19Objective 20 Obesity is associated with telomere attrition -a marker of cellular and biological aging. The US 21 has the highest proportion of obesity and is comprised of a racially/ethnic diverse population. 22 Little is known about the relationship between obesity and telomere attrition according to 23 race/ethnicity in the US. Our objective is to examine the differential association.
24Design and setting 25 The effect of body mass index (BMI), % total body fat (TBF) and waist circumference (WC) on 26 leukocyte telomere length (LTL) were examined as adiposity measures according to 27 race/ethnicity and sex specific race/ethnicity using separate adjusted linear regressions on a 28 sample of 4,919 respondents aged 20-84 years from cross-sectional 1999-2002 data using the US 29 National Health and Nutrition Examination Survey. Mediation analyses assessed health 30 behaviors associated with relationship between adiposity measures and LTL. 31 Main outcome measure 32 LTL 33 Results 34 African Americans (AA) experienced a 28% and 11% decrease in LTL associated with 35 increasing BMI and WC, (p=.02 and .03) respectively. Mexican Americans (MA) experienced a 36 33% decrease in LTL associated with increasing %TBF (p=.04). Whites experienced a 19%, 37 23%, and .08% decrease in LTL associated with increasing BMI, %TBF, and WC, (p=.05, .003, 38 .02) respectively. White men experienced a 26% decrease in LTL due to increasing BMI (p=.05). 39 AA women experienced a 41%, 44%, and 16% decrease in LTL due to increasing BMI, %TBF, 40 and WC, respectively (p=.007, .02, .04). White women experienced a 29% decrease in LTL 41 associated with increasing %TBF (p=.006). Selected health behaviors were associated with the 42 relationship between adiposity measures and LTL. 43 Conclusion 44 Overall, AA and Whites have worse cellular and biological aging related to collective adiposity 45 measures. According to sex, AA women experienced more deleterious cellular and biological 3 46 aging. Findings suggest tailored interventions to improve adverse behaviors that contribute to 47 obesity may improve telomere attrition in US adults. 48 Introduction 49 Secular rates of risk factors associated with cardiovascular disease (CVD) have been 50 declining among US adults across all racial/ethnic groups.[1] Obesity rates, on the other hand, 51 have increased. [2] Worldwide obesity has nearly tripled since 1975.[3] The US has the highest 52 proportion of obesity.[2] More than one-third of US adults are obese.[4] Prevalence rates differ 53 by race/ethnicity and by sex according to race/ethnicity.[4] Obesity is a major risk factor for 54 many age-related CVD chronic conditions such as hypertension, type 2 diabetes and 55 dyslipidemia which increases the risk for heart failure, heart attack and stroke.[5] It is the leading 56 cause of preventable deaths globally and occurs, in part, due to adverse modifiable lifestyle 57 behaviors such as sedentary physical activity and unhealthy diet.[3]58 Telomeres are the DNA-protein complex at the ends...