Abstract P123: Life’s Simple 7 and Leukocyte Telomere Length in American Indians: The Strong Heart Study

Background: Telomeres are the repeated DNA sequences and associated proteins at the end of chromosomes. Telomere length shortens progressively with each cell division and has been used as a marker of biological aging. Shorter telomere length has been associated with CVD and its risk factors. The AHA’s 2020 impact goal, summarized in Life’s Simple 7 (LS7), has also been associated with reduced risk of CVD, but no study has examined the potential influence of these goals on biological aging assessed by telomere length. Objective: To determine the association of LS7 with telomere length in American Indians, a minority population suffering from disproportionately high rates CVD and diabetes. Methods: Leukocyte telomere length (LTL) was measured by quantitative PCR in 3,577 American Indians in the Strong Heart Study, a population-based study of CVD and its risk factors in 13 tribes in Arizona, North/South Dakota, and Oklahoma. LS7 metrics include 3 health factors (blood pressure, cholesterol, blood glucose) and 4 behavioral factors (smoking, physical activity, diet, and BMI). Each of the 7 individual components was categorized as poor, intermediate, or ideal health in accordance with the AHA’s LS7 goals. A composite score ranging from 0 to 7 was created based on the total number of ideal cardiovascular health metrics. This score was further categorized as below average (0-1), average (2-3) and above average (≥4) cardiovascular health. Linear regression model was used to test the association of each individual metric with LTL, adjusting for age and all other metrics. The association of LTL with the composite score was similarly examined. Results: The mean age was 40. Ideal levels of the LS7 factors were observed in 42% for smoking, 11% for physical activity, 17% for BMI, 0% for diet, 40% for blood pressure, 73% for cholesterol, and 58% for fasting glucose. About 26%, 53% and 21% of the participants had below average, average, and above average cardiovascular health, respectively. LTL was negatively associated with BMI (P=0.003) after adjusting for age and all other six factors. No independent association was observed between LTL and the other individual health factors or behaviors. Compared with participants with below average composite score, those with above average score had significantly longer LTL (β = 0.041, P=0.001) after adjusting for age. This association, however, was substantially attenuated after excluding participants with diabetes (β = 0.027, P=0.05). Conclusions: Compared to the general U.S. population, American Indians had low rate of ideal cardiovascular health for 5 out of the Life’s Simple 7 factors, including smoking, BMI, physical activity, diet, and fasting glucose. The achievement of 4 or more Life’s Simple 7 goals is associated with longer telomere length, suggesting that a favorable cardiovascular risk profile may promote healthy aging, thereby reducing cardiovascular risk.