Greater Leisure Time Physical Activity Is Associated with Lower Allostatic Load in White, Black, and Mexican American Midlife Women: Findings from the National Health and Nutrition Examination Survey, 1999 through 2004.

BACKGROUND: Allostatic load is a useful construct to understand how social and environmental conditions get under the skin to affect health. To date, few studies have examined health-enhancing lifestyle behaviors and their potential benefits in reducing allostatic load. The purpose of this study was to investigate the contributions of leisure time physical activity on level of allostatic load among White, Black, and Mexican American midlife women. METHODS: Data were from the National Health and Nutrition Examination Survey, 1999 through 2004 (n = 1,680, women ages 40-59). All analyses were weighted. Negative binomial regression was used to model a summative count measure of allostatic load (M = 2.30). Models were also computed to estimate adjusted predicted allostatic load for given levels of physical activity, and by race/ethnicity for each age category (40-44, 45-49, 50-54, 55-59), controlling for other demographics and medication use. FINDINGS: Higher levels of physical activity were associated significantly with lower levels of allostatic load, independent of demographics. Compared with White women ages 40 to 44, all other racial/ethnic-by-age groups had significantly higher allostatic load. Higher socioeconomic status was associated with a lower allostatic load. Adjusted prediction models demonstrated associations between greater levels of physical activity and lower allostatic load for all ages and racial/ethnic groups. CONCLUSIONS: Our findings suggest physical activity may ameliorate some of the effects of cumulative physiological dysregulation and subsequent disease burden in midlife women. Programs and policies that encourage and promote healthy aging and provide opportunities for a diversity of women to engage in health-enhancing lifestyle practices such as physical activity are recommended.

Racial and ethnic patterns of allostatic load among adult women in the United States: findings from the National Health and Nutrition Examination Survey 1999-2004.

OBJECTIVE: This study provides a descriptive sociodemographic profile of allostatic load (AL) among adult women of all age groups, focusing on how age patterns of AL vary across racial/ethnic groups. Allostatic load, an index of cumulative physiological dysregulation, captures how the cumulative impact of physiological stress responses from person-environment interactions causes wear and tear on the body's regulatory systems, which in turn can lead to disease outcomes and health disparities. METHODS: Using data from the National Health and Nutrition Examination Survey (NHANES) 1999-2004, this study examines AL in a nationally representative sample of women ≥18 years of age (n=5765). Measures of AL using 10 biomarkers representing cardiovascular, inflammatory, and metabolic system functioning were created. Multivariate negative binomial regression models were used, and predicted AL scores were computed. RESULTS: Black women had the highest predicted AL scores relative to other racial/ethnic groups, and a marked black/white gap in AL persisted across all age groups. Age by race/ethnicity interaction terms revealed significant racial/ethnic differences in AL patterns across age groups. Black women 40-49 years old had AL scores 1.14 times higher than white women 50-59 years old, suggesting earlier health deterioration. Mexican women not born in the United States had lower predicted AL scores than those born in the United States. CONCLUSIONS: This study provides one of the first descriptive profiles of AL among a nationally representative sample of adult women in the United States and presents racial/ethnic trends in AL across age groups that are useful for identifying demographically and clinically important subgroups at risk of having high cumulative physiological dysregulation.