Associations of 24-hour sleep duration and CT-derived measurements of muscle and bone: The AGES-Reykjavik Study

Abstract

Background Although the importance of sleep on preservation of several physiological functions is well known, the relationship with the two interconnected tissues — muscle and bone is less understood. Objectives This study aimed to examine the association of 24-hour sleep duration with mid-thigh muscle composition and proximal femur volumetric bone mineral density (vBMD). Methods 2,438 men and 3326 women aged 66 to 96 years, residents in the Reykjavik area, were included in this cross-sectional study. Proximal femur integral vBMD, mid-thigh muscle area and muscle attenuation were assessed with computed tomography. Sleep and nap habits were assessed using a questionnaire. Results We found that after adjustment for age and BMI long sleep duration (>8 h/d) was negatively associated with thigh lean area in both men (B= −2.21, 95% confidence interval (CI): −4.01, −0.40) and women (B= −2.39, 95% CI: −3.75, −1.03) and with muscle attenuation (B= −0.95, 95% CI: −1.47, −0.43) only in women. After adjustments for age, health and lifestyle factors the association between long sleep duration and muscle lean area was attenuated and became nonsignificant while associations with muscle attenuation remained marginally significant (B= −0.51, 95% CI: −1.03, −0.002). Sleep duration was not associated with proximal femur integral vBMD in the multivariate models. Conclusion Long sleep duration, particularly in old women, can affect thigh muscle attenuation (increase in intramuscular fat). Whether optimization of sleep can ameliorate age-associated intramuscular or intermuscular adipose tissue warrants further studies.

Sleep duration and bone health measures in older men

“…The current literature on the association between selfreported sleep duration and BMD in men is mixed. Some studies found that both long [16,[25][26][27]30] and short [12,15,16,20,23] sleep duration are associated with low BMD; however, some studies did not show any association [11,13,29]. The lack of a significant association between BMD and sleep duration in older men in the current study is similar to findings from three prior studies in middle-aged and older men.…”

“…The lack of a significant association between BMD and sleep duration in older men in the current study is similar to findings from three prior studies in middle-aged and older men. An analysis of a similar-aged cohort of 2438 older men from the AGES-Reykjavik Study [11] identified no association between self-reported sleep duration (including naps) and volumetric BMD. No association was identified between self-reported sleep duration and BMD by calcaneal ultrasound in 3950 middle-aged Chinese men, where 8-9 h/ night was used as the reference group [13].…”

“…Human data are limited to mostly cross-sectional studies showing no association [11,12] or that both short [13][14][15][16][17][18][19][20][21][22][23] and long [13][14][15][16][17][24][25][26][27][28][29][30] sleep durations are associated with low BMD (as reviewed in [31]). Of the 20 studies published to date on the association between sleep duration and BMD in humans [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30], women comprised the majority of participants. All studies of men used subjective (self-reported) sleep duration and focused primarily on middle-aged adults when it is older men who are at highest risk of bone loss and fracture, and potential effect modifiers, such as vitamin D status, were not considered.…”

A cross-sectional analysis of the association between sleep duration and osteoporosis risk in adults using 2005–2010 NHANES

“…Both long 2 – 10 or short 4 , 5 , 7 , 8 , 11 – 13 self-reported sleep duration have been associated with low bone mineral density (BMD)/osteoporosis or fracture in the literature. Some, studies have not reported an association between sleep duration and BMD 14 , 15 . However, in these studies, the diagnostic methods used for osteoporosis varied considerably, including self-reported osteoporosis fracture, BMD by ultrasonic bone densitometry, peripheral quantitative computed tomography, or dual-energy X-ray absorptiometry (DXA) 2 – 10 .…”

The importance of the circadian system & sleep for bone health

“…Both long [13, 68–75] and short [70, 71, 74–80] self-reported sleep duration have been associated with low BMD/osteoporosis or fracture in previous, mostly cross-sectional, studies (Table 1). In addition, one study found that long (≥8 h) compared to short (<6 h) sleep duration was associated with an increased risk of osteoporosis [81] and two studies reported no association between sleep duration and BMD [82, 83]. A recent meta-analysis [84] determined that long sleep duration (defined as ≥8 h/day) was associated with a 22% higher risk of osteoporosis in middle-aged and elderly women (OR 1.22, 95% CI 1.06–1.38), while no association was identified for women with short sleep duration (defined as ≤7 h/day).…”