Abstract P015: Associations Of Physical Activity And Lactation Duration With Cardiometabolic Risk Factors: The Cardia Study

Background: Physical activity (PA) and lactation individually benefit cardiometabolic health. Joint associations of PA and lactation with cardiometabolic risk factors have not been described. Methods: We averaged PA across all attended exams and summed total lactation duration in 1,068 Black and White parous women who attended the Year 30 Coronary Artery Risk Development in Young Adults (CARDIA) examination. Two categories were created for PA (-PA: below median; +PA: ≥median) and lactation duration (-L: <3 months, +L: ≥3months). Participants were assigned to one of four groups based on PA patterns and cumulative lactation duration: -PA/-L, -PA/+L, +PA/-L, +PA/+L (most favorable). Cardiometabolic risk factors measured at Y30 were combined and standardized into a composite cardiometabolic risk score. We used linear regression to evaluate associations of group assignments with individual cardiometabolic risk factors and risk score. Covariates included age, race, study center, parity, education, smoking, medication use, alcohol consumption, baseline body mass index (BMI), and baseline diet quality. Results: Median PA=256 exercise units (IQR: 168-379), and 581 (54%) of participants reported cumulative lactation duration ≥3 months. Of the 1,068 participants, 303 were in the -PA/-L category, 231 in -PA/+L, 184 in +PA/-L, and 350 in +PA/+L. Participants in the +PA/+L category were older, had more years of education, lower BMI, gained less weight during follow-up, and were less likely to be Black versus the -PA/-L category. Mean cardiometabolic risk scores improved across categories and were not significantly different between -PA/+L and +PA/-L: -PA/-L: 0.23±0.04, -PA/+L: 0.08±0.04, +PA/-L: -0.02±0.05, +PA/+L: -0.23±0.03 all p≤0.08. After adjustment, +PA/+L assignment was associated with a lower (better) cardiometabolic risk score (β= -0.15, 95%CI: -0.25, -0.04) with no interactive effect of race, p=0.22. Associations were nonsignificant after accounting for 30-year change in BMI. Conclusions: Attaining above average PA combined with ≥3 months of lactation was associated with the most favorable cardiometabolic risk score in Black and White women. Participants who achieved either one of these behaviors had lower risk scores versus those with neither behavior. Attaining these levels of PA and/or lactation may reduce cardiometabolic risk in parous women due to less weight gain over time.