Offspring sex modifies the association between early-pregnancy adiposity and 2-year-old total physical activity – The Glowing Study

Authors: DIAZ, EVA - University Arkansas For Medical Sciences (UAMS); WILLIAMS, DAVID - University Arkansas For Medical Sciences (UAMS); HOWIE, ERIN - University Of Arkansas; BORSHEIM, ELISABET - University Arkansas For Medical Sciences (UAMS); ANDRES, ALINE - University Arkansas For Medical Sciences (UAMS)

Submitted to: International Journal of Behavioral Nutrition and Physical Activity
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/6/2023
Publication Date: 1/20/2024
Citation: Diaz, E., Williams, D.K., Howie, E.K., Borsheim, E., Andres, A. 2024. Offspring sex modifies the association between early-pregnancy adiposity and 2-year-old total physical activity – The Glowing Study. International Journal of Behavioral Nutrition and Physical Activity. 48:542-549. https://doi.org/10.1038/s41366-023-01446-7.
DOI: https://doi.org/10.1038/s41366-023-01446-7

Interpretive Summary: Maternal obesity during pregnancy increases the risk of obesity and non-communicable diseases in the offspring across the lifespan. Animal models indicate that offspring born to mothers with obesity are less physically active. However, this has not been shown in humans due to the necessity of complex studies over long periods of time. The purpose of this study was to evaluate the association between maternal adiposity (fat content) measured early in pregnancy with 2-year-old offspring physical activity. Women were enrolled in the first trimester of pregnancy and seen on regular basis at the Arkansas Children's Nutrition Center. At age two years, children wore an accelerometer (fitness tracker) to measure their physical activity levels. Analyses considered maternal socioeconomic status (education), weight gain during pregnancy, maternal race, maternal physical activity early in pregnancy, birth weight, parenting styles, and toddler's weight status. Results from this study showed, that physical activity levels of 2 year old children decrease with increasing maternal fat. When mother's adiposity (fat content) was < 7 kg/m2 physical activity levels were comparable between boys and girls. However, when the fat content of mom exceeded 7 kg/m2 girls became less active compared to boys. In addition, offspring born to women without college degree were also less active compared to children born to women with college degree. For boys, maternal physical activity early in pregnancy was the variable that was more strongly associated with physical activity levels at the age of 2 years. Our results support the notion that maternal obesity affects offspring's attitudes and behaviors towards physical activity in a sex dependent manner.

Technical Abstract: Background: Rodent models suggest that in utero exposure to under and overnutrition programs offspring physical activity (PA) behaviors. Such nexus has not been established in humans. The purpose of this observational study was to evaluate the association of early pregnancy maternal adiposity with total offspring PA at age 2 years (2-yo-PA) taking into consideration prenatal and postnatal factors. Methods: Women (n=153) were enrolled early in pregnancy (<10 weeks). At enrollment, maternal adiposity [air displacement plethysmography, fat mass index (FMI, kg/m2)] and PA (accelerometers, activity counts) were measured, and age, race, and education self-reported. Gestational weight gain was measured at the research facility. Offspring birthweight and sex were self-reported. At age 2 years, parental feeding practices (child feeding questionnaire) were assessed, whereas anthropometrics (length and weight) and physical activity (accelerometers) were objectively measured. Offspring body mass index z-scores were calculated. Generalized linear regression analysis modeled the association of maternal FMI and 2-yo-PA [average activity counts (AC)4/day]. Results: There was an interaction between maternal FMI and offspring sex in association with 2-yo-PA (ß = -1.03, p = 0.030). Specifically, 2-yo-PA was lower in girls compared to boys only when maternal FMI was =7 kg/m2. Maternal PA early in pregnancy directly and positively associated with 2-yo-PA (ß = 0.21, p = 0.005). In addition, 2-yo-PA tended to be higher in children born to women with college education compared to children born to women without college education (ß = 3.46, p = 0.059). Conclusions: Sexual dimorphism was observed in the associations of early maternal adiposity with 2-yo-PA, with girls being less active compared to boys only when maternal FMI was =7 kg/m2.