Neighborhood built environment and leukocyte telomere length among African American adults in the Jackson Heart Study.

Abstract

Background: Evidence on the relationship between the built environment and leukocyte telomere length (LTL), a biomarker of cellular aging, is limited and inconsistent, with intermediary factors and the moderating role of sex remaining understudied.

Purpose: This study examined the direct associations between built environment factors and LTL and evaluated whether these associations were mediated by physical activity (PA) and diet and varied by sex.

Methods: Cross-sectional data came from the Jackson Heart Study (baseline, 2000-04; n = 2174; mean age = 54.7 years; 55.2% females). LTL was measured from blood using Southern blot analysis. Built environment measures included unfavorable food stores, population density, PA facilities, and popular walking destinations. Total PA and healthy eating diet scores were tested as mediators. Linear regression was used to examine the direct and indirect associations between each built environment factor and LTL adjusted for covariates. All analyses were stratified by sex.

Results: Unfavorable food stores, population density, PA facilities, and popular walking destinations were directly associated with LTL (β = -.05, 95% confidence interval [CI] = -0.08 to -0.01; β = -.06, 95% CI = -0.09 to -0.02; β = -.04, 95% CI = -0.07 to -0.01; and β = -.05, 95% CI = -0.08 to -0.02, respectively). When stratified by sex, similar associations were observed in females but not in males. No statistically significant mediation through PA or diet was observed in overall or sex-stratified analyses.

Conclusions: Built environment appears to be directly associated with shorter LTL in African American females, suggesting an increased disease risk. Similar studies could be extended to other racial and/or ethnic groups to determine the generalizability of the current findings.