title: Differences in the effects of Asian dust on pulmonary function between adult patients with asthma and those with asthma-chronic obstructive pulmonary disease overlap syndrome.
abstract: BACKGROUND
  Asian dust (AD) exposure exacerbates pulmonary dysfunction in patients with asthma. Asthma-chronic obstructive pulmonary disease overlap syndrome (ACOS), characterized by coexisting symptoms of asthma and chronic obstructive pulmonary disease, is considered a separate disease entity. Previously, we investigated the effects of AD on pulmonary function in adult patients with asthma. Here, we present the findings of our further research on the differences in the effects of AD exposure on pulmonary function between patients with asthma alone and those with ACOS.
  
  
  METHODS
  Between March and May 2012, we conducted a panel study wherein we monitored daily peak expiratory flow (PEF) values in 231 adult patients with asthma. These patients were divided into 190 patients with asthma alone and 41 patients with ACOS in this study. Daily AD particle levels were measured using light detection and ranging systems. Two heavy AD days (April 23 and 24) were determined according to the Japan Meteorological Agency definition. A linear mixed model was used to estimate the association between PEF and AD exposure.
  
  
  RESULTS
  Increments in the interquartile range of AD particles (0.018 km(-1)) led to PEF changes of -0.50 L/min (95% confidence interval, -0.98 to -0.02) in patients with asthma alone and -0.11 L/min (-0.11 to 0.85) in patients with ACOS. The PEF changes after exposure to heavy AD were -2.21 L/min (-4.28 to -0.15) in patients with asthma alone and -2.76 L/min (-6.86 to 1.35) in patients with ACOS. In patients with asthma alone, the highest decrease in PEF values was observed on the heavy AD day, with a subsequent gradual increase over time.
  
  
  CONCLUSIONS
  Our results suggest that the effects of AD exposure on pulmonary function differ between patients with asthma alone and ACOS, with the former exhibiting a greater likelihood of decreased pulmonary function after AD exposure.
authors: Department of Respiratory Medicine and Rheumatology, Tottori University Faculty of Medicine, 36-1 Nishi-cho, Yonago, Japan.
authors: Masanari
authors: M
authors: Watanabe
authors: Department of Data Science, The Institute of Statistical Mathematics, 10-3 Midori-cho, Tachikawa, Tokyo, Japan.
authors: Hisashi
authors: H
authors: Noma
authors: Department of Respiratory Medicine and Rheumatology, Tottori University Faculty of Medicine, 36-1 Nishi-cho, Yonago, Japan.
authors: Jun
authors: J
authors: Kurai
authors: Department of Respiratory Medicine and Allergology, Kinki University Faculty of Medicine, 377-2 Ohnohigashi, Osakasayama, Japan.
authors: Hiroyuki
authors: H
authors: Sano
authors: Department of Respiratory Medicine and Rheumatology, Tottori University Faculty of Medicine, 36-1 Nishi-cho, Yonago, Japan.
authors: Yasuto
authors: Y
authors: Ueda
authors: Hosshoji Clinic, 286-4 Hosshoji, Saihaku, Japan.
authors: Masaaki
authors: M
authors: Mikami
authors: Saihaku Hospital, 397 Yamato, Saihaku, Japan.
authors: Hiroyuki
authors: H
authors: Yamamoto
authors: Department of Respiratory Medicine, Matsue Red Cross Hospital, 200 Horomachi, Matsue, Japan.
authors: Hirokazu
authors: H
authors: Tokuyasu
authors: Department of Respiratory Medicine, San-in Rosai Hospital, 1-8-1 Kaikeshinden, Yonago, Japan.
authors: Kazuhiro
authors: K
authors: Kato
authors: Department of Respiratory Medicine, Matsue City Hospital, 32-1 Noshirachou, Matsue, Japan.
authors: Tatsuya
authors: T
authors: Konishi
authors: Department of Respiratory Medicine, Matsue City Hospital, 32-1 Noshirachou, Matsue, Japan.
authors: Toshiyuki
authors: T
authors: Tatsukawa
authors: Department of Respiratory Medicine and Rheumatology, Tottori University Faculty of Medicine, 36-1 Nishi-cho, Yonago, Japan.
authors: Eiji
authors: E
authors: Shimizu
authors: The Board of Directors, Tottori University, 36-1 Nishi-cho, Yonago, Japan.
authors: Hiroya
authors: H
authors: Kitano
mesh_terms: D000328:Adult; D000368:Aged; D001249:Asthma / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology / Q000503:physiopathology; D004391:Dust / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D019570:Inhalation Exposure / Q000009:adverse effects / Q000032:analysis; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology / Q000503:physiopathology; D012129:Respiratory Function Tests / Q000379:methods; D012307:Risk Factors
chemical_list: D004391:Dust
keywords: Asian dust; asthma; asthma–chronic obstructive pulmonary disease overlap syndrome; peak expiratory flow; pulmonary function