Glucose transport and oxidation in adipose tissue of patients with myotonic dystrophy

Abstract

The effect of insulin on the transport of 2-deoxyglucose and the oxidation of glucose in chopped adipose tissue was investigated in 14 myotonic dystrophy (MyD) patients and 28 age and size-matched control subjects. The transport of 0.55 mM 2-deoxyglucose was measured over 3 min at 37°C both with and without 32 ng/ml of insulin. Oxidation was determined at 37°C for 90 min by the measurement of 14CO 2 released from a system containing 0.55 mM glucose with and without 50 ng/ml of insulin. Basal 2-deoxyglucose transport was not reduced in MyD subjects but insulinstimulated 2-deoxyglucose transport in MyD was significantly less at 0.512 ± 0.220 nmole compared to control subjects with 0.906 ± 0.160 nmole 100 mg tissue 3 min ( P < 0.02). Both the basal and insulin-stimulated glucose oxidation were significantly less in the MyD group. Insulin-stimulated oxidation was 2.92 ± 0.21 nmole in the control subjects compared to 2.20 ± 0.27 nmole 100 mg tissue 90 min in the MyD cases ( P < 0.02). Similar findings were obtained when calculations were based on nmoles of 2-deoxyglucose transport and glucose oxidation 100 mg lipid. The findings indicate that both glucose transport and oxidation are impaired in MyD.