Objectively Measured Physical Activity During The First Trimester And Glucose Tolerance At 24-28 Weeks Gestation

Abstract

Physical activity (PA) during pregnancy may improve glucose tolerance and reduce the risks of adverse outcomes associated with pregnancy hyperglycemia (e.g., pregnancy and delivery complications, delivering a large infant, and developing diabetes later in life), yet the evidence to date has primarily relied on self-reported PA via questionnaire. PURPOSE: To examine whether objectively measured PA during the first trimester of pregnancy is associated with glucose tolerance at 24-28 weeks’ gestation. METHODS: Study participants (n=261) were a subsample of the GestationaL Weight Gain and Optimal Wellness (GLOW) trial conducted at Kaiser Permanente Northern California in 2014-2016 to test whether a lifestyle intervention prevents excess gestational weight gain in women with overweight/obesity, as compared to usual medical care. Participants wore an ActiGraph wGT3X-BT for 7 days on the non-dominant wrist during the first trimester. Valid measurements were defined as having ≥ 600 minutes of wear time [by the algorithm of Choi et al. (MSSE, 2012)] on 4 days, including 1 weekend day. Wrist-specific two-regression algorithms [Hibbing et al. (MSSE, 2018)] were used to estimate daily minutes of moderate to vigorous intensity PA (MVPA), light PA (LPA), and sedentary behavior (SB). Minutes per day of MVPA, LPA, and SB were then combined into weighted (i.e., weekend day vs. weekday) averages. Plasma glucose values from a random, 50-g 1-hour glucose challenge test (GCT) performed at 24-28 weeks’ gestation were obtained from the Kaiser Permanente Northern California electronic health records. Associations of MVPA, LPA and SB (i.e., log transformed) with glucose were estimated by linear regression and adjusted for age, race-ethnicity, BMI category, and GLOW trial randomization (i.e., intervention vs. usual care). RESULTS: The cohort had a median 38 (IQR= 37) minutes per day of MVPA, 248 (81) minutes per day of LPA, and 389 (97) minutes per day of SB. The median plasma glucose value on the GCT was 112 mg/dl (35). None of the PA variables were statistically significantly associated with plasma glucose (p > .05 for MVPA, LPA, and SB). CONCLUSION: Objectively measured PA, assessed over 7 days during the first trimester of pregnancy, does not appear to impact glucose tolerance at 24-28 weeks gestation in women with overweight/obesity.