OBJECTIVES

Sleep quality is a significant risk factor for age-related diseases. Although the mechanisms underlying the effects of sleep on age-related chronic conditions remain unclear, adverse effects of poor sleep quality on telomeres may be involved. Limited studies have examined associations between measures of sleep impairment and telomere length, but cross-sectional design, small sample sizes, and restricted study population limit the conclusions. This study extends the existing literature by using a longitudinal design and a large nationally representative sample of older adults in the United States to evaluate the independent association between sleep quality and telomere length.

METHODS

We adopted a retrospective cohort design; participants comprised 5,268 adults drawn from the Health and Retirement Study. We used the 2006 (baseline) and 2008 (follow-up) waves. Baseline sleep quality was assessed using 4 Likert scale questions (trouble falling asleep, waking up during the night, waking up too early and not able to sleep again, and feeling well rested in the morning). Telomere length was assessed using T/S ratio. The associations between sleep quality and T/S were assessed using multi-variable OLS regressions. All analyses were adjusted for demographics, lifestyle characteristics, psycho-social, and other factors.

RESULTS

Overall, 16% reported never feeling well rested in the morning; 26% of respondents always had trouble waking during the night, and 12.8% always had trouble waking up too early in the morning. Respondents who never felt rested in the morning had lower T/S ratio compared to those who always felt rested in the morning (Beta = -0.08, SE =0.03, p < 0.01).

CONCLUSIONS

In this cohort of older adults, an indicator of overall sleep quality was significantly and inversely associated with telomere length. These findings suggest a potential connection between impaired sleep and reduction in telomere length, a marker of cellular aging that has been linked to multiple chronic conditions.