title: Association between sleep duration and bone mineral density in Chinese women.
abstract: BACKGROUND
  Short sleep duration has been found to be closely related to several endocrine and metabolic dysfunctions. However, evidence of the association between insufficient sleep and bone health was limited.
  
  
  OBJECTIVE
  The present study was aimed to examine the relationships between sleep duration and bone mineral density (BMD) in Chinese women.
  
  
  METHODS
  Six hundred and two women aged 18-80 years were analyzed. Sleep duration was collapsed to form categories of 5h or less, 6h, 7h, 8h, and 9h or more. Total and regional BMD were measured using dual-energy X-ray absorptiometry. Multiple regression analysis was performed to examine the relationships between sleep duration categories and BMD.
  
  
  RESULTS
  Women with a short sleeping duration were more likely to have lower total and all body regional BMD after adjusting for potential covariates (all p values for trend <0.05). Compared to those who slept 8h, individuals who slept 5h or less and 6h had significant lower total and regional BMD (β coefficients ranged -0.07 to -0.11, all p<0.05). When further divided women into 18-44 years old and 45 years or older groups, and reran the regression models, the significant associations between BMD and sleep duration were only observed in 45 years or older group.
  
  
  CONCLUSIONS
  Significant variations in total and regional BMD with sleep duration were observed in women. Decreased sleep duration closely associated with lower BMD, especially in middle-age and elderly women. These findings may lead to the development of better preventive approaches to osteoporosis in women through identification of potential modifiable risk factors.
authors.affiliation: Obesity and Body Composition Research Center, Zhejiang University School of Public Health, Hangzhou, China. fxh9210@163.com
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Fu
authors.forename: Xinyu
authors.initials: X
authors.lastname: Zhao
authors.forename: Han
authors.initials: H
authors.lastname: Lu
authors.forename: Fan
authors.initials: F
authors.lastname: Jiang
authors.forename: Xiaoguang
authors.initials: X
authors.lastname: Ma
authors.forename: Shankuan
authors.initials: S
authors.lastname: Zhu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015519:Bone Density; D002681:China; D005260:Female; D006801:Humans; D008875:Middle Aged; D012044:Regression Analysis; D012890:Sleep; D013997:Time Factors; D055815:Young Adult