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. Further, 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 utilizing 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 towards non-oxidized 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 elicited an increase in glucose oxidation in AA, but not in C. Together, these data suggest that metabolic differences between AA and C races may exist at birth.