Omega-3 fatty acids therapy for IgA nephropathy: a meta-analysis of randomized controlled trials

Background: The efficacy of omega-3 fatty acids (O3FA) in IgA nephropathy remains a controversial issue. The aim of the current updated meta-analysis is to assess the efficacy of O3FA treatment for adult IgA nephropathy. Methods: We searched PubMed/MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials for randomized controlled trials that compared O3FA treatments with placebo or no treatment in adult IgA nephropathy. Outcomes of interest were effects on urine protein excretion (UPE) and renal function. Results: Five RCTs (239 patients) were included for analysis. Compared with control groups, O3FA treatments did not show significant benefits for reducing UPE (standardized mean difference (SMD), -0.111; 95% confidence interval (Cl), -0.369 -0.147) or improving glomerular filtration rate (GFR) or estimated GFR (SMD, 0.177; 95% Cl, -0.082 -0.435), although the pooled results slightly favored O3FA. On the other hand, a lower risk of an increase of 50% or more in serum creatinine and ESRD were found in O3FA-treated IgA nephropathy patients (RR 0.189; 95% Cl 0.068 - 0.524, p = 0.001; RR 0.236; 95% Cl 0.094 - 0.594, p = 0.002), but the two outcomes were reported in only two trials. Conclusion: The current meta-analysis suggests that there are insufficient data to confirm the efficacy of O3FA treatments for proteinuria and renal function in IgA nephropathy. Further large scale trials are needed to shed more light on this issue.