in clamp disposition index was significantly greater than with semaglutide (ETD 0·84 pmol m-2 L min-2 kg-1 [95% CI 0·46-1·21]). This result reflected significant improvements in total insulin secretion rate (ETD 102·09 pmol min-1 m-2 [51·84-152·33]) and insulin sensitivity (ETD 1·52 mg min-1 kg-1 [0·53-2·52]) for tirzepatide versus semaglutide. On meal tolerance testing, tirzepatide significantly reduced glucose excursions (lower insulin and glucagon concentrations) compared with placebo, with effects on these variables being greater than with semaglutide. The safety profiles of tirzepatide and semaglutide were similar, with gastrointestinal adverse events being the most common (11 [24%], 13 [30%], and seven [25%] with nausea; nine [20%], 13 [30%], and six [21%] with diarrhoea; and three [7%], five [11%], and one [4%] with vomiting, for tirzepatide, semaglutide, and placebo, respectively). There were no deaths. INTERPRETATION: The glycaemic efficacy of GIP/GLP-1 receptor agonist tirzepatide in type 2 diabetes results from concurrent improvements in key components of diabetes pathophysiology, namely ß-cell function, insulin sensitivity, and glucagon secretion. These effects were large and help to explain the remarkable glucose-lowering ability of tirzepatide seen in phase 3 studies. FUNDING: Eli Lilly.

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.

Islet Autoimmunity is Highly Prevalent and Associated With Diminished ß-Cell Function in Patients With Type 2 Diabetes in the Grade Study.

Islet autoimmunity may contribute to ß-cell dysfunction in type 2 diabetes (T2D). Its prevalence and clinical significance have not been rigorously determined. In this ancillary study to the Glycemia Reduction Approaches in Diabetes-A Comparative Effectiveness (GRADE) Study, we investigated the prevalence of cellular and humoral islet autoimmunity in patients with T2D duration 4·0±3·0 y, HbA1c 7·5±0·5% on metformin alone. We measured T cell autoreactivity against islet proteins, islet autoantibodies against GAD65, IA2, ZnT8, and ß-cell function. Cellular islet autoimmunity was present in 41·3%, humoral islet autoimmunity in 13·5%, and both in 5·3%. ß-cell function calculated as iAUC-CG and ΔC-peptide(0- 30)/Δglucose(0-30) from an oral glucose tolerance test was lower among T cell-positives (T+) than T cell-negatives (T-) using two different adjustments for insulin sensitivity (iAUC-CG: 13·2% [95% CI 0·3, 24·4%] or 11·4% [95% CI 0·4, 21·2%] lower; ΔC-peptide(0-30)/Δglucose(0-30)) 19% [95% CI 3·1, 32·3%] or 17·7% [95% CI 2·6, 30·5%] lower). T+ patients had 17% higher HbA1c (95% CI 0·07, 0·28) and 7·7 mg/dL higher fasting plasma glucose levels (95% CI 0·2,15·3) than T- patients. We conclude that islet autoimmunity is much more prevalent in T2D patients than previously reported. T cell-mediated autoimmunity is associated with diminished ß-cell function and worse glycemic control.

Shape of the OGTT glucose response curve: relationship with ß-cell function and differences by sex, race, and BMI in adults with early type 2 diabetes treated with metformin.

INTRODUCTION: The shape of the glucose curve during an oral glucose tolerance test (OGTT) reflects ß-cell function in populations without diabetes but has not been as well studied in those with diabetes. A monophasic shape has been associated with higher risk of diabetes, while a biphasic pattern has been associated with lower risk. We sought to determine if phenotypic or metabolic characteristics were associated with glucose response curve shape in adults with type 2 diabetes treated with metformin alone. RESEARCH DESIGN AND METHODS: This is a cross-sectional analysis of 3108 metformin-treated adults with type 2 diabetes diagnosed <10 years who underwent 2-hour 75 g OGTT at baseline as part of the Glycemia Reduction Approaches in Diabetes: A Comparative Effectiveness Study (GRADE). Insulin sensitivity (homeostasis model of insulin sensitivity, HOMA2-S) and ß-cell function (early, late, and total incremental insulin and C peptide responses adjusted for HOMA2-S) were calculated. Glucose curve shape was classified as monophasic, biphasic, or continuous rise. RESULTS: The monophasic profile was the most common (67.8% monophasic, 5.5% biphasic, 26.7% continuous rise). The monophasic subgroup was younger, more likely male and white, and had higher body mass index (BMI), while the continuous rise subgroup was more likely female and African American/black. HOMA2-S and fasting glucose did not differ among the subgroups. The biphasic subgroup had the highest early, late, and total insulin and C peptide responses (all p<0.05 vs monophasic and continuous rise). Compared with the monophasic subgroup, the continuous rise subgroup had similar early insulin (p=0.3) and C peptide (p=0.6) responses but lower late insulin (p<0.001) and total insulin (p=0.008) and C peptide (p<0.001) responses. CONCLUSIONS: Based on the large multiethnic GRADE cohort, sex, race, age, and BMI were found to be important determinants of the shape of the glucose response curve. A pattern of a continuously rising glucose at 2 hours reflected reduced ß-cell function and may portend increased glycemic failure rates. TRIAL REGISTRATION NUMBER: NCT01794143.

Differential loss of ß-cell function in youth vs. adults following treatment withdrawal in the Restoring Insulin Secretion (RISE) study.

AIMS: To compare OGTT-derived estimates of ß-cell function between youth and adults with impaired glucose tolerance (IGT) or recently diagnosed type 2 diabetes after treatment discontinuation in RISE. METHODS: Youth (n = 89) and adults (n = 132) were randomized to 3 months glargine followed by 9 months metformin (G/M) or 12 months metformin (MET). Insulin sensitivity and ß-cell responses were estimated from 3-hour OGTTs over 21 months. Linear mixed models tested for differences by time and age group within each treatment arm. RESULTS: After treatment withdrawal, HbA1c increased in both youth and adults with a larger net increase in G/M youth vs. adults at 21 months. Among youth, ß-cell function decreased starting at 12 months in G/M and 15 months in MET. Among adults, ß-cell function remained relatively stable although insulin secretion rates decreased in G/M at 21 months. At 21 months vs. baseline ß-cell function declined to a greater extent in youth vs. adults in both the G/M and MET treatment arms. CONCLUSIONS: After treatment withdrawal youth demonstrated progressive decline in ß-cell function after stopping treatment with either G/M or MET. In contrast, ß-cell function in adults remained stable despite an increase in HbA1c over time. ClinicalTrials.gov Identifier: NCT01779375 and NCT01779362 at clinical trials.gov.