Behavior reallocations within 24‐h movement profiles and change in cardiometabolic biomarkers during pregnancy

Abstract Objective The goal of this study was to investigate associations of reallocations within 24‐h movement profiles and changes in cardiometabolic biomarkers from early to late pregnancy. Methods In 137 individuals with prepregnancy overweight/obesity, waking movement was measured using wrist‐worn accelerometers, sleep was self‐reported, and biomarkers were measured in fasting serum samples at 12 and 32 weeks’ gestation. We used compositional isotemporal substitution models. Results On average, biomarkers increased 21%–83% across pregnancy. For those with guideline‐recommended moderate/vigorous‐intensity physical activity (MVPA) in early pregnancy, reallocating 30 min from MVPA to sleep, sedentary behavior, or light‐intensity physical activity (LPA) was associated with a 0.6 mmol/L greater increase in total cholesterol (95% CI: −0.1 to 1.2) and a 0.7 mmol/L greater increase in low‐density lipoprotein (LDL) cholesterol (95% CI: 0.1 to 1.3) from early to late pregnancy. For those with low MVPA in early pregnancy, reallocating 30 min from sleep, sedentary behavior, or LPA to MVPA was associated with a 0.6 mmol/L lower increase in total cholesterol (95% CI: −1.3 to 0.1) and a 0.8 mmol/L lower increase in LDL cholesterol (95% CI: −1.4 to −0.1) from early to late pregnancy. There were no associations with change in glucose, insulin, homeostatic model assessment for insulin resistance, very low‐density lipoprotein, or high‐density lipoprotein cholesterol, triglycerides, or free fatty acids. Conclusions Maintaining or achieving a 24‐h movement profile with guideline‐recommended amounts of MVPA may be beneficial for reducing pregnancy‐induced increases in total and LDL cholesterol.