title: Sleep duration associated with body mass index among Chinese adults.
abstract: OBJECTIVE
  The objective of this study was to investigate the relationship between sleep duration and obesity among Chinese adults.
  
  
  METHODS
  A community-based cross-sectional study was conducted among Chinese adults in 2008. In total, 3225 participants were selected by a multistage cluster sampling method. Self-reported sleep duration was measured by a standardized questionnaire. Logistic regression models were used to estimate the odds ratios (ORs) (95% confidence intervals, CIs) of obesity with sleep duration, separated by gender, and adjusted for age, education, occupation, marriage, smoking, drinking, body pain, and health status.
  
  
  RESULTS
  The mean sleep duration was 7.8 h. Among the 2962 participants, 7.2% had short sleep duration (≤6 h/day). There were 171 obese participants (5.7%) in this population. After adjustment for age, short sleep duration (<6 h) was significantly associated with obesity among men (OR: 2.15; 95% CI: 1.193.90), but not among women; additional adjustment for potential confounders did not attenuate the association among men. Increasing sleep duration (a continuous variable) was significantly and negatively associated with obesity in women after adjustment for education level, occupation, marital status, smoking, drinking, body pain, and health status. The adjusted OR per-hour increase in sleep duration was 0.74 (0.56-0.97) for obesity, suggesting that for a 1-h increase in sleep duration among women, obesity risk decreased by 26%.
  
  
  CONCLUSIONS
  Short sleep duration was associated with increasing obesity in Chinese men, and sleep duration was associated with obesity in Chinese women, although the underlying mechanism is unclear. This possible gender difference warrants further studies.
authors: School of Food Science, Guangdong Pharmaceutical University, Zhongshan, Guangdong, China; Department of Global Environmental Health Sciences, School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA, USA.
authors: Wenjie
authors: W
authors: Sun
authors: Department of Preventive Medicine, School of Public Health, Wannan Medical College, Wu Hu, Anhui, China; Laboratory for Environment and Health, School of Earth and Environment, Anhui University of Science and Technology, Huainan, Anhui, China.
authors: Yuee
authors: Y
authors: Huang
authors: Department of Epidemiology and Health Statistics, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
authors: Zengzhen
authors: Z
authors: Wang
authors: Department of Epidemiology, School of Public Health, Jilin University, Changchun, Jilin, China.
authors: Yaqin
authors: Y
authors: Yu
authors: Department of Infectious Diseases, School of Medicine, Tulane University, New Orleans, LA, USA.
authors: Abby
authors: A
authors: Lau
authors: Heart and Vascular Institute, School of Medicine, Tulane University, New Orleans, LA, USA.
authors: Gholam
authors: G
authors: Ali
authors: Department of Epidemiology, School of Public Health, Medical College of Soochow University, Suzhou, Jiangsu, China.
authors: Ping
authors: P
authors: Huang
authors: Department of Epidemiology, School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA 70112, USA.
authors: Yunlong
authors: Y
authors: Geng
authors: Department of Epidemiology, School of Public Health, Medical College of Soochow University, Suzhou, Jiangsu, China; Department of Epidemiology, School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA 70112, USA. Electronic address: xutan@suda.edu.cn.
authors: Tan
authors: T
authors: Xu
authors: Department of Epidemiology and Statistics, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing 100005, China. Electronic address: guangliang_shan@hotmail.com.
authors: Guangliang
authors: G
authors: Shan
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D015992:Body Mass Index; D002681:China / Q000453:epidemiology; D003430:Cross-Sectional Studies; D005260:Female; D006304:Health Status; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications; D012737:Sex Factors; D012890:Sleep; D012892:Sleep Deprivation / Q000150:complications; D011795:Surveys and Questionnaires; D055815:Young Adult
keywords: BMI; Chinese; Obesity; Sleep duration