Insulin sensitivity and resistin levels in gestational diabetes mellitus and after parturition

Context: Resistin is expressed and secreted by the placenta during pregnancy. Increased serum resistin levels have been found in the second half of normal pregnancy, but its role in the pathogenesis of the insulin resistance of pregnancy is undetermined. Objective: The objective of the study was to assess the relationship between circulating resistin levels and insulin sensitivity in gestational diabetes mellitus (GDM). Design and setting: A case (n=23)-control (n=35) study was performed at the obstetrics and endocrinology clinic of a university hospital. Patients: In total, 58 Caucasian women with a singleton pregnancy who had been referred for a 100 goral glucose tolerance test were enrolled between the weeks 26 and 30, and 22 women with GDM were also evaluated after pregnancy. Main outcome measures: Serum resistin and insulin sensitivity in GDM during and after pregnancy. The relationship of resistin to metabolic abnormalities was evaluated. Results: Resistin levels were lower in GDM women than in pregnant women with normal glucose tolerance (NGT)(4.32 +/- 1.56vs9.30 +/- 1.32 ng/ml, P < 0.001), and experienced a further decrease after parturition (4.24 +/- 1.56vs3.11 +/- 1.63 ng/ml, P=0.003). The association between low serum resistin levels and the diagnosis of GDM was independent of the degree of insulin sensitivity. Conclusion: Lower resistin levels were observed in GDM than in NGT women and decreased after parturition, suggesting a role for resistin in the development of this disease. But we have failed to find an independent relationship between resistin levels and insulin sensitivity during pregnancy.