The relationship between moderate-to-vigorous intensity physical activity and insulin resistance, insulin-like growth factor (IGF-1)-system 1, leptin and weight change in healthy women during pregnancy and after delivery

ContextChildbearing is considered to be a significant risk factor for developing overweight and obesity. Physical activity might influence weight change via hormonal changes. ObjectiveTo test the hypothesis that higher levels of moderate-to-vigorous intensity physical activity (MVPA) are positively associated with maternal insulin sensitivity and reduce IGF-1, IGFBP-3, leptin levels, bodyweight gain/retention and birth weight. MethodsIn healthy nulliparous women, weight measurements were carried out and blood was collected during pregnancy in the 15th, 25th and 35th week, and after delivery at 6, 26 and 52weeks. At 15 and 35weeks of pregnancy and 26weeks postpartum, MVPA was measured using accelerometers. In linear regression models, the relationship between MVPA below or above the median with metabolic and weight outcomes was assessed, adjusted for maternal BMI, age and smoking. ResultsModerate-to-vigorous intensity physical activity (MVPA) decreased significantly during pregnancy, but was very low already in early pregnancy. Insulin resistance and leptin levels increased during pregnancy and decreased significantly after delivery (all P<005). After adjustment, insulin, IGFBP-3 and BMI were significantly lower at 15weeks of pregnancy in women with MVPA above the median compared to those with MVPA below the median. After 15weeks of pregnancy, no significant associations were observed between hormonal levels and MVPA. MVPA was neither related to weight retention, nor to birth weight. ConclusionExcept in early pregnancy, MPVA was not related to metabolic outcomes. In addition, MVPA during pregnancy was not related to weight retention or birth weight.