Continuous Glucose Monitoring and the Effect of Liraglutide in Cardiac Surgery Patients: A Substudy of the Randomized Controlled GLOBE Trial.

OBJECTIVES: The objectives of the current research were to evaluate the accuracy and reliability of continuous glucose monitoring (CGM) in patients undergoing cardiac surgery and assess the impact of preoperative liraglutide administration on perioperative glucose control as captured by CGM. DESIGN: This was a prospective, single-center, prespecified analysis of the GLOBE trial, a randomized controlled trial comparing preoperative liraglutide treatment to placebo in patients undergoing cardiac surgery. SETTING: The work took place at a single-center academic hospital in the Netherlands. PARTICIPANTS: Twenty-five patients undergoing cardiac surgery were recruited from the hospital's cardiac surgery department. INTERVENTIONS: Participants received the Dexcom G5 CGM system from the day before surgery until discharge from the intensive care unit after surgery. Additionally, participants were randomized to receive either preoperative liraglutide or placebo. MEASUREMENTS AND MAIN RESULTS: Arterial blood gas (ABG) glucose measurements were collected as a reference and matched to CGM readings to assess accuracy and reliability. In 240 paired CGM-ABG glucose measurements, the mean absolute relative difference was 14.4 ± 12.5%. Temporary sensor interruption occurred mainly intraoperatively (92% of patients). The median duration of intraoperative sensor interruption was 65 (48-95) minutes. Liraglutide increased glycemic time in range 72% versus 47% in the control group (absolute difference 25%, 95% confidence interval -41.4 to -8.9, p = .004). CONCLUSIONS: Despite intraoperative sensor interruption, CGM seems an accurate method for semi-invasive, real-time assessment of blood glucose levels. CGM can provide a detailed observation of the pre- and postoperative glycemic trajectory, demonstrating increased time in range following perioperative liraglutide treatment compared with placebo.

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.

Bihormonal fully closed-loop system for the treatment of type 1 diabetes: a real-world multicentre, prospective, single-arm trial in the Netherlands.

BACKGROUND: Management of insulin administration for intake of carbohydrates and physical activity can be burdensome for people with type 1 diabetes on hybrid closed-loop systems. Bihormonal fully closed-loop (FCL) systems could help reduce this burden. In this trial, we assessed the long-term performance and safety of a bihormonal FCL system. METHODS: The FCL system (Inreda AP; Inreda Diabetic, Goor, Netherlands) that uses two hormones (insulin and glucagon) was assessed in a 1 year, multicentre, prospective, single-arm intervention trial in adults with type 1 diabetes. Participants were recruited in eight outpatient clinics in the Netherlands. We included adults with type 1 diabetes aged 18-75 years who had been using flash glucose monitoring or continuous glucose monitors for at least 3 months. Study visits were integrated into standard care, usually every three months, to evaluate glycaemic control, adverse events, and person-reported outcomes. The primary endpoint was time in range (TIR; glucose concentration 3·9-10·0 mmol/L) after 1 year. The study is registered in the Dutch Trial Register, NL9578. FINDINGS: Between June 1, 2021, and March 2, 2022, we screened 90 individuals and enrolled 82 participants; 78 were included in the analyses. 79 started the intervention and 71 were included in the 12 month analysis. Mean age was 47.7 (SD 12·4) years and 38 (49%) were female participants. The mean preintervention TIR of participants was 55·5% (SD 17·2). After 1 year of FCL treatment, mean TIR was 80·3% (SD 5·4) and median time below range was 1·36% (IQR 0·80-2·11). Questionnaire scores improved on Problem Areas in Diabetes (PAID) from 30·0 (IQR 18·8-41·3) preintervention to 10·0 (IQR 3·8-21·3; p<0·0001) at 12 months and on World Health Organization-Five Well-Being Index (WHO-5) from 60·0 (IQR 44·0-72·0) preintervention to 76·0 (IQR 60·0-80·0; p<0·0001) at 12 months. Five serious adverse events were reported (one cerebellar stroke, two severe hypoglycaemic, and two hyperglycaemic events). INTERPRETATION: Real-world data obtained in this trial demonstrate that use of the bihormonal FCL system was associated with good glycaemic control in patients who completed 1 year of treatment, and could help relieve these individuals with type 1 diabetes from making treatment decisions and the burden of carbohydrate counting. FUNDING: Inreda Diabetic.

The WHO 2013 oral glucose tolerance test: The utility of isolated glucose measurements - A retrospective cohort study.

OBJECTIVE: The WHO 2013 guidelines recommend screening for gestational diabetes mellitus (GDM) by 3-point oral glucose tolerance test (OGTT). The objective of this retrospective cohort study was to evaluate GDM diagnosed by an isolated high glucose. STUDY DESIGN: We included pregnant women deemed at risk for GDM were offered GDM screening. We examined the records of 1939 consecutively screened pregnancies at two teaching hospitals in Amsterdam during 2016-2020. Using the WHO 2013 diagnostic criteria, we calculated the proportion of GDM cases diagnosed by isolated abnormal glucose values. RESULTS: Among those screened in our high risk cohort, GDM incidence was 31.5%. Of the GDM diagnoses, 57.0% were based on an isolated fasting glucose value, 30.9% based on multiple raised glucose measurements, 7.4% on an isolated raised 2-hour glucose and 4.7% on an isolated raised 1-hour glucose. For 1-hour glucose, the number needed to screen was 67 persons for one additional GDM case. CONCLUSION: The 1-hour glucose in the 3 point OGTT, as suggested by the WHO 2013 guidelines for GDM, contributes only small numbers of GDM cases and a high number needed to screen (67 for 1 additional case in a selective high risk GDM screening strategy), and is likely even less effective in universally screened populations.

Preoperative Glycosylated Haemoglobin Screening to Identify Older Adult Patients with Undiagnosed Diabetes Mellitus-A Retrospective Cohort Study.

More than 25% of older adults in Europe have diabetes mellitus. It is estimated that 45% of patients with diabetes are currently undiagnosed, which is a known risk factor for perioperative morbidity. We investigated whether routine HbA1c screening in older adult patients undergoing surgery would identify patients with undiagnosed diabetes. We included patients aged ≥65 years without a diagnosis of diabetes who visited the preoperative assessment clinic at the Amsterdam University Medical Center and underwent HbA1c screening within three months before surgery. Patients undergoing cardiac surgery were excluded. We assessed the prevalence of undiagnosed diabetes (defined as HbA1c ≥ 48 mmol·mol-1) and prediabetes (HbA1c 39-47 mmol·mol-1). Using a multivariate regression model, we analysed the ability of HbA1c to predict days alive and at home within 30 days after surgery. From January to December 2019, we screened 2015 patients ≥65 years at our clinic. Of these, 697 patients without a diagnosis of diabetes underwent HbA1c screening. The prevalence of undiagnosed diabetes and prediabetes was 3.7% (95%CI 2.5-5.4%) and 42.9% (95%CI 39.2-46.7%), respectively. Preoperative HbA1c was not associated with days alive and at home within 30 days after surgery. In conclusion, we identified a small number of patients with undiagnosed diabetes and a high prevalence of prediabetes based on preoperative HbA1c screening in a cohort of older adults undergoing non-cardiac surgery. The relevance of prediabetes in the perioperative setting is unclear. Screening for HbA1c in older adult patients undergoing non-cardiac surgery does not appear to help predict postoperative outcome.

Continuous glucose monitoring in adults with type 2 diabetes: a systematic review and meta-analysis.

AIMS/HYPOTHESIS: Continuous glucose monitoring (CGM) is increasingly used in the treatment of type 2 diabetes, but the effects on glycaemic control are unclear. The aim of this systematic review and meta-analysis is to provide a comprehensive overview of the effect of CGM on glycaemic control in adults with type 2 diabetes. METHODS: We performed a systematic review using Embase, MEDLINE, Web of Science, Scopus and ClinicalTrials.gov from inception until 2 May 2023. We included RCTs investigating real-time CGM (rtCGM) or intermittently scanned CGM (isCGM) compared with self-monitoring of blood glucose (SMBG) in adults with type 2 diabetes. Studies with an intervention duration <6 weeks or investigating professional CGM, a combination of CGM and additional glucose-lowering treatment strategies or GlucoWatch were not eligible. Change in HbA1c and the CGM metrics time in range (TIR), time below range (TBR), time above range (TAR) and glycaemic variability were extracted. We evaluated the risk of bias using the Cochrane risk-of-bias tool version 2. Data were synthesised by performing a meta-analysis. We also explored the effects of CGM on severe hypoglycaemia and micro- and macrovascular complications. RESULTS: We found 12 RCTs comprising 1248 participants, with eight investigating rtCGM and four isCGM. Compared with SMBG, CGM use (rtCGM or isCGM) led to a mean difference (MD) in HbA1c of -3.43 mmol/mol (-0.31%; 95% CI -4.75, -2.11, p<0.00001, I2=15%; moderate certainty). This effect was comparable in studies that included individuals using insulin with or without oral agents (MD -3.27 mmol/mol [-0.30%]; 95% CI -6.22, -0.31, p=0.03, I2=55%), and individuals using oral agents only (MD -3.22 mmol/mol [-0.29%]; 95% CI -5.39, -1.05, p=0.004, I2=0%). Use of rtCGM showed a trend towards a larger effect (MD -3.95 mmol/mol [-0.36%]; 95% CI -5.46 to -2.44, p<0.00001, I2=0%) than use of isCGM (MD -1.79 mmol/mol [-0.16%]; 95% CI -5.28, 1.69, p=0.31, I2=64%). CGM was also associated with an increase in TIR (+6.36%; 95% CI +2.48, +10.24, p=0.001, I2=9%) and a decrease in TBR (-0.66%; 95% CI -1.21, -0.12, p=0.02, I2=45%), TAR (-5.86%; 95% CI -10.88, -0.84, p=0.02, I2=37%) and glycaemic variability (-1.47%; 95% CI -2.94, -0.01, p=0.05, I2=0%). Three studies reported one or more events of severe hypoglycaemia and macrovascular complications. In comparison with SMBG, CGM use led to a non-statistically significant difference in the incidence of severe hypoglycaemia (RR 0.66, 95% CI 0.15, 3.00, p=0.57, I2=0%) and macrovascular complications (RR 1.54, 95% CI 0.42, 5.72, p=0.52, I2=29%). No trials reported data on microvascular complications. CONCLUSIONS/INTERPRETATION: CGM use compared with SMBG is associated with improvements in glycaemic control in adults with type 2 diabetes. However, all studies were open label. In addition, outcome data on incident severe hypoglycaemia and incident microvascular and macrovascular complications were scarce. REGISTRATION: This systematic review was registered on PROSPERO (ID CRD42023418005).

Fetal and post-natal outcomes in offspring after intrauterine metformin exposure: A systematic review and meta-analysis of animal experiments.

AIMS: The impact of maternal metformin use during pregnancy on fetal, infant, childhood and adolescent growth, development, and health remains unclear. Our objective was to systematically review the available evidence from animal experiments on the effects of intrauterine metformin exposure on offspring's anthropometric, cardiovascular and metabolic outcomes. METHODS: A systematic search was conducted in PUBMED and EMBASE from inception (searched on 12th April 2023). We extracted original, controlled animal studies that investigated the effects of maternal metformin use during pregnancy on offspring anthropometric, cardiovascular and metabolic measurements. Subsequently, risk of bias was assessed and meta-analyses using the standardized mean difference and a random effects model were conducted for all outcomes containing data from 3 or more studies. Subgroup analyses were planned for species, strain, sex and type of model in the case of 10 comparisons or more per subgroup. RESULTS: We included 37 articles (n = 3133 offspring from n = 716 litters, containing n = 51 comparisons) in this review, mostly (95%) on rodent models and 5% pig models. Follow-up of offspring ranged from birth to 2 years of age. Thirty four of the included articles could be included in the meta-analysis. No significant effects in the overall meta-analysis of metformin on any of the anthropometric, cardiovascular and metabolic offspring outcome measures were identified. Between-studies heterogeneity was high, and risk of bias was unclear in most studies as a consequence of poor reporting of essential methodological details. CONCLUSION: This systematic review was unable to establish effects of metformin treatment during pregnancy on anthropometric, cardiovascular and metabolic outcomes in non-human offspring. Heterogeneity between studies was high and reporting of methodological details often limited. This highlights a need for additional high-quality research both in humans and model systems to allow firm conclusions to be established. Future research should include focus on the effects of metformin in older offspring age groups, and on outcomes which have gone uninvestigated to date.

Continuous glucose monitoring metrics and pregnancy outcomes in insulin-treated diabetes: A post-hoc analysis of the GlucoMOMS trial.

AIM: To investigate the association between continuous glucose monitoring (CGM) metrics and perinatal outcomes in insulin-treated diabetes mellitus in pregnancy. MATERIALS AND METHODS: In a post-hoc analysis of the GlucoMOMS randomized controlled trial, we investigated the association between the metrics of an offline, intermittent CGM, glycated haemoglobin (HbA1c) and perinatal outcomes per trimester in different types of diabetes (type 1, 2 or insulin-treated gestational diabetes mellitus [GDM]). Data were analysed using multivariable binary logistic regression. Outcomes of interest were neonatal hypoglycaemia, pre-eclampsia, preterm birth, large for gestational age (LGA) and Neonatal Intensive Care Unit (NICU) admission. The glucose target range was defined as 3.5-7.8 mmol/L (63-140 mg/dL). RESULTS: Of the 147 participants (N = 50 type 1 diabetes, N = 94 type 2 diabetes/insulin-treated GDM) randomized to the CGM group of the GlucoMOMS trial, 115 participants had CGM metrics available and were included in the current study. We found that, in pregnancies with type 1 diabetes, a higher second trimester mean glucose was associated with LGA (odds ratio 2.6 [95% confidence interval 1.1-6.2]). In type 2 and insulin-treated gestational diabetes, an increased area under the curve above limit was associated with LGA (odds ratio 10.0 [95% confidence interval 1.4-72.8]). None of the CGM metrics were associated with neonatal hypoglycaemia, pre-eclampsia, shoulder dystocia, preterm birth and NICU admission rates for pregnancies complicated by any type of diabetes. CONCLUSION: In this study, in type 2 diabetes or insulin-treated GDM, the glucose increased area under the curve above limit was associated with increased LGA. In type 1 diabetes, the mean glucose was the major determinant of LGA. Our study found no evidence that other CGM metrics determined adverse pregnancy outcomes.

Dual hormone fully closed loop in type 1 diabetes: a randomised trial in the Netherlands - study protocol.

INTRODUCTION: The management of type 1 diabetes (T1DM) has undergone significant advancements with the availability of novel technologies, notably continuous and flash glucose monitoring (CGM and FGM, respectively) and hybrid closed loop (HCL) therapy. The dual hormone fully closed loop (DHFCL) approach with insulin and glucagon infusion has shown promising effects in small studies on glycaemic regulation and quality of life in T1DM. METHODS AND ANALYSIS: The Dual Hormone Fully Closed Loop for Type 1 Diabetes (DARE) study is a non-commercial 12-month open-label, two-arm randomised parallel-group trial. The primary aim of this study is to determine the long-term effects on glycaemic control, patient-reported outcome measurements and cost-effectiveness of the DHFCL compared with usual care, that is, HCL or treatment with multiple daily insulin injections+FGM/CGM. We will include 240 adult patients with T1DM in 14 hospitals in the Netherlands. Individuals will be randomised 1:1 to the DHFCL or continuation of their current care. ETHICS AND DISSEMINATION: Ethical approval has been obtained from the Medical Research Ethics Committee NedMec, Utrecht, the Netherlands. Findings will be disseminated through peer-reviewed publications and presentations at local, national and international conferences. TRIAL REGISTRATION NUMBER: NCT05669547.

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.

Comparison of Postoperative Neurocognitive Function in Older Adult Patients with and without Diabetes Mellitus.

INTRODUCTION: Delayed neurocognitive recovery (DNR; neurocognitive disorder up to 30 days postoperative) and postoperative neurocognitive disorders (POCD; neurocognitive disorder 1-12 months postoperative) occur frequently after surgery, with diabetes mellitus (DM) suggested to contribute to this. This was a single-center prospective cohort study. The main aim of this study was to investigate the role of DM and preoperative hemoglobin A1c (HbA1c) in the development of POCDs after noncardiac surgery. METHODS: Older adult patients ≥65 years of age scheduled for elective surgery were recruited. The Modified Telephone Interview for Cognitive Status questionnaire (TICS-M), a test of global cognitive functioning, was administered to determine cognition. Preoperative, 30-day postoperative, and 6-month postoperative cognition were compared for patients with and without DM. Cognitive decline was subdivided into mild (1 to 2 standard deviations below controls) and major (≥2 standard deviations below controls) DNR or POCD. Preoperative HbA1c levels were correlated with TICS-M scores. RESULTS: We analyzed 102 patients [median (IQR [range]) age 72.0 (5 [68-74])]), who were divided into patients with DM (80 patients [78%]) and patients without DM (22 patients [22%]). Baseline cognitive function was similar for both groups. Repeated measures ANOVA showed that mean DM patient TICS-M scores decreased 30 days postoperative (F(2, 200) = 4.0, p = 0.02), with subsequent recovery 6-month postoperative, compared to stable TICS-M scores in non-DM patients. There were significantly more DM patients with DNR than non-DM patients (n = 11 [50%] vs. n = 14 [17.5%]; p = 0.031). There were no between-group differences in mild or major POCD. Higher preoperative HbA1c levels were significantly correlated with decreased 30-day Δcognition scores (F(1, 54) = 9.4, p = 0.003) with an R2 of 0.149 (ß -0.45, 95% confidence interval: -0.735 to -0.154). CONCLUSIONS: Older adult patients with DM undergoing surgery have an increased risk of DNR compared to older adult non-DM patients, but no increased risk of POCD. In DM patients, higher preoperative HbA1c levels were associated with an increased risk of DNR.

Type 1 and other types of diabetes mellitus in the perioperative period. What the anaesthetist should know.

Diabetes mellitus is often treated as a uniform disease in the perioperative period. Type 2 diabetes is most commonly encountered, and only a minority of surgical patients have been diagnosed with another type of diabetes. Patients with a specific type of diabetes can be particularly prone to perioperative glycaemic dysregulation. In addition, certain type-related features and pitfalls should be taken into account in the operating theatre. In this narrative review, we discuss characteristics of types of diabetes other than type 2 diabetes relevant to the anaesthetist, based on available literature and data from our clinic.

Consensus Recommendations for the Use of Automated Insulin Delivery Technologies in Clinical Practice.

The significant and growing global prevalence of diabetes continues to challenge people with diabetes (PwD), healthcare providers, and payers. While maintaining near-normal glucose levels has been shown to prevent or delay the progression of the long-term complications of diabetes, a significant proportion of PwD are not attaining their glycemic goals. During the past 6 years, we have seen tremendous advances in automated insulin delivery (AID) technologies. Numerous randomized controlled trials and real-world studies have shown that the use of AID systems is safe and effective in helping PwD achieve their long-term glycemic goals while reducing hypoglycemia risk. Thus, AID systems have recently become an integral part of diabetes management. However, recommendations for using AID systems in clinical settings have been lacking. Such guided recommendations are critical for AID success and acceptance. All clinicians working with PwD need to become familiar with the available systems in order to eliminate disparities in diabetes quality of care. This report provides much-needed guidance for clinicians who are interested in utilizing AIDs and presents a comprehensive listing of the evidence payers should consider when determining eligibility criteria for AID insurance coverage.

Bihormonal Artificial Pancreas With Closed-Loop Glucose Control vs Current Diabetes Care After Total Pancreatectomy: A Randomized Clinical Trial.

Importance: Glucose control in patients after total pancreatectomy is problematic because of the complete absence of α- and ß-cells, leading to impaired quality of life. A novel, bihormonal artificial pancreas (BIHAP), using both insulin and glucagon, may improve glucose control, but studies in this setting are lacking. Objective: To assess the efficacy and safety of the BIHAP in patients after total pancreatectomy. Design, Setting, and Participants: This randomized crossover clinical trial compared the fully closed-loop BIHAP with current diabetes care (ie, insulin pump or pen therapy) in 12 adult outpatients after total pancreatectomy. Patients were recruited between August 21 and November 16, 2020. This first-in-patient study began with a feasibility phase in 2 patients. Subsequently, 12 patients were randomly assigned to 7-day treatment with the BIHAP (preceded by a 5-day training period) followed by 7-day treatment with current diabetes care, or the same treatments in reverse order. Statistical analysis was by Wilcoxon signed rank and Mann-Whitney U tests, with significance set at a 2-sided P < .05. Main Outcomes and Measures: The primary outcome was the percentage of time spent in euglycemia (70-180 mg/dL [3.9-10 mmol/L]) as assessed by continuous glucose monitoring. Results: In total, 12 patients (7 men and 3 women; median [IQR] age, 62.5 [43.1-74.0] years) were randomly assigned, of whom 3 did not complete the BIHAP phase and 1 was replaced. The time spent in euglycemia was significantly higher during treatment with the BIHAP (median, 78.30%; IQR, 71.05%-82.61%) than current diabetes care (median, 57.38%; IQR, 52.38%-81.35%; P = .03). In addition, the time spent in hypoglycemia (<70 mg/dL [3.9 mmol/L]) was lower with the BIHAP (median, 0.00% [IQR, 0.00%-0.07%] vs 1.61% [IQR, 0.80%-3.81%]; P = .004). No serious adverse events occurred. Conclusions and Relevance: Patients using the BIHAP after total pancreatectomy experienced an increased percentage of time in euglycemia and a reduced percentage of time in hypoglycemia compared with current diabetes care, without apparent safety risks. Larger randomized trials, including longer periods of treatment and an assessment of quality of life, should confirm these findings. Trial Registration: trialregister.nl Identifier: NL8871.

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.