Poor sleep shortens telomeres in older adults

Elderly adults who wake up not feeling well-rested are more likely to have shorter telomere lengths, a recent study has found. The overall composite measure of sleep quality, however, seems to be unrelated to telomere length.

Researchers performed a retrospective cohort study on 5,268 elderly adults (mean age, 67.0±10 years; 55 percent female), from whom baseline sleep parameters were measured using the Likert scale. Particularly, concerns about falling asleep, waking up during the night, waking up too early, and feeling well-rested in the morning were evaluated. Telomere length was measured from saliva samples.

Eighty percent of the participants said that they always or sometimes had at least one sleep problem, and 15 percent had trouble regarding all four sleep domains tested. Issues with sleep latency and early awakening, for example, was reported in 12.8 percent, while 30.4 percent and 29.9 percent noted difficulty falling asleep or waking too early, respectively.

Over 40 percent of the participants said that they never (16.2 percent) or only sometimes (24.8 percent) felt rested in the morning.

Researchers found that the overall composite of sleep quality, either as a binary or continuous variable, had no association with telomere length. Analysis by components showed that feeling rested in the morning was the only significant correlate of telomere length. That is, those who said they never or sometimes felt rested tended to have shorter telomeres (β, –0.04±0.02; p<0.05).

Notably, further adjusting for demographic factors, lifestyle, pain, health history, body mass index, and chronic conditions further strengthened this association (β, –0.08±0.02; p<0.01). All the other sleep domains were inversely correlated with telomere length, but failed to achieve significance.