Routinely sleeping as little as 5 to 6.5 hours per night appears to have no affect on longevity, according to results from a subset of women who participated in the Women’s Health Initiative.
The finding conflicts with many previously published studies which suggest that sleeping 6.5 to 7.5 hours per night is associated with optimal survival.
For the study, which was reported online Sept. 30, 2010, in the journal Sleep Medicine, researchers led by Dr. Daniel F. Kripke, professor emeritus of psychiatry at the University of California, San Diego, revisited original research conducted between 1995 and 1999, in which 459 San Diego women aged 50-81 years were monitored with actigraphy for 1 week to determine if nightly sleep duration was associated with mortality.
Fourteen years later, the researchers were able to locate and evaluate 444 of the women initially enrolled in the study. Of these, 86 had died (J. Sleep Med. 2010 Sept. 30 [doi: 10.1016/j.sleep.2010.04.016]).
Dr. Kripke and his associates found that the best rates of survival occurred among women who slept 5 to 6.5 hours per night. “Women who slept less than 5 hours a night or more than 6.5 hours were less likely to be alive at the 14-year follow-up,” Dr. Kripke said in a prepared statement.
It’s unclear if any of the study participants were enrolled in medical residency programs at the time.
So, be honest here. On average, how many hours per night of sleep do you get?
— Doug Brunk (onTwitter@dougbrunk)