Protein and nitrogen metabolism in gestational diabetes

Metabolic perturbations associated with gestational diabetes mellitus (GDM) have been shown to result in significant clinical morbidity, both for the mother and the neonate. Although a number of studies have documented the changes in glucose metabolism in GDM, the data on nitrogen and protein metabolism remain scant. Recent data in GDM show that 1) the rate of irreversible nitrogen loss as measured by the rate of urea synthesis in GDM is similar to that in normal pregnancy and is less than that in nonpregnant women; and 2) possibly related to the magnitude of metabolic decompensation as assessed by the nature of therapeutic intervention (diet or diet plus insulin), the rate of protein turnover measured by leucine kinetics is increased in insulin-treated GDM. Whether the decompensation in protein turnover contributes to the persistent fetal macrosomia, even in rigorously managed GDM, remains speculative.