Essential phospholipids for nonalcoholic fatty liver disease associated with metabolic syndrome: A systematic review and network meta-analysis

BACKGROUND: Essential phospholipids (EPL) are used for the supportive treatment of non-alcoholic fatty liver disease (NAFLD), but data are mostly from small-scale studies. AIM: To evaluate the efficacy of EPL treatment in adult patients with NAFLD and type 2 diabetes and/or obesity. METHODS: The MEDLINE, PubMed, Embase, and Cochrane databases were searched up to March 2019 for clinical trials and comparative observational studies. Eligible studies were those published in English or Chinese that enrolled adult patients (≥ 18 years) with NAFLD and type 2 diabetes mellitus and/or obesity receiving EPL as monotherapy or as add-on therapy to existing therapy, and that included at least one of the efficacy outcomes of interest. A variety of studies were identified; thus, direct, indirect and cohort meta-analyses were performed. Mean difference (MD) and 95% confidence interval (CI) were calculated for continuous variables, and relative risk with 95%CI for disease response and recovery. A random-effects model was used to address between-study heterogeneity. RESULTS: Ten studies met the inclusion criteria (n = 22-324). EPL treatment duration ranged from 4 to 72 wk. In the direct meta-analysis (four randomized controlled trials), compared with antidiabetic therapy alone, EPL plus antidiabetic therapy was associated with a significantly greater reduction in [alanine aminotransferase (ALT); MD: 11.28 U/L (95%CI: -17.33, -5.23), P = 0.0003], triglyceride [MD: -49.33 mg/dL (95%CI: -66.43, -32.23), P < 0.0001] and total cholesterol levels [MD: -29.74 mg/dL (95%CI: -38.02, -21.45), P < 0.0001]. There was also a significant increase in the rate of overall improvement [relative risk 1.50 (95%CI: 1.26-1.79), P < 0.0001], and risk of no disease (P = 0.0091), and a reduction in moderate disease (P = 0.0187); there were no significant differences in severe disease, mild disease, or significant improvement. In the cohort meta-analysis of three non-randomized clinical trials, the MD in ALT levels was -16.71 U/L (95%CI: -24.94, -8.49) and 23% of patients had improved disease. In the cohort meta-analysis of five randomized trials, MD in ALT levels was –28.53 U/L (95%CI: -35.42, -21.65), and 87% (95%CI: 81%, 93%) and 58% (95%CI: 46%, 70%) of patients showed clinical improvement and significant clinical improvement. CONCLUSION: This analysis provides evidence for a benefit of EPL in patients with NAFLD and diabetes and/or obesity. Further large-scale trials are warranted.