Carbohydrate metabolism in Down's syndrome.

Carbohydrate metabolism was studied in eight patients with Down's syndrome, aged 8 to 18 years. Diabetic glucose tolerance was observed in only one patient with obesity. This impaired glucose tolerance was improved with the weight reduction due to diet restriction. The flat glucose tolerance curves with low peak values were also observed in the other two patients. In the remaining five patients, normal glucose tolerance was obtained. Insulin response and free fatty acid levels during oral glucose load were not characteristic except for the diabetic patient with obesity. The sera of Down's syndrome showed normal binding capacity for insulin. These results suggest that obesity might partly participate in the impaired glucose tolerance in Down's syndrome.