Objective: This study examined the relationships of high-density lipoprotein cholesterol (HDL-C) with LTL and the rate of its shortening.
Background: Diminished levels of HDL-C are associated with an increased risk for atherosclerosis. Shortened leukocyte telomere length (LTL) also entails an increased atherosclerotic risk.
Methods: We studied 472 Whites and 190 African Americans (AfAs) enrolled in the Bogalusa Heart Study. Subjects were examined serially 3-13 times for HDL-C over an average period of 27.8 years from childhood through young adulthood. LTL was measured twice during adulthood at a mean age of 31.5 years (baseline exam) and 37.8 years (follow-up exam). HDL-C trajectories with age were constructed and the area under the curve (AUC) was used as a measure of cumulative HDL-C levels.
Results: Multivariate regression analyses showed that LTL was positively associated with HDL-C in childhood (regression coefficient (bp per mg/dL) beta=3.1, p=0.024), adulthood (beta=4.4, p=0.058) and AUC from childhood to adulthood (beta=12.2, p=0.0004) in the combined sample of AfAs and Whites. The association between LTL and HDL-C AUC was stronger in females (beta=18.5, p<0.001) than in males (beta=2.9, p=0.590) (difference in slopes p=0.037). A slower rate of LTL shortening per year was associated with higher HDL-C AUC in the total sample (p=0.033), adjusting for baseline LTL.
Conclusions: As HDL-C exerts anti-oxidant and anti-inflammatory effects and LTL registers the accruing burden of oxidative stress and inflammation, the association between HDL-C and LTL might be explained by the lifelong status of oxidative stress and inflammation.