IMPAIRED INSULIN-STIMULATED NONOXIDATIVE GLUCOSE-METABOLISM IN GLUCOSE-TOLERANT WOMEN WITH PREVIOUS GESTATIONAL DIABETES

OBJECTIVE: Our purpose was to investigate insulin sensitivity and insu lin secretion in women with previous gestational diabetes, STUDY DESIG N: Twelve women with previous gestational diabetes and 11 controls wer e examined by oral and intravenous glucose tolerance tests and a hyper insulinemic euglycemic clamp including indirect calorimetry. All women were lean and had normal oral glucose tolerance test results. Activit ies of glycogen synthase, phosphofructokinase, and hexokinase were mea sured in vastus lateralis muscle biopsy specimens obtained in the basa l state and after insulin stimulation. RESULTS: Women with previous ge stational diabetes had a decreased glucose disposal rate (rho < 0.01) because of a reduced insulin-stimulated nonoxidative glucose metabolis m (6.63 +/- 0.47 vs 9.04 +/- 0.57 mg/kg fat-free mass per minute, rho < 0.01). The muscle activities of glycogen synthase, phosphofructokina se, and hexokinase were similar in the two groups. The first-phase ins ulin response to the intravenous glucose tolerance test was, in absolu te terms, comparable in the two groups. However, when the decreased in sulin sensitivity was taken into account, women with previous gestatio nal diabetes had a relative insulin secretion deficiency. CONCLUSION: Women with previous gestational diabetes have a decreased insulin sens itivity and a relative impairment of insulin secretion.