Associations of cardiorespiratory fitness and muscle strength during pregnancy with metabolic health outcomes and inflammatory parameters at 1-year postpartum in women after gestational diabetes.

BACKGROUND: Women with gestational diabetes mellitus (GDM) have increased risk of insulin resistance, glucose intolerance, and low-grade systemic inflammation in the postpartum. Higher cardiorespiratory fitness (CRF) and muscular strength are associated with improved metabolic outcomes in the general population, but data in women with GDM are lacking. We investigated the longitudinal associations of CRF and muscular strength during pregnancy with glucose intolerance, insulin resistance and inflammation parameters at 1-year postpartum in women with GDM. METHODS: This is a secondary analysis of the MySweetHeart trial, which included 179 women with GDM. During pregnancy, CRF was assessed using the Chester Step test, and muscular strength was measured via handgrip strength (HS) and adjusted for pre-pregnancy body mass index (BMI). At one-year postpartum, participants underwent a 75 g oral glucose tolerance test, and we calculated HOMA-IR and MATSUDA index. We calculated glucose intolerance and assessed metabolic syndrome (MetS) and c-reactive protein (CRP) at 1-year postpartum. RESULTS: Higher CRF during pregnancy was associated with lower risk of glucose intolerance, MetS, and insulin resistance at one-year postpartum (all p ≤ 0.047). These associations were attenuated after adjusting for classical diabetes risk factors including family history of diabetes, age, ethnicity, and pre-pregnancy BMI. Higher HS during pregnancy was associated with lower CRP, HOMA-IR, higher MATSUDA index, and reduced MetS (BMI-based) at one-year postpartum, independent of classical diabetes risk factors (all p ≤ 0.035). CONCLUSION: In this longitudinal cohort of women with GDM, higher CRF and HS during pregnancy were protective of adverse metabolic health outcomes at 1-year postpartum. The relationship between HS and metabolic health was independent of classical diabetes risk factors.