title: Associations among chronic obstructive pulmonary disease and sleep-disordered breathing in an urban male working population in Japan.
abstract: BACKGROUND
  There are few reports about sleep disturbances in patients with chronic obstructive pulmonary disease (COPD) in Asian countries.
  
  
  OBJECTIVE
  To investigate the associations between sleep-disordered breathing (SDB) with hypoxemia and sleep quality, including sleep duration, in patients with COPD, we measured SDB and sleep quality including the objective sleep duration determined by an actigraph and portable monitoring.
  
  
  METHODS
  A cross-sectional epidemiological health survey of 303 male employees (means ± SD: age 43.9 ± 8.2 years; BMI 24.0 ± 3.1) was conducted. Sleep quality was measured using the Epworth Sleepiness Scale (ESS) and the Pittsburgh Sleep Quality Index (PSQI). A respiratory disturbance index (RDI) ≥5 indicated SDB.
  
  
  RESULTS
  Nineteen subjects (6.3%) had COPD. Among these, 11 (3.6%) had COPD with SDB (overlap syndrome). Sleep duration, ESS, and PSQI scores were not significantly different between COPD patients and normal control subjects. However, COPD patients had significantly longer sleep latency (p = 0.019), a lower sleep efficiency (p = 0.017), and a higher sleep fragmentation index (p = 0.041) and average activity (p = 0.0097) during sleep than control subjects. They also had a significantly higher RDI and more severe desaturation during sleep than control subjects (p < 0.01). The differences remained after adjustment for age and BMI but disappeared following adjustment for RDI.
  
  
  CONCLUSIONS
  COPD patients with even mild-to-moderate airflow limitations had nocturnal desaturation and RDI-related impaired sleep quality without significant symptoms.
authors.affiliation: Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Masanori
authors.initials: M
authors.lastname: Azuma
authors.forename: Kazuo
authors.initials: K
authors.lastname: Chin
authors.forename: Chikara
authors.initials: C
authors.lastname: Yoshimura
authors.forename: Misa
authors.initials: M
authors.lastname: Takegami
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Takahashi
authors.forename: Kensuke
authors.initials: K
authors.lastname: Sumi
authors.forename: Takaya
authors.initials: T
authors.lastname: Nakamura
authors.forename: Yukiyo
authors.initials: Y
authors.lastname: Nakayama-Ashida
authors.forename: Itsunari
authors.initials: I
authors.lastname: Minami
authors.forename: Sachiko
authors.initials: S
authors.lastname: Horita
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Oka
authors.forename: Toru
authors.initials: T
authors.lastname: Oga
authors.forename: Tomoko
authors.initials: T
authors.lastname: Wakamura
authors.forename: Shun-Ichi
authors.initials: S
authors.lastname: Fukuhara
authors.forename: Michiaki
authors.initials: M
authors.lastname: Mishima
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kadotani
mesh_terms: D056044:Actigraphy; D000328:Adult; D003430:Cross-Sectional Studies; D004651:Employment / Q000706:statistics & numerical data*; D006801:Humans; D000860:Hypoxia / Q000453:epidemiology; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D029424:Pulmonary Disease, Chronic Obstructive / Q000453:epidemiology*; D012891:Sleep Apnea Syndromes / Q000453:epidemiology; D020181:Sleep Apnea, Obstructive / Q000453:epidemiology*; D012892:Sleep Deprivation / Q000453:epidemiology; D013997:Time Factors; D014505:Urban Population / Q000706:statistics & numerical data*