In the January issue of the journal Sleep there are several studies relating sleep to telomere length (TL). Telomeres are the DNA-protein structures located like caps at the ends of chromosomes. They shorten with aging and may also be a marker of biological, not chronological, aging. They are believed to be involved in protecting the chromosome from inflammation and various stressors. In some studies, their diminishing length has been associated with diabetes and atherosclerosis.
I found one of these studies particularly interesting. In the study, 154 individuals aged 45 to 77 participated. The study demonstrated that poor sleepers, as defined by poor sleep quality or short duration (less than 7 hours per night), had significantly shorter telomere length. Even more interesting was the finding that in the older adults, adequate sleep was associated with telomere lengths comparable to middle-aged adults. The authors concluded that the study provides evidence that sleep is linked to cellular aging.
If this were the only study published on sleep and telomere length it would not be worth writing about, but it’s not. There have been several other studies demonstrating the relationship of sleep to telomere length. In another study published in in the journal Respiratory Medicine, persons with untreated sleep apnea were found to have shortened telomeres, too.
We know that telomeres shorten with aging. We also know that they shorten in response to chronic inflammation and oxidative stress. In fact, even the telomeres of newborns exposed to physiological stressors in utero have been found to be shorter. We also suspect that the shortening of telomeres can result in increased susceptibility to tissue damage.