title: High prevalence of obstructive sleep apnea and its association with renal function among nondialysis chronic kidney disease patients in Japan: a cross-sectional study.
abstract: OBJECTIVE
  Obstructive sleep apnea (OSA) affects one of five adults in the general population. Although a high prevalence of OSA has been reported among dialysis patients, the association between nondialysis chronic kidney disease (CKD) and OSA has not been fully investigated. This cross-sectional study aimed to investigate the prevalence of OSA among nondialysis CKD patients in Japan and the association between renal function and OSA.
  
  
  METHODS
  Consecutive nondialysis CKD patients hospitalized mainly for CKD educational program, regardless of their sleep complaints, were enrolled. The diagnosis of OSA and its severity were measured using a type 3 portable monitor.
  
  
  RESULTS
  Overall (n=100, 68.0% male, median age 66.5 years, body mass index [BMI] 23.1 kg/m(2), estimated GFR [eGFR] 28.5 ml/min per 1.73 m(2)), 65% were diagnosed as OSA: mild OSA (apnea-hypopnea index [AHI] 5.0 to 14.9) in 32%, moderate OSA (AHI 15.0 to 29.9) in 25%, and severe OSA (AHI ≥ 30.0) in 8%. Multivariate logistic regression analysis revealed that a 10-ml/min per 1.73 m(2) decrease in eGFR was associated with a 42% increased odds of OSA after adjustment for age, BMI, and diabetes mellitus. Moreover, in a generalized linear model, eGFR was inversely correlated with AHI after adjustment for covariates.
  
  
  CONCLUSIONS
  This study demonstrated a high prevalence of OSA among nondialysis CKD patients in Japan and that the increased risk of OSA was significantly associated with decreased GFR among these patients. Further investigations are warranted to determine OSA's direct influence on cardiovascular disease.
authors.affiliation: Department of Kidney Disease and Hypertension, Osaka General Medical Center, 3-1-56 Bandaihigashi, Osaka 558-8558, Japan. yusuke7771@gmail.com
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Sakaguchi
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Shoji
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kawabata
authors.forename: Kakuya
authors.initials: K
authors.lastname: Niihata
authors.forename: Akira
authors.initials: A
authors.lastname: Suzuki
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Kaneko
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Okada
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Isaka
authors.forename: Hiromi
authors.initials: H
authors.lastname: Rakugi
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Tsubakihara
mesh_terms: D000368:Aged; D044466:Asian People / Q000706:statistics & numerical data*; D002318:Cardiovascular Diseases / Q000208:ethnology; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D051436:Renal Insufficiency, Chronic / Q000208:ethnology*; D012307:Risk Factors; D020181:Sleep Apnea, Obstructive / Q000208:ethnology*