Abstract P263: Racial Differences in the Association Between Physical Activity Levels During Early Adulthood and Visceral Adiposity at Middle Age: The CARDIA Study

Abstract

Background: Excess visceral adiposity tissue (VAT) is associated with elevated free fatty acids that contribute to dyslipidemia, beta cell dysfunction, and insulin resistance. Greater physical activity (PA) is associated with lower VAT cross-sectionally, but whether PA during young adulthood is associated with VAT at middle age independent of general obesity is unclear. Objective: To quantify by sex and race the associations between PA levels in young adulthood with visceral adiposity measured 25 years later. Methods: The Coronary Artery Risk Development in Young Adults (CARDIA) study is a population-based, prospective, observational study of black and white men and women. Habitual PA was determined as the average of baseline and year 7 levels (18–37 yrs) of the CARDIA Physical Activity Score. VAT (cm3) was assessed by computed tomography at the year 25 exam (43–55 yrs, n=1822). Results: Early adulthood PA levels were 15.2% lower in blacks compared to whites (p<0.001) and 30.0% lower in women compared to men (p<0.001); the lowest PA levels were observed in black women. Compared with the highest levels of PA, participants with moderate or lower PA during young adulthood exhibited higher VAT at middle age in linear regression models adjusted for covariates including year 25 BMI (Table 1). When stratified by race and sex, white men and women with higher PA levels exhibited lower VAT at middle age compared to white adults with moderate or lower PA; an association not observed in black men or women. Conclusions: White men and women engaging in higher PA levels at earlier ages may demonstrate lower visceral adiposity later in life, yet these findings suggest that PA may not be a solely effective approach at reducing/preventing cardiometabolic risk from excess visceral adiposity in black adults. Racial variations in the influence of young adulthood PA on visceral adiposity at middle age may reflect differential influences of PA, PA intensity, or other unmeasured risk factors (e.g., psychosocial stress) on adiposity distribution.