ABSTRACT
CONTEXT: Semaglutide, a once-weekly glucagon-like peptide-1 analog approved for use in patients with type 2 diabetes (T2D), demonstrated superior body weight (BW) reductions and decreased insulin resistance (IR) vs comparators across the Semaglutide Unabated Sustainability in Treatment of Type 2 Diabetes (SUSTAIN) 1-3 clinical trials. OBJECTIVE: To investigate the relationship between IR and BW across the SUSTAIN 1-3 trials. DESIGN: Post hoc analysis of the SUSTAIN 1-3 trials. SETTING: Three hundred and eleven sites in 30 countries. PATIENTS OR OTHER PARTICIPANTS: 2432 subjects with T2D. INTERVENTIONS: Semaglutide 0.5 or 1.0 mg, placebo or active comparator (sitagliptin 100 mg, exenatide extended release 2.0 mg). MAIN OUTCOME MEASURE: To assess the extent of the effect on IR that is mediated (indirect effect) and not mediated (direct effect) by the effect on BW. RESULTS: Across SUSTAIN 1-3, mean BW was significantly reduced with semaglutide 0.5 mg (3.7 kg to 4.3 kg; P < 0.0001) and semaglutide 1.0 mg (4.5 kg to 6.1 kg; P < 0.0001) vs comparators (1.0 kg to 1.9 kg). There were greater reductions in IR with semaglutide 0.5 mg (27% to 36%) and semaglutide 1.0 mg (32% to 46%) vs comparators (17% to 28%). Greater reductions in BW were generally associated with greater decreases in IR. The effect on IR was primarily mediated by weight loss (70% to 80% and 34% to 94%, for semaglutide 0.5 mg and 1.0 mg, respectively, vs comparator). CONCLUSIONS: Semaglutide consistently reduced BW and IR in subjects with T2D in SUSTAIN 1-3. In this analysis, IR improvement was positively associated with, and primarily mediated by, the effect of semaglutide on BW.
ABSTRACT
CONTEXT: Human exposure to polychlorinated biphenyls (PCBs) has been associated to type 2 diabetes in adults. OBJECTIVE: We aimed to determine whether concurrent plasma PCB concentration was associated with markers of glucose metabolism in healthy children. SETTING AND DESIGN: Cross-sectional study of 771 healthy Danish third grade school children ages 8-10 years in the municipality of Odense were recruited in 1997 through a two-stage cluster sampling from 25 schools stratified according to location and socioeconomic character; 509 (9.7 ± 0.8 y, 53% girls) had adequate amounts available for PCB analyses. OUTCOME MEASURES: Fasting serum glucose and insulin were measured and a homeostasis assessment model of insulin resistance (HOMA-IR) and ß-cell function (HOMA-B) calculated. Plasma PCB congeners and other persistent compounds were measured and ΣPCB calculated. RESULTS: PCBs were present in plasma at low concentrations, median, 0.19 µg/g lipid (interquartile range, 0.12-0.31). After adjustment for putative confounding factors, the second, third, fourth, and fifth quintiles of total PCB were significantly inversely associated with serum insulin (-14.6%, -21.7%, -18.9%, -23.1%, P trend < .01), compared with the first quintile, but not with serum glucose (P = .45). HOMA-IR and HOMA-B were affected in the same direction due to the declining insulin levels with increasing PCB exposure. Similar results were found for individual PCB congeners, for ßHCB (hexachlorobenzen) and pp-DDE (dichlorodiphenyldichloroethylene). CONCLUSIONS: A strong inverse association between serum insulin and PCB exposure was found while fasting glucose remained within the expected narrow range. Our findings suggest that PCB may not exert effect through decreased peripheral insulin sensitivity, as seen in obese and low-fit children, but rather through a toxicity to ß-cells. It remains to be demonstrated whether lower HOMA-B is caused by destruction of ß-cell-reducing peripheral insulin resistance and thereby increase fasting glucose as previously found.
