title: Sleep duration and quality in relation to non-alcoholic fatty liver disease in middle-aged workers and their spouses.
abstract: OBJECTIVE
  Although accumulated evidence implies that short sleep duration and poor sleep quality may lead to an altered metabolic milieu, potentially triggering the development of non-alcoholic fatty liver disease (NAFLD), no studies have explored this association. This study sought to examine whether short sleep duration or poor sleep quality is associated with NAFLD in the general population.
  
  
  METHODS
  We assessed sleep duration and quality using the Pittsburgh Sleep Quality Index in 69,463 middle-aged workers and their spouses and carried out biochemical and anthropometric measurements. The presence of fatty liver was determined using ultrasonographic findings. Logistic regression models were used to evaluate the association of sleep duration and quality with NAFLD, after adjusting for potential confounders.
  
  
  RESULTS
  After controlling for the relevant confounding factors (age, alcohol intake, smoking, physical activity, systolic blood pressure, education level, marital status, presence of job, sleep apnea, and loud snoring), the adjusted odds ratio (95% confidence interval) for NAFLD comparing sleep duration ≤5 h to the reference (>7h) was 1.28 (1.13-1.44) in men and 1.71 (1.38-2.13) in women. After further adjustments for BMI, this association was not significant in men (OR: 1.03, 95% CI: 0.90-1.19) but remained significant in women (OR: 1.59, 95% CI: 1.23-2.05). The multivariate-adjusted odds ratio comparing participants with poor sleep quality vs. participants with good sleep quality was 1.10 (95% CI 1.02-1.19) and 1.36 (95% CI 1.17-1.59) in men and women, respectively.
  
  
  CONCLUSIONS
  In the middle-aged, general population, short sleep duration, and poor sleep quality were significantly associated with an increased risk of NAFLD. Prospective studies are required to confirm this association.
authors.affiliation: Center for Cohort Studies, Total Healthcare Center, Kangbuk Samsung Hospital, Sungkyunkwan University, School of Medicine, Seoul, Republic of Korea.
authors.forename: Chan-Won
authors.initials: CW
authors.lastname: Kim
authors.forename: Kyung Eun
authors.initials: KE
authors.lastname: Yun
authors.forename: Hyun-Suk
authors.initials: HS
authors.lastname: Jung
authors.forename: Yoosoo
authors.initials: Y
authors.lastname: Chang
authors.forename: Eun-Suk
authors.initials: ES
authors.lastname: Choi
authors.forename: Min-Jung
authors.initials: MJ
authors.lastname: Kwon
authors.forename: Eun-Hyun
authors.initials: EH
authors.lastname: Lee
authors.forename: Eui Jeong
authors.initials: EJ
authors.lastname: Woo
authors.forename: Nan Hee
authors.initials: NH
authors.lastname: Kim
authors.forename: Hocheol
authors.initials: H
authors.lastname: Shin
authors.forename: Seungho
authors.initials: S
authors.lastname: Ryu
mesh_terms: D000328:Adult; D015992:Body Mass Index; D005234:Fatty Liver / Q000000981:diagnostic imaging / Q000209:etiology* / Q000473:pathology; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D065626:Non-alcoholic Fatty Liver Disease; D056910:Republic of Korea; D012307:Risk Factors; D012727:Sex Characteristics; D012893:Sleep Wake Disorders / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology; D018454:Spouses; D011795:Surveys and Questionnaires; D014463:Ultrasonography
keywords: ALT; BMI; CI; FBG; HDL-C; HOMA-IR; IR; LDL-C; NAFLD; Non-alcoholic fatty liver disease; Obesity; Sleep duration; Sleep quality; alanine aminotransferase; body mass index; confidence interval; fasting blood glucose; high sensitivity-C reactive protein; high-density lipoprotein-cholesterol; homeostasis model assessment of insulin resistance; hsCRP; insulin resistance; low-density lipoprotein-cholesterol; non-alcoholic fatty liver disease