Leisure-Time Screen-Based Sedentary Behavior and Leukocyte Telomere Length: Implications for a New Leisure-Time Screen-Based Sedentary Behavior Mechanism.

The field of sedentary behavior epidemiology is emerging. Short leukocyte telomere length (LTL) is a hallmark characteristic of aging, but LTL is also associated with morbidity and mortality independent of age. To my knowledge, only one study has examined the association between sedentary behavior and LTL. The purpose of this study was to examine the association between screen-based sedentary behavior and LTL. Data from the 1999-2002 National Health and Nutrition Examination Survey were used (N=6405; age, 20-84 years). Leisure-time screen-based sedentary behavior (television, video games, computer use) was assessed via questionnaire, and LTL was extracted from DNA in whole blood with the LTL assay performed using quantitative polymerase chain reaction. After adjustments (including age and physical activity), for every 1-hour increase in leisure-time screen-based sedentary behavior, participants had a 7% increased odds (odds ratio, 1.07; 95% CI, 1.00-1.13; P=.04) of having LTL in the lowest tertile (vs highest); leisure-time screen-based sedentary behavior was not associated with values in the middle (vs highest) tertile (odds ratio, 1.01; 95% CI, 0.95-1.07; P=.62). The results of this study revealed that greater leisure-time screen-based sedentary behavior is associated with shorter LTL.