African American Females Are Less Metabolically Flexible Compared with Caucasian American Females following a Single High-Fat Meal: A Pilot Study

Chronic GLP1 therapy reduces postprandial IL6 in obese humans with prediabetes

Single-dose glucagon-like peptide 1 (GLP1) therapy increases postprandial plasma IL6 levels in prediabetic, obese humans. GLP1-IL6 interactions underly multiple antidiabetic effects, but these may differ after acute versus chronic therapy. This study examines postprandial effects of GLP1 after chronic therapy. Seven humans (six Black) with prediabetes and obesity completed 6 weeks of exenatide extended release therapy. Then subjects returned for pre- and post-meal measurements of plasma IL6, GLP1, glucagon, and related inflammatory markers. Weight, which was measured before and after therapy, did not change. Plasma IL6 decreased from baseline to postmeal state ( = 0.016), with decreases in free fatty acids (P < 0.001) and increases in insulin (P = 0.002), glucose (P < 0.0001), triglycerides (P = 0.0178), and glucagon (P = 0.018). Baseline GLP1 levels matched 6 weeks of therapy. The fall in postprandial plasma IL6, which contrasts with the increase after acute therapy, highlights the need for more investigation regarding the mechanisms of acute versus chronic GLP1-IL6 signaling.

Differences in substrate metabolism between African American and Caucasian infants: evidence from mesenchymal stem cells

Type 2 diabetes is more prevalent in African American (AA) than Caucasian (C) adults. Furthermore, differential substrate utilization has been observed between AA and C adults, but data regarding metabolic differences between races at birth remains scarce. The purpose of the present study was to determine if there are racial differences in substrate metabolism evident at birth using a mesenchymal stem cells (MSCs) collected from offspring umbilical cords. Using radio-labeled tracers, MSCs from offspring of AA and C mothers were tested for glucose and fatty acid metabolism in the undifferentiated state and while undergoing myogenesis in vitro. Undifferentiated MSCs from AA exhibited greater partitioning of glucose toward nonoxidized glucose metabolites. In the myogenic state, AA displayed higher glucose oxidation, but similar fatty acid oxidation rates. In the presence of both glucose and palmitate, but not palmitate only, AA exhibit a higher rate of incomplete fatty acid oxidation evident by a greater production of acid-soluble metabolites. Myogenic differentiation of MSCs elicits an increase in glucose oxidation in AA, but not in C. Together, these data suggest that metabolic differences between AA and C races exist at birth.NEW & NOTEWORTHY African Americans, when compared with Caucasians, display greater insulin resistance in skeletal muscle. Differences in substrate utilization have been proposed as a factor for this health disparity; however, it remains unknown how early these differences manifest. Using infant umbilical cord-derived mesenchymal stem cells, we tested for in vitro glucose and fatty acid oxidation differences. Myogenically differentiated MSCs from African American offspring display higher rates of glucose oxidation and incomplete fatty acid oxidation.