Telomere length, health, and mortality in a cohort of older Black South African adults.

Telomere length (TL) may be a biomarker of aging processes as well as age-related diseases. However, most studies of TL and aging are conducted in high-income countries. Less is known in low- and middle-income countries (LMICs) such as South Africa, where life expectancy remains lower despite population aging. We conducted a descriptive analysis of TL in a cohort of older adults in rural South Africa. TL was assayed from venous blood draws using quantitative polymerase chain reaction (T/S ratio). We examined the correlation between TL and biomarkers, demographic characteristics, mental/cognitive health measures, and physical performance measures in a subsample of the Wave 1 2014-2015 "Health and Aging in Africa: A Longitudinal Study of an INDEPTH Community in South Africa" (HAALSI) cohort (n=510). We used logistic regression to measure the association between TL and mortality through Wave 3 (2021-2022). In bivariate analyses, TL was significantly correlated with age (r=-0.29, p-value<0.0001), self-reported female sex (r=0.13, p-value=0.002), mortality (r=-0.1297, p-value=0.003), diastolic blood pressure (r=0.09, p-value=0.037), pulse pressure (r=-0.09, p-value=0.045), and being a grandparent (r=-0.17, p-value=0.0001). TL was significantly associated with age (β=-0.003; 95% CI=-0.005, -0.003). TL was significantly associated in unadjusted multivariate analyses with mortality, but the relationship between TL and mortality was attenuated after adjusting for age (OR=0.19; 95% CI=0.03, 1.27) and other covariates (OR=0.17; 95% CI=0.02, 1.19). Our study is the first analysis of TL in an older adult South African population. Our results corroborate existing relationships between TL and age, sex, cardiometabolic disease, and mortality found in higher income countries.