ABNORMALITIES OF INTERMEDIARY METABOLISM FOLLOWING A GESTATIONAL DIABETIC PREGNANCY

OBJECTIVE The aim of this study was to compare intermediary metabolism in glucose tolerant women with previous gestational diabetes and control women without a history of gestational diabetes. SUBJECTS Fifteen women with previous gestational diabetes and 15 controls individually matched for race, age and body mass index were included. Only subjects with normal glucose tolerance were included in this study. METHODS Plasma glycerol, 3-OH butyrate, non-esterified fatty acids (NEFA), glucose and insulin were measured fasting and following a 75 g oral glucose load. RESULTS The women with previous gestational diabetes and their matched controls were of similar racial origin, age and body mass index. There was no difference between those with previous gestational diabetes and controls in fasting glycerol, 3-OH butyrate, NEFA, glucose or insulin concentrations. Following the oral glucose load, glycerol, 3-OH butyrate and NEFA concentrations fell in both groups. However, compared with controls at 120 minutes, those with previous gestational diabetes had significantly higher concentrations of glycerol (median 57, range 24-216 vs 27, range 8-89-mu-mol/l, P < 0.005) and 3-OH butyrate (9, range 1-18 vs 5, range 2-11-mu-mol/l, P < 0.01). NEFA concentrations were similar in the two groups. Despite similar glucose concentrations during the oral glucose tolerance test the insulin response during the first 60 minutes following oral glucose was significantly reduced in the subjects with previous gestational diabetes when compared with controls (insulin area, 0-60 minutes; 2172, range 788-4767 vs 2830, range 996-4784 pmol min/l, P < 0.05). CONCLUSIONS Women with a previous history of gestational diabetes, despite having normal glucose tolerance, have defective insulin release with resultant abnormalities of intermediary metabolism.