No abstract

OBJECTIVE To evaluate 25-year physical activity (PA) trajectories from young to middle-age and assess associations with the prevalence of coronary arterial calcification (CAC). PATIENTS and METHODS 3,175 participants in CARDIA study self-reported PA by questionnaire at 8 follow up exams over 25 years (March 1985- June 1986 to June 2010-May 2011). The presence of CAC (CAC>0) at year 25 was measured using computed tomography. Group-based trajectory modeling was used to identify PA trajectories with increasing age. RESULTS We identified 3 distinct PA trajectories: Trajectory 1: Below PA guidelines (n= 1813; 57.1%); Trajectory 2: Meeting PA guidelines (n= 1094; 34.5%); and, Trajectory 3: Three times PA guidelines (n= 268; 8.4%). Trajectory 3 participants had higher adjusted odds of CAC>0 (AOR 1.27; 95% CI: 0.95, 1.70) versus those in Trajectory 1. Stratification by race showed that whites engaged in PA three times the guidelines had higher odds of developing CAC>0 with OR 1.80 (95% CI: 1.21, 2.67). Further stratification by gender showed higher odds for white males (OR 1.86; 95% CI: 1.16, 2.98), while similar, but non- significant trends were noted for white females (OR 1.71; 95% CI: 0.79, 3.71). However, no such higher odds of CAC>0 for Trajectory 3 were observed for black participants. CONCLUSIONS White individuals who participated in three times the recommended PA guidelines, over 25-years, had higher odds of developing coronary subclinical atherosclerosis by middle-age. These findings warrant further exploration, especially by race, into possible biological mechanisms for CAC risk at very high levels of PA.

No abstract

Background Chronic stress and/or lifetime traumatic stress can create a self-reinforcing cycle of unhealthy behaviors, such as overeating and sedentary behavior, that can lead to further increases in stress. This study examined the relationship between stress and sedentary behavior in a sample of Hispanic/Latino adults (N = 4244) from the Hispanic Community Health Study/Study of Latinos Sociocultural Ancillary Study. Methods Stress was measured as the number of ongoing difficulties lasting 6 months or more and as lifetime exposure to traumatic events. Sedentary behavior was measured by self-report and with accelerometer. Multivariable regression models examined associations of stress measures with time spent in sedentary behaviors adjusting by potential confounders. Results Those who reported more than one chronic stressor spent, on average, 8 to 10 additional minutes per day in objectively measured sedentary activities (P < .05), whereas those with more than one lifetime traumatic stressor spent (after we adjusted for confounders) 10 to 14 additional minutes in sedentary activities (P < .01) compared with those who did not report any stressors. Statistical interactions between the 2 stress measures and age or sex were not significant. Conclusion Interventions aimed at reducing sedentary behaviors might consider incorporating stress reduction into their approaches.

Purpose We investigated associations of acculturation with various types of activity (moderate-vigorous leisure-time physical activity (LTPA), moderate-vigorous work- and transportation-related physical activity and sedentary activity), and whether these activities mediated the acculturation-obesity association among Mexican-Americans. Design Cross-sectional. Setting National Health and Nutrition Examination Surveys 2007–2010. Subjects Mexican-American NHANES participants aged ≥ 20 years (n=1,902). Measures Demographic characteristics, physical activity, sedentary behavior, acculturation and body mass index. Analysis Multinomial logistic regression was used to estimate associations of acculturation with categories of self-reported activity. Path analysis was used to test whether the activity measures mediated acculturation-obesity associations. Results In adjusted models, compared to US-born Mexican-Americans, foreign-born Mexican-Americans living in the US <10 years were significantly less likely to be in the highest LTPA and sedentary activity categories, and more likely to be in the highest total and transportation activity categories. Foreign-born Mexican-Americans living in the US ≥10 years were significantly less likely to engage in high sedentary activity but more likely to engage in high transportation activity. Sedentary behavior was the strongest mediator of the acculturation-obesity association, accounting for 40.7% and 57.1% of the total effect of acculturation on obesity among foreign-born Mexican-Americans living in the US < 10 years and ≥10 years, respectively, compared to US-born Mexican-Americans. Conclusion Reducing sedentary behavior may lower the negative impact of acculturation on obesity.