Elevation of plasma leptin levels during pregnancy in normal and diabetic women

The impact of pregnancy and food intake on plasma leptin levels was investigated in insulin-dependent diabetes mellitus (IDDM) patients and healthy normal-weight women. Fourteen women with IDDM and 11 women with no diabetes or family history of diabetes were served a 707-kcal lunch in gestational weeks 34 to 38. Six breast-feeding women from each group were examined a second time within 1 month after delivery. Leptin levels were not different in the two groups either during pregnancy or postpartum. In addition to a positive correlation to body mass index (BMI), leptin levels tended to correlate with gestational weight gain. The leptin concentration during pregnancy was higher than the postpartum level, which was within the range of previously reported levels in non-obese nonpregnant women. Ingestion of the test meal did not affect leptin levels and there were no relationships between leptin and insulin or glucose, for either basal or postprandial (60-minute) levels. Only the insulin dose taken by the diabetic women correlated to leptin level. During pregnancy, there is an augmented energy expenditure and maternal metabolism is altered to increase fat stores. The present observation that leptin levels were elevated in pregnant women suggests an additional role for leptin in the accumulation of body fat.