Oral fish oil supplementation raises blood omega-3 levels and lowers C-reactive protein in haemodialysis patients - A pilot study

Background. We previously reported that haemodialysis patients have suboptimal blood levels of the cardioprotective omega-3 polyunsaturated fatty acids (n-3 PUFA) eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids. In the present pilot study, we tested the hypothesis that supplementing haemodialysis patients for 12 weeks with the American Heart Association (AHA)-recommended fish oil dose would be well tolerated and efficacious in boosting blood n-3 PUFA levels and improving cardiovascular risk biomarkers. Methods. Twenty-seven subjects were randomized in a 2:1 ratio to either 1.3 g of EPA + DHA daily or placebo. Results. At baseline, 83% of subjects consumed inadequate dietary fish and had the following erythrocyte n-3 PUFA levels (mean ± SD,% weight) - EPA: 0.3 ± 0.2, DHA: 2.9 ± 2.0, and ratio of n-6/n-3 PUFA: 4.2 ± 1.3. Supplementation induced large increases in mean blood EPA and DHA levels (% increase, P-value vs placebo group): erythrocyte - EPA: +400%, P = 0.0018, DHA: +205%, P < 0.0001; plasma - EPA: +275%, P = 0.0003, DHA: +69%, P = 0.0352. Levels in the placebo group remained relatively unchanged. The omega-3 index, a value correlating with the level of cardioprotection, increased significantly in the fish oil group. A reduction in mean C-reactive protein levels (-3.3 ± 8.1 mg/l, P = 0.0282) and a trend towards lower triglyceride levels (-24 ± 74 mg/dl, P = 0.0783) were also observed in the active vs placebo group. Minimal side effects were noted. Conclusions. Our preliminary observations that the AHA-recommended fish oil dose is well tolerated, efficacious and may improve surrogate markers of cardiovascular disease in haemodialysis patients paves the way for larger clinical trials to confirm a clinical benefit.