論文No1733
Air Pollution Exposure Is Associated With Lower Lung Function, but Not Changes in Lung Function, in Patients With Idiopathic Pulmonary Fibrosis
Kerri A. Johannson, Eric Vittinghoff, Julie Morisset, Paul J. Wolters, Elizabeth M. Noth, John R. Balmes, Harold R. Collard
CHEST, Volume 154, Issue 1, p119–125, 2018.
＜背景＞
大気汚染曝露は特発性肺線維症(IPF)患者の急性増悪、疾患進行、死亡と関連している。
この研究の目的は、大気汚染がIPF患者の重症度、肺機能変化に及ぼす影響を調べることである。
＜方法＞
家庭スパイロメトリーと症状日記を使用して、25名のIPF患者が前向きにFVCを毎週、40週にわたって記録した。
居住地の週平均大気汚染評価として、地上レベルのオゾン(O3)、二酸素窒素(NO2)、微粒子(PM2.5, PM10)を評価した。
それぞれの大気汚染物質がその次の週の臨床測定値に影響するかを線形混合モデルで評価し、
β共変数、95%CIをlag timeを変えて検討した。
＜結果＞
平均FVC%が低い群は2-5週先行したPM10の増加と臨床結果が常に関連していた
(range, –0.46 to –0.39 [95% CI, –0.73 to –0.13]; P < .005)。
研究期間中の平均FVC%が低いと、NO2 (–0.45 [95% CI, –0.85 to –0.05]; P = .03),
PM2.5 (–0.45 [95% CI, –0.84 to –0.07]; P = .02),
PM10 (–0.57 [95% CI, –0.92 to –0.21]; P = .003)の平均値と逆相関していた。
週あたりのFVC変化、40週でのFVC変化は大気汚染曝露と関連しなかった。
＜感想＞
IPF患者において、大気汚染がひどいと肺機能が悪かったようですが、肺機能の変化とは関連しなかったようです。
Background
Air pollution exposure is associated with acute exacerbation, disease progression, and mortality in patients with idiopathic pulmonary fibrosis (IPF). The objective of this study was to describe the impact of air pollution exposures on disease severity, as well as changes in lung function, in patients with IPF.
Methods
Using home spirometers and symptom diaries, 25 patients with IPF prospectively recorded FVC weekly for up to 40 weeks. Residential addresses were geocoded to estimate weekly mean air pollution exposures for ground-level ozone (O3), nitrogen dioxide (NO2), and particulate matter < 2.5 or 10 μm in aerodynamic diameter (PM2.5 and PM10, respectively). The dependence of weekly clinical measurements on preceding levels of each pollutant was assessed with the use of linear mixed models, yielding beta-coefficients with 95% CIs, using varying lag times.
Results
Lower mean FVC % predicted was consistently associated with increased mean exposures to PM10 in the 2 to 5 weeks preceding clinical measurements (range, –0.46 to –0.39 [95% CI, –0.73 to –0.13]; P < .005). Lower mean FVC % predicted over the study period was inversely related to mean levels of NO2 (–0.45 [95% CI, –0.85 to –0.05]; P = .03), PM2.5 (–0.45 [95% CI, –0.84 to –0.07]; P = .02), and PM10 (–0.57 [95% CI, –0.92 to –0.21]; P = .003), averaged over the study. Weekly changes in FVC and changes over 40 weeks were independent of pollution exposures.
Conclusions
Higher air pollution exposures were associated with lower lung function, but not changes in lung function, in patients with IPF. Further studies are needed to characterize the mechanisms underlying this relationship.