E-Mail karger@karger.com Clinical Investigations Respiration 2014;88:234–243 DOI: 10.1159/000366064 Associations among Chronic Obstructive Pulmonary Disease and Sleep-Disordered Breathing in an Urban Male Working Population in Japan Masanori Azuma a Kazuo Chin b Chikara Yoshimura b Misa Takegami d, h Ken-ichi Takahashi i Kensuke Sumi f Takaya Nakamura g Yukiyo Nakayama-Ashida c Itsunari Minami c Sachiko Horita k Yasunori Oka l Toru Oga b Tomoko Wakamura e Shun-ichi Fukuhara d Michiaki Mishima a Hiroshi Kadotani j Departments of a Respiratory Medicine and b Respiratory Care and Sleep Control Medicine, and c Horizontal Medical Research Organization, Graduate School of Medicine, d Department of Epidemiology and Healthcare Research, Graduate School of Medicine and Public Health, and e Environmental Health Nursing, Graduate School of Medicine, Human Health Sciences, Kyoto University, f Department of Respiratory Medicine, National Hospital Organization Minami Kyoto Hospital, and g Department of Respiratory Medicine, Kyoto City Hospital, Kyoto, h Department of Prevalence Medicine and Epidemiologic Informatics, Research and Development Initiative Center, National Cerebral and Cardiovascular Center, Osaka, i Department of Respiratory Medicine, Otsu Red Cross Hospital, and j Department of Psychiatry, Shiga University of Medical Science, Otsu, k Department of Human Nursing, Faculty of Human Health, Sonoda Women’s University, Amagasaki, and l Department of Sleep Control Medicine, Graduate School of Medicine, Ehime University, Matsuyama, Japan graph 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 con- ducted. 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 sub- jects. 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 Key Words Chronic obstructive pulmonary disease · Sleep apnea · Overlap syndrome · Actigraph · Portable monitoring Abstract Background: There are few reports about sleep disturbanc- es in patients with chronic obstructive pulmonary disease (COPD) in Asian countries. Objectives: To investigate the as- sociations between sleep-disordered breathing (SDB) with hypoxemia and sleep quality, including sleep duration, in patients with COPD, we measured SDB and sleep quality in- cluding the objective sleep duration determined by an acti- Received: January 28, 2014 Accepted after revision: July 22, 2014 Published online: August 22, 2014 Kazuo Chin, MD, PhD Department of Respiratory Care and Sleep Control Medicine Graduate School of Medicine, Kyoto University Shogoin 54, Kawahara-cho, Sakyo-Ku, Kyoto 606-8507 (Japan) E-Mail chink  @  kuhp.kyoto-u.ac.jp © 2014 S. Karger AG, Basel 0025–7931/14/0883–0234$39.50/0 www.karger.com/res