Effect of fish oil supplement in maintenance hemodialysis patients: a systematic review and meta-analysis of published randomized controlled trials

The purpose of this study was to systematically assess the efficacy of fish oil therapy on maintenance hemodialysis patients (MHD). Electronic databases, including PubMed, Cochrane library, EMBase, and Web of Science, were searched for randomized controlled trials (RCTs) of fish oil versus placebo or no treatment in MHD patients. The study selection and data extraction were conducted independently by two reviewers, and statistical analysis was performed using RevMan software, version 5.2. A total of thirteen eligible RCTs involving 916 subjects (461 in the experimental group and 455 in the control group) were included. The meta-analysis showed that fish oil significantly reduced arteriovenous graft (AV-graft) events [risk ratio (RR) 0.71, 95 % confidence interval (CI) were (0.52, 0.97)] and cardiovascular events [RR (95 %CI) were 0.41 (0.26, 0.66)] in the fish oil group. In addition, compared with the control group, fish oil significantly decreased the Beck Depression Inventory (BDI) score [weighted mean difference (WMD) (95 %CI) were -11.91 (-15.88, -7.95)], serum intact parathyroidism (iPTH), C-reactive protein (CRP), and triglycerides (TG) [standard mean difference (SMD) (95 %CI) were -0.56 (-0.89, -0.23); -0.36 (-0.63, -0.09), and -0.41 (-0.68, -0.14), respectively]. However, the fish oil group did not differ significantly from the control group in albumin (ALB), hemoglobin (Hb), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-c), and mortality. Fish oil reduced the risk of AV-graft events and cardiovascular events, and alleviated depression symptoms in MHD patients. It can also improve secondary hyperparathyroidism, micro-inflammation, and hypertriglyceridemia. But there is no evidence that fish oil can improve nutritional status and renal anemia.