Leukocyte telomere length and cardiovascular disease in African Americans: The Jackson Heart Study.

BACKGROUND AND AIMS: In European descent populations, shorter leukocyte telomere length (LTL) has been associated with subclinical atherosclerosis, cardiovascular disease (CVD), and mortality, while longer LTL has been associated with greater left ventricular hypertrophy. We evaluated the relationship of LTL with subclinical cardiovascular disease indices and incident clinical events and mortality in African Americans (AAs).

METHODS: Analyses were restricted to 2518 participants of the Jackson Heart Study (JHS) with LTL measured by Southern blot in baseline blood samples.

RESULTS: Adjusting for established CVD risk factors, longer LTL was significantly associated with lower prevalence of coronary artery calcification (CAC) (odds ratio (OR) = 0.810) per 1 kb increase in LTL; (95% confidence interval [CI] 0.656, 0.9998), p=0.0498). Longer LTL was also associated with higher ankle brachial index (ABI) (β = 0.023; (95% CI 0.004, 0.042), p=0.017) when comparing the highest to the lowest LTL quartile. There were no significant associations between LTL and abdominal aortic calcification, carotid intima-media thickness, or left ventricular mass. After a median follow-up of 9 years, longer LTL was associated with lower risk of incident ischemic stroke (hazard ratio (HR) 0.69 (95% CI 0.48, 0.99), p=0.044) and total mortality (HR 0.81 (95% CI 0.67, 0.97), p=0.026) in age and sex adjusted models, but these associations were no longer significant in fully adjusted models.

CONCLUSIONS: Among a community-based cohort of AAs, longer LTL was nominally associated with lower odds of CAC and increased ABI, indicative of decreased prevalence of subclinical atherosclerosis and peripheral arterial disease. These findings do not offer strong support for LTL as an independent biomarker of CVD risk in AAs.