Comparing the combination therapy of ezetimibe and atorvastatin with atorvastatin monotherapy for regulating blood lipids: a systematic review and meta-analyse.

Background: Although there were many studies reporting the combination therapy of Ezetimibe and Atorvastatin's efficacy and Atorvastatin monotherapy's, the conclusions were controversial. Therefore, a systematic review and meta analysis of combination therapy and monotherapy were conducted.
Methods: PubMed, Cochrane Library and Embase were searched for studies of the combination therapy of Ezetimibe and Atorvastatin and Atorvastatin monotherapy published up to October 20, 2017. Two investigators assessed the articles for eligibility and evaluated quality.The changed values and the efficacy of low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), Total Cholesterol (TC) and Triglyceride (TG) indicators were the outcomes. Four doses of the comparisons were included: the combination therapy of Ezetimibe (10 mg) and Atorvastatin (10 mg) (E10 + A10) versus Atorvastatin (20 mg) monotherapy (A20); E10 + A10 vs. A10; E10 + A20 vs. A40; E10 + A40 vs. A80. Review manager software 5.1 was used for quality assessment and Stata version 12.0 software was used for statistical analysis.
Results: eventeen studies (11 publications) were included in the meta analysis. Compared with Atorvastatin monotherapy, the overall efficacy of combination therapy of Ezetimibe and Atorvastatin on lowering LDL-C (MD = - 15.38, 95% CI: -16.17 to - 14.60; I ²  = 26.2%, n = 17), TC (MD = - 9.51, 95% CI: -10.28 to - 8.74; I ²  = 33.7%, n = 17) and TG (MD = - 6.42, 95% CI: -7.78 to - 5.06; I ²  = 0%, n = 15) and raising HDL-C (MD = 0.95, 95% CI: 0.34 to 1.57; I ²  = 0%, n = 17) was significant. The efficacy of the comparison on HDL-C was largely significant for the different doses.
Conclusions: The overall efficacy and subgroup's efficacy of combination therapy of Ezetimibe and Atorvastatin on lowering LDL-C, TC and TG was significantly better than Atorvastatin monotherapy's. The overall and the E10 + A10/A20 group's effectiveness of combination therapy on rasing HDL-C were significantly.