POSTPRANDIAL CHANGES IN CYTOSOLIC FREE CALCIUM AND GLUCOSE-UPTAKE IN ADIPOCYTES IN OBESITY AND NON-INSULIN-DEPENDENT DIABETES-MELLITUS

We evaluated the possible relationship between [Ca2+]i and glucose uptake in the postabsorptive state and postprandially in adipocytes obtained from normal and obese subjects, as well as from patients with non-insulin-dependent diabetes mellitus (NIDDM). Adipocytes isolated from overnight-fasted obese and NIDDM patients revealed high levels of [Ca2+]i (p < 0.05 vs. control) in association with a decreased insulin-stimulated glucose uptake (p < 0.05 vs. controls). In obese and NIDDM patients treated with oral hypoglycemic agents, the overnight fasting levels of [Ca2+]i, were increased postprandially (p < 0.05), concomitantly with a further decrease in insulin-stimulated 2-deoxyglucose uptake. Although the precise nature of the relationship between [Ca2+]i in specific insulin target tissues and diminished insulin action remains unknown, it is clear that high levels of [Ca2+]i may contribute to the development of insulin resistance. © 1990 S. Karger AG, Basel.