Maternal Overweight vs. Polycystic Ovary Syndrome: Disentangling Their Impact on Insulin Action in Pregnancy-A Prospective Study.

BACKGROUND

To investigate insulin sensitivity and glucose metabolism in pregnant lean and overweight polycystic ovary syndrome (PCOS) patients vs. lean and overweight controls without PCOS.

METHODS

Prospective cohort study on 67 pregnant women (31 with PCOS and 36 controls, subdivided into overweight or obese and normal weight). All women underwent a 2h-OGTT including glucose, insulin, and C-peptide in early- and mid-gestation and were followed-up until delivery.

RESULTS

Insulin sensitivity and glucometabolic parameters were comparable between PCOS patients and controls, whereas marked differences were observed between overweight/obese and lean mothers. Impaired whole-body insulin sensitivity at early pregnancy is mainly a consequence of higher BMI (body mass index; 0.001) compared to PCOS ( 0.216), whereby no interaction between overweight/obesity and PCOS was observed ( 0.194). Moreover, overweight was significantly associated with gestational diabetes ( 0.0003), whereas there were no differences between women with and without PCOS ( 0.51). Birth weight was inversely related to whole-body insulin sensitivity (rho = -0.33, 0.014) and positively associated with higher pregestational BMI (rho = 0.33, 0.012), whereas there was no association with PCOS.

CONCLUSIONS

Impaired insulin action was mainly a consequence of overweight rather than PCOS. Our data suggest that overweight is more relevant than PCOS for the effects on insulin sensitivity and impaired glucose metabolism.