The American National Sleep Foundation recommends 7-9 hours of sleep per day for adults 18 years of age and older. There has been increasing amount of research into the association between osteoporosis and sleep.

Longer sleep duration has been tied to increased risk of osteoporosis. A study by Chen and colleagues assessed the relationship between sleep, daytime nap duration, and osteoporosis. It was also investigated if they varied by sex, menopause, and sleep quality. The study included 8688 participants aged 40 years or above. Investigators noted that among postmenopausal women, risks of osteoporosis for sleep durations of 7–8 h/d, 9–10 h/d, and >10 h/d were 1.531 (1.106, 2.121), 1.360 (1.035, 1.787), and 1.569 (1.146, 2.149), respectively. The risks of osteoporosis for daytime nap durations of 30–60 min/d and longer than 60 min/d were 1.553 (1.212–1.989) and 1.645 (1.250–2.165), respectively.

Sleep durations of 7–8 h/d, 9–10 h/d, and >10 h/d, and longer daytime naps were therefore linked with higher risks of having osteoporosis. Higher frequency and longer duration of daytime napping were reported to be associated with lower femoral bone mineral density (BMD) in elderly women in a study published in Scientific Reports.

Shorter sleep duration, on the other hand, has also been linked with osteoporosis in postmenopausal women. A study published in the Journal of Bone and Mineral Research included 11,084 postmenopausal women from the Womens Health Initiative. Women with a sleep duration of ≤5 hours per night had significantly BMD compared to women who reported sleeping 7 hours per night. Adjusted multinomial models revealed that women with <5 hours of sleep per night had higher odds of low bone mass and osteoporosis of hip. Women sleeping ≤5 hours per night also had an increased risk for osteoporosis at the spine.

Another study has linked poor sleep quality with osteoporosis. Increased sleep disturbances seem to be a key factor in the association between poor sleep quality and osteoporosis.

Wang et al noted that both short and long sleep duration were associated with a significantly increased risk of osteoporosis in the middle-aged and elderly adults. The investigators noted a U-shaped dose-response relationship between sleep duration and risk of osteoporosis. The lowest risk was observed at a sleep duration of 8-9 h/day. In comparison with 8-h sleep duration per day, the pooled odds ratio for osteoporosis were found to be 1.03 for each 1-h reduction in individuals with shorter sleep duration and 1.01 for each 1-h increase in individuals with longer sleep duration.

Therefore, appropriate sleep duration could play a role in delaying or preventing osteoporosis.