Risk factors for acute exacerbation of idiopathic pulmonary fibrosis: A systematic review and meta-analysis.
BACKGROUND
Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive fibrotic disease limited to the lungs. The course of disease varies widely, with some patients experiencing acute respiratory deterioration, a condition called acute exacerbations of IPF (AE-IPF). The risk factors contributing to AE-IPF are unclear. This systematic review and meta-analysis investigated the risk factors for AE-IPF.


METHODS
Studies of risk factors for AE-IPF were identified in Medline, EMBASE and Cochrane databases. Fixed effects models were used to calculate pooled relative risks and weighted mean differences (WMD).The meta-analysis included seven articles involving 14 risk factors for AE-IPF.


RESULTS
Risk factors for AE included reductions in vital capacity (VC; WMD - 10.58, 95% confidence interval (CI) -17.17 to - 3.99), forced vital capacity (FVC; WMD -6.02, 95%CI - 8.58 to - 3.47), total lung capacity (TLC; WMD -4.88, 95%CI -7.59 to - 2.17), and PaO2(WMD -4.19, 95%CI -7.66 to -0.71) and a higher alveolar-arterial oxygen difference (AaDO2; WMD 4.4, 95%CI 0.24 to 8.57). Mechanical procedures, higher serum KL-6 concentration and secondary pulmonary hypertension, might be risk factors for AE-IPF. In contrast, age, sex, body mass index (BMI), differences in diffusing lung capacity for carbon monoxide (DLCO), exposure to seasonal variations and air pollution, and virus infection might be unrelated to AE-IPF.


CONCLUSIONS
Poor pulmonary function, mechanical procedures, higher serum KL-6 and secondary pulmonary hypertension were associated with increased risks of AE-IPF.
Department of Occupational Medicine and Toxicology, Beijing Institute of Respiratory Medicine, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, China.
Meihua
M
Qiu
Department of Occupational Medicine and Toxicology, Beijing Institute of Respiratory Medicine, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, China.
Yuqing
Y
Chen
Department of Occupational Medicine and Toxicology, Beijing Institute of Respiratory Medicine, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, China.
Qiao
http://orcid.org/0000-0002-0932-0487
Q
Ye
D000208:Acute Disease; D001784:Blood Gas Analysis; D018450:Disease Progression; D006801:Humans; D054990:Idiopathic Pulmonary Fibrosis / Q000175:diagnosis* / Q000503:physiopathology; D008168:Lung / Q000000981:diagnostic imaging / Q000503:physiopathology*; D011379:Prognosis; D011653:Pulmonary Diffusing Capacity / Q000502:physiology*; D012307:Risk Factors; D014797:Vital Capacity / Q000502:physiology*
acute exacerbation; idiopathic pulmonary fibrosis; meta-analysis; pulmonary function; risk factors