Abstract
Background
Variability in glucose levels during pregnancy can adversely affect foetal development. A strong positive relationship between physical activity (PA) and glucose variability has been observed in pregnancy, which could inform strategies to improve gestational glycaemia. However, no study has previously measured objective PA and glucose variability disaggregated by pregnancy trimester, despite trimester-specific differences in glucose control being reported. Additionally, whether a relationship exists between PA and glucose control postpartum is unknown. The aim of this study was to assess the relationship between PA and glucose control across the perinatal period, disaggregated by trimester and postpartum, using objective continuous assessment methods.
Methods
Forty-nine healthy, non-diabetic pregnant females, with no history of cardiovascular or respiratory disease, aged 28-46 years were recruited. Accelerometery was used to measure PA, alongside continuous glucose monitoring to assess glucose variability over a week, at trimesters 2 and 3 of pregnancy, and within 6 weeks postpartum. Variability of PA & blood glucose across the perinatal period was assessed using general linear models and the relationship between PA and glucose variability were assessed using hierarchal regressions.
Results
No significant change in glucose variability (coefficient of variation) was reported across the perinatal period (21.12 ± 4.32%, 21.42 ± 4.39%, 18.97 ± 4.11% in trimesters 2, 3, and postpartum respectively). Light-intensity PA increased across the perinatal period (152 ± 48, 161 ± 38, 201 ± 93 mins/day in trimesters 2, 3, and postpartum, respectively), with no change in moderate-to-vigorous or total physical activity levels, though PA levels were low at all timepoints compared to previous literature. No relationship between glucose variability and physical activity was identified across the perinatal period.
Conclusions
This observational study provides preliminary evidence that contrary to previous findings, there may be no relationship between PA and glucose variability in healthy pregnancies disaggregated by trimester, though higher levels of PA and/or structured exercise may be required to influence metabolic health.
Trial Registration: Integrated Research Application System (IRAS) number 263600.