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

• Main Authors: Watanabe M, Noma H, Kurai J, Sano H, Ueda Y, Mikami M, Yamamoto H, Tokuyasu H, Kato K, Konishi T, Tatsukawa T, Shimizu E, Kitano H
• Format: Article
• Language: English
• Published: Dove Medical Press 2016-01-01
• Series: International Journal of COPD
• Subjects: Asian dust; asthma; asthma–chronic obstructive pulmonary disease overlap syndrome; peak expiratory flow; pulmonary function
• Online Access: https://www.dovepress.com/differences-in-the-effects-of-asian-dust-on-pulmonary-function-between-peer-reviewed-article-COPD

Masanari Watanabe,1 Hisashi Noma,2 Jun Kurai,1 Hiroyuki Sano,3 Yasuto Ueda,1 Masaaki Mikami,4 Hiroyuki Yamamoto,5 Hirokazu Tokuyasu,6 Kazuhiro Kato,7 Tatsuya Konishi,8 Toshiyuki Tatsukawa,8 Eiji Shimizu,1 Hiroya Kitano9 1Department of Respiratory Medicine and Rheumatology, Tottori University Faculty of Medicine, 36-1 Nishi-cho, Yonago, 2Department of Data Science, The Institute of Statistical Mathematics, 10-3 Midori-cho, Tachikawa, Tokyo, 3Department of Respiratory Medicine and Allergology, Kinki University Faculty of Medicine, 377-2 Ohnohigashi, Osakasayama, 4Hosshoji Clinic, 286-4 Hosshoji, Saihaku, 5Saihaku Hospital, 397 Yamato, Saihaku, 6Department of Respiratory Medicine, Matsue Red Cross Hospital, 200 Horomachi, Matsue, 7Department of Respiratory Medicine, San-in Rosai Hospital, 1-8-1 Kaikeshinden, Yonago, 8Department of Respiratory Medicine, Matsue City Hospital, 32-1 Noshirachou, Matsue, 9The Board of Directors, Tottori University, 36-1 Nishi-cho, Yonago, Japan 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.Conclusion: 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. Keywords: Asian dust, asthma, asthma–chronic obstructive pulmonary disease overlap syndrome, peak expiratory flow, pulmonary function