Hyperinsulinemia in macrosomic infants of nondiabetic mothers

Abstract

Objective: We tested the hypothesis that macrosomic infants of nondiabetic mothers are more likely to have hyperinsulinemia and increased subcutaneous fat.

Research design and methods: Plasma insulin concentrations were measured in cord blood from 50 macrosomic infants and 32 normal-sized (control), term infants. All mothers had had a normal 50-g 1-h GCT. Skin-fold measurements of the triceps and subscapular area were done on 44 macrosomic infants with a Halpern caliper.

Results: No difference was observed in GCT between mothers of macrosomic (5.8 +/- 1.0 mM) and normal (5.7 mM) infants. The insulin level in macrosomic infants (18.75 +/- 19.08 microU/ml) was significantly higher than in control infants (8.67 +/- 6.64 microU/ml). Macrosomia was a predictor of hyperinsulinemia and vice versa (R2 = 0.26). Maternal height, prepregnancy weight, and weight gain were predictors for macrosomia (R2 = 0.26). No differences were noted in anthropometric measurements between hyperinsulinemic and normoinsulinemic infants.

Conclusions: A subset of macrosomic infants have hyperinsulinemia. Maternal anthropometric factors as well as hyperinsulinemia are correlated with macrosomia. The macrosomia may be causally related to the high insulin levels.