Telomere length and MRI findings of vascular brain injury and central brain atrophy: The Strong Heart Study

Abstract

Telomeres are repeating regions of DNA that cap chromosomes. They shorten over mammalian lifespan, especially in presence of oxidative stress and inflammation. Telomeres may play a direct role in cell senescence, serving as markers of premature vascular aging. Leukocyte telomere length (LTL) may be associated with premature vascular brain injury and cerebral atrophy. However, reports have been inconsistent, especially among minority populations with heavy burden of illness related to vascular aging. We examined associations between LTL and magnetic resonance imaging in 363 American Indians aged 64–93 years from the Strong Heart Study cohort (1989–1991) and its ancillary examination Cerebrovascular Disease and its Consequences in American Indians (2010–2013). Our results show significant associations of LTL with ventricular enlargement and presence of white matter hyperintensities. Secondary models indicated renal function may mediate these associations, although small case numbers limited inference. Hypertension and diabetes showed little evidence of effect modification. Results were most extreme among participants who evinced the largest decline in LTL. Although this study was limited to cross-sectional comparisons, it represents the first consideration of associations between telomere length and brain aging in American Indians. Findings suggest a relationship between cell senescence vascular aging and severity of brain disease.