Continuous glucose monitoring captures glycemic variability in obesity after sleeve gastrectomy: A prospective cohort study.

Objective: HbA1c is an insensitive marker for assessing real-time dysglycemia in obesity. This study investigated whether 1-h plasma glucose level (1-h PG) ≥155 mg/dL (8.6 mmol/L) during an oral glucose tolerance test (OGTT) and continuous glucose monitoring (CGM) measurement of glucose variability (GV) better reflected dysglycemia than HbA1c after weight loss from metabolic and bariatric surgery. Methods: This was a prospective cohort study of 10 participants with type 2 diabetes compared with 11 participants with non-diabetes undergoing sleeve gastrectomy (SG). At each research visit; before SG, and 6 weeks and 6 months post-SG, body weight, fasting lipid levels, and PG and insulin concentrations during an OGTT were analyzed. Mean amplitude of glycemic excursions (MAGE), a CGM-derived GV index, was analyzed. Results: The 1-h PG correlated with insulin resistance markers, triglyceride/HDL ratio and triglyceride glucose index in both groups before surgery. At 6 months, SG caused 22% weight loss in both groups. Despite a reduction in HbA1c by 3.0 ± 1.3% in the diabetes group (p < 0.01), 1-h PG, and MAGE remained elevated, and the oral disposition index, which represents pancreatic ß-cell function, remained reduced in the diabetes group when compared to the non-diabetes group. Conclusions: Elevation of GV markers and reduced disposition index following SG-induced weight loss in the diabetes group underscores persistent ß-cell dysfunction and the potential residual risk of diabetes complications.

Cohort profile: study design and baseline characteristics of an observational longitudinal weight loss cohort and biorepository of patients undergoing sleeve gastrectomy in the USA.

PURPOSE: We developed a comprehensive sleeve gastrectomy (SG) weight loss study cohort and biorepository to uncover mechanisms, biomarkers and predictive factors of weight loss, weight maintenance and amelioration of obesity-related comorbidities. For this purpose, we collected psychosocial, anthropometric, clinical data and a variety of samples pre-surgery, intraoperatively and 1.5, 3, 12 and 24 months post-surgery. For longer-term assessment, the collection of psychosocial and anthropometric data was extended to 10 years. Here, we present in-depth characterisation of the cohort and detailed overview of study procedures as a foundation for future analyses. PARTICIPANTS: We consented 647 participants between June 2017 and March 2020 from two bariatric surgery clinics in New York City-one major urban hospital and one private hospital. Of 355 participants who provided baseline data, 300 underwent SG. Of these, 79% are females with an average age of 38 years, 68% are Hispanic, 20% are non-Hispanic Black and 11% are non-Hispanic White. FINDINGS TO DATE: We collected intraoperative adipose and stomach tissues from 282 patients and biosamples (blood, urine, saliva, stool) from 245 patients at 1.5 months, 238 at 3 month, 218 at 12 months and 180 at 24 months post-surgery. We are currently collecting anthropometric and psychosocial data annually until 10 years post-surgery. Data analysis is currently underway. FUTURE PLANS: Our future research will explore the variability in weight loss outcomes observed in our cohort, particularly among Black and Hispanic patients in comparison to their White counterparts. We will identify social determinants of health, metabolic factors and other variables that may predict weight loss success, weight maintenance and remission of obesity-related comorbidities. Additionally, we plan to leverage our biorepository for collaborative research studies. We will complete long-term follow-up data by December 2031. We plan to apply for funding to expand biosample collection through year 10 to provide insights into the mechanisms of long-term weight maintenance.

Pilot study of resveratrol in older adults with impaired glucose tolerance.

BACKGROUND: Resveratrol, a plant-derived polyphenol, has shown promising effects on insulin sensitivity and glucose tolerance in animal models and is also reported to have cardioprotective properties, but human studies are limited. In a pilot study, we tested the hypothesis that resveratrol improves glucose metabolism and vascular function in older adults with impaired glucose tolerance (IGT). METHODS: Ten subjects aged 72 ± 3 years (M ± SD) with IGT were enrolled in a 4-week open-label study of resveratrol (daily dose 1, 1.5, or 2 g). Following a standard mixed meal (110 g carbohydrate, 20 g protein, 20 g fat), we measured 3-hour glucose and insulin area under the curve (AUC), insulin sensitivity (Matsuda index), and secretion (corrected insulin response at 30 minutes). Endothelial function was assessed by reactive hyperemia peripheral arterial tonometry (reactive hyperemia index) before and 90 minutes postmeal. Results did not differ by dose, so data were combined for analysis. RESULTS: At baseline, body mass index was 29 ± 5 kg/m(2), fasting plasma glucose 110 ± 13 mg/dL, and 2-hour glucose 183 ± 33 mg/dL. After 4 weeks of resveratrol, fasting plasma glucose was unchanged, but peak postmeal (185 ± 10 vs 166 ± 9 mg/dL, p = .003) and 3-hour glucose AUC (469 ± 23 vs 428 ± 19, p = .001) declined. Matsuda index improved (3.1 ± 0.5 vs 3.8 ± 0.5, p = .03), and corrected insulin response at 30 minutes was unchanged (0.6 ± 0.1 vs 0.5 ± 0.5, p = .49). There was a trend toward improved postmeal reactive hyperemia index (baseline vs resveratrol postmeal delta -0.4 ± 0.2 vs 0.2 ± 0.3, p = .06). Weight, blood pressure, and lipids were unchanged. CONCLUSIONS: At doses between 1 and 2 g/day, resveratrol improves insulin sensitivity and postmeal plasma glucose in subjects with IGT. These preliminary findings support the conduct of larger studies to further investigate the effects of resveratrol on metabolism and vascular function.

Post-challenge hyperglycemia in older adults is associated with increased cardiovascular risk profile.

CONTEXT: Post-challenge hyperglycemia (PCH) is common in older adults and is associated with increased cardiovascular disease (CVD) risk and total mortality. However, PCH is rarely recognized in clinical settings, and the glycemic exposure and CVD risk profile of elderly individuals with PCH has not been defined. OBJECTIVE: The aim of the study was to characterize metabolic and CVD risk profile of elderly subjects with PCH and to determine the effect of acute postprandial metabolic changes on vascular biomarkers. DESIGN: We conducted a cross-sectional study with a standard meal challenge protocol. PARTICIPANTS: Older adults with normal glucose tolerance (n = 30) or PCH (fasting glucose <126 mg/dl and 2-h glucose >or=170 mg/dl; n = 28) participated in the study. MAIN OUTCOME MEASURES: We assessed fasting and postprandial levels of glucose, insulin, lipids, high sensitivity C-reactive protein, plasminogen activator inhibitor-1, and adiponectin and endothelial function using reactive hyperemia peripheral arterial tonometry. RESULTS: Normal glucose tolerance and PCH subjects were matched for age, sex, body mass index, and ethnicity. Fasting glucose (102 +/- 3 vs. 93 +/- 2 mg/dl; P < 0.001) and glycosylated hemoglobin (5.7 vs. 5.4%; P = 0.01) were modestly higher in the PCH group, which was also more insulin resistant (homeostasis model assessment for insulin resistance, 7.0 +/- 1.3 vs. 4.1 +/- 0.6; P = 0.03). Fasting high sensitivity C-reactive protein was higher (2.6 +/- 0.5 vs. 1.3 +/- 0.2 mg/dl; P = 0.05), and adiponectin was lower (11.6 +/- 1.6 vs. 14.0 +/- 1.3 microg/ml; P = 0.03) in subjects with PCH. Peak and 6-h postprandial area under the curve glucose, insulin, and lipids were higher in PCH subjects, who also had higher fasting and postprandial levels of plasminogen activator inhibitor-1. Reactive hyperemia peripheral arterial tonometry declined postprandially only in PCH. CONCLUSIONS: Older adults with PCH experience significant fasting and postprandial metabolic dysregulation, which is accompanied by a proatherosclerotic and prothrombotic vascular profile.