Impaired Mitochondrial Activity in the Insulin-Resistant Offspring of Patients with Type 2 Diabetes

Insulin resistance appears to be the best predictor of the development of diabetes in the children of patients with type 2 diabetes, but the mechanism responsible is unknown.

We performed hyperinsulinemic-euglycemic clamp studies in combination with infusions of [6,6-(2)H(2)]glucose in healthy, young, lean, insulin-resistant offspring of patients with type 2 diabetes and insulin-sensitive control subjects matched for age, height, weight, and physical activity to assess the sensitivity of liver and muscle to insulin. Proton ((1)H) magnetic resonance spectroscopy studies were performed to measure intramyocellular lipid and intrahepatic triglyceride content. Rates of whole-body and subcutaneous fat lipolysis were assessed by measuring the rates of [(2)H(5)]glycerol turnover in combination with microdialysis measurements of glycerol release from subcutaneous fat. We performed (31)P magnetic resonance spectroscopy studies to assess the rates of mitochondrial oxidative-phosphorylation activity in muscle.