INSULIN RESISTANCE AND EXCESS WEIGHT IN ADOLESCENT INSULIN-DEPENDENT DIABETIC GIRLS

Insulin dependent diabetic adolescent girls show a tendency towards ex cess weight. The relationship between insulin resistance and body mass index (BMI) was investigated in 23 Type 1 adolescents aged 13-20 yr. These patients body mass indexes spanned from 19.8 to 30.5. Excess wei ght was evaluated using Z-scores, corrected for age with reference to french standards. 9 patients with a Z-score greater than 2 were consid ered as obese. Insulin sensibity was measured using the hyperinsulinae mic euglycaemic clamp (insulin infusion rate, 1 mU kg-1 min-1). The me an glucose infusion rate during the clamp was low in the diabetic girl s (2.29 +/- 1.35 mg kg-1 min-1), confirming the existence of insulin r esist ce. However, the degree of insulin resistance was not correlated with the excess in weight (glucose infusion rate, 2.23 +/- 1.24 vs 2. 33 +/- 1.46 mg kg-1 min-1 in the obese and the non-obese patients, res pectively). None of the factors which influe on insulin sensivity coul d explain this lack of correlation, the obese patients showing greater daily insulin doses (1.36 +/- 0.22 vs 1.22 +/- 0.25 unit kg-1 day-1) and worse metabolic control (Hba1C, 10.9 +/- 1.4 vs 10.2 +/- 2.0%). In sulin resistance was significantly correlated with free fatty acid lev els during the clamp.