Social-demographics, health behaviors, and telomere length in the Mexican American Mano a Mano Cohort

In the current study, we examined cross-sectional associations among socialdemographics, lifestyle behaviors, and relative telomere length (RTL) in peripheral blood leukocytes, as well as longitudinal relationships among major chronic diseases, weight gain, and RTL, among 12,792 Mexican Americans aged 20 to 85 years in the Mano-A-Mano, the Mexican American Cohort. As expected, RTL was inversely correlated with age (ρ=-0.15, ρ < 0.001). In the multivariate analysis, we found that RTL was positively correlated with levels of education (ρ=0.021), self-insurance (ρ=0.041), body mass index (BMI) (ρ < 0.001), and sleeping time per day (ρ for trend < 0.001), and RTL was inversely correlated with sitting time per day (ρ for trend =0.001). In longitudinal analysis, we found that longer RTL was modestly but positively associated with increased risks of overall cancer (adjusted hazard ratio (adj.HR)=1.05, 95% conference interval (95%CI)=1.02-1.09). In quartile analysis, 4^th quartile (longest RTL) was associated with 1.53-fold increased risk of overall cancer (adj.HR=1.53, 95%CI=1.11-2.10), compared to 1^st quartile (shortest RTL). RTL was reversely associated with the risk of type-2 diabetes (adj.HR=0.89, 95%CI=0.82- 0.94). In quartile analysis, 4^th quartile (longest RTL) was associated with 48% decreased risk of typle-2 diabetes (adj.HR=0.52, 95%CI=0.32-0.70), compared to 1^st quartile (shortest RTL). In addition, longer RTL was a positive predictor of at least 10% weight gain (adj.HR=1.03, 95%CI=1.00-1.05). In summary, our results in Mexican Americans support the notion that telomere length is a biological mechanism by which social demographics and health behaviors "get under the skin" to affect health.