Abstract: Objective To evaluate the efficacy of angiotensin converting enzyme inhibitor (ACEI) and angiotensin receptor blocker (ARB) in the treatment of idiopathic pulmonary fibrosis through the method of system evaluation. Methods A computer-based online search of Pubmed, Embase, Cochrane Library, CNKI, CBM and Wanfang were used for database retrieval. Revman 5.0 was used to assess the bias of the included studies. The Stata 14.0 was used to evaluate the extraction indexes of efficacy, p (O2), p (CO2), DLco, FEV1 and VC. GRADE score was used to evaluate the level of evidence. Results A total of 17 articles (related with 1 381 patients) were included in this study, including 14 studies using ARB and 3 studies using ACEI. Compared with the control group ACEI and ARB drugs showed advantages in the treatment of pulmonary fibrosis (RR=1.34, 95%CI: 1.24-1.44, Z=7.81, P＜0.001). Auxiliary index analysis showed that the test groups were treated with enalapril (SMD=0.72, 95%CI： 0.21-1.22, Z=2.77, P=0.006), telmisartan (SMD=3.86, 95%CI: 2.44-5.27, Z=5.35, P＜0.001), valsartan (SMD=1.94, 95%CI： 1.33-2.55, Z=6.27, P＜0.001) and captopril (SMD=0.60, 95%CI： 0.11- 1.09, Z=2.41, P=0.016), the p(O2) levels were significantly improved in patients ≥65 years old (SMD=0.76, 95%CI： 0.52- 1.00, Z=6.18, P＜0.001) and patients ＜ 65 years old (SMD=3.97, 95% CI： 2.61- 5.32, Z=5.73, P＜0.001), and disease duration ≥ 5 years (SMD=1.39, 95%CI： 0.45-2.33, Z=2.89, P=0.004) and disease duration ＜ 5 years (SMD=3.26, 95%CI： 2.06-4.46, Z=5.34, P＜0.001) compared with those of control group (SMD=2.95, 95%CI： 1.95-3.94, Z=5.82, P＜0.001). The curative effect of telmisartan was better than that of other drug groups (P < 0.001), and which was much better for patients under 65 years old (P < 0.001). There was no significant difference in the disease duration between two groups (P= 0.307). The p (CO2) levels were significantly improved in patients treated with telmisartan [SMD=-12.94， 95%CI： (-14.01)- (-11.86)， Z=23.51， P＜0.001), valsartan [SMD=-1.95， 95%CI： (-2.56)-(-1.34)，Z=6.29， P＜0.001] compared with those of control group [SMD=-11.13， 95%CI： (-17.03)-(-5.24)， Z=3.70， P＜0.001]. The effect of telmisartan was better than that of valsartan (P < 0.001). In addition, values of DLco (SMD=0.64, 95%CI： 0.45-0.83, Z=6.72, P＜0.001), FEV1 (SMD=1.19, 95% CI： 0.52- 1.86, Z=3.47, P＜0.001) and VC (SMD=0.51, 95% CI： 0.16- 0.85, Z=2.85, P=0.004) were improved in test group compare with those of control group. And the GRADE scores of relevant indexes were low quality to moderate quality. Conclusion ACEI and ARB can improve the efficacy, the p (O2) and p (CO2) in the treatment of pulmonary fibrosis. Patients with age <65 years old and treated with telmisartan have the best curative effect, and which is not related to the disease duration.

Key words: pulmonary fibrosis, Meta- analysis, lung cystic fibrosis, angiotensin converting enzyme inhibitor, angiotensin receptor blocker