title: Association between body size phenotype and sleep duration: Korean National Health and Nutrition Examination Survey V (KNHANES V).
abstract: OBJECTIVE
  Recent studies reported the presence of unique subsets of body size phenotypes that are more susceptible or more resistant to the development of obesity-associated metabolic disorders, although the underlying mechanism is not yet fully elucidated. We investigated the association between body size phenotypes and sleep duration after adjusting potential confounding factors.
  
  
  METHODS
  We analyzed data from the Korean National Health and Nutrition Examination Survey V (KNHANES V), a nation-wide, population-based health survey including 9077 Korean adults. The average amount of sleep per night was categorized as: ≤6, 7, 8, and ≥9 h. Body size phenotypes were classified based on body mass index (BMI) and presence of metabolic syndrome; metabolically healthy and normal weight (MHNW), metabolically abnormal but normal weight (MANW), metabolically healthy but obese (MHO), and metabolically abnormal obese (MAO).
  
  
  RESULTS
  According to sleep duration, there were significant differences in age, gender, BMI, waist circumference, and blood pressure (all P <0.05). Multivariate analysis showed that obese groups (MHO and MAO) had significantly shorter sleep durations than non-obese groups (MHNW and MANW) (6.78±0.04 vs. 6.93±0.03, P <0.001). Sleep duration was significantly different according to body size phenotype, irrespective of confounding factors, such as age, gender, smoking status, alcohol consumption, physical activity, income, and education (MHO; 6.73±0.05, MAO; 6.82±0.05, MHNW; 6.94±0.04, and MANW; 6.91±0.05; P <0.001).
  
  
  CONCLUSIONS
  Sleep duration is independently associated with body size phenotype after adjusting for confounding factors in the Korean population.
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Korea University, Seoul, Korea.
authors.forename: Ja Young
authors.initials: JY
authors.lastname: Ryu
authors.affiliation: Biostatistical Consulting Unit, Soonchunhyang University Medical Center, Seoul, Korea.
authors.forename: Ji Sung
authors.initials: JS
authors.lastname: Lee
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Korea University, Seoul, Korea.
authors.forename: Ho Cheol
authors.initials: HC
authors.lastname: Hong
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Korea University, Seoul, Korea.
authors.forename: Hae Yoon
authors.initials: HY
authors.lastname: Choi
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Korea University, Seoul, Korea.
authors.forename: Hye Jin
authors.initials: HJ
authors.lastname: Yoo
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Korea University, Seoul, Korea.
authors.forename: Ji A
authors.initials: JA
authors.lastname: Seo
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Korea University, Seoul, Korea.
authors.forename: Sin Gon
authors.initials: SG
authors.lastname: Kim
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Korea University, Seoul, Korea.
authors.forename: Nan Hee
authors.initials: NH
authors.lastname: Kim
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Korea University, Seoul, Korea.
authors.forename: Sei Hyun
authors.initials: SH
authors.lastname: Baik
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Korea University, Seoul, Korea.
authors.forename: Dong Seop
authors.initials: DS
authors.lastname: Choi
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Korea University, Seoul, Korea. Electronic address: medica7@gmail.com.
authors.forename: Kyung Mook
authors.initials: KM
authors.lastname: Choi
mesh_terms: D000328:Adult; D044466:Asian People / Q000706:statistics & numerical data*; D015992:Body Mass Index; D049628:Body Size; D001835:Body Weight; D015986:Confounding Factors, Epidemiologic; D005260:Female; D006306:Health Surveys; D006801:Humans; D008297:Male; D008659:Metabolic Diseases / Q000453:epidemiology; D024821:Metabolic Syndrome / Q000453:epidemiology; D009749:Nutrition Surveys; D009765:Obesity / Q000453:epidemiology / Q000378:metabolism; D010641:Phenotype; D056910:Republic of Korea / Q000453:epidemiology; D012890:Sleep
keywords: Body mass index; Body size phenotypes; Metabolic syndrome; Obesity; Sleep duration