A CONTROLLED TRIAL OF FISH-OIL IN IGA NEPHROPATHY

Background. The n-3 fatty acids in fish oil affect eicosanoid and cyto kine production and therefore have the potential to alter renal hemody namics and inflammation. The effects of fish oil could prevent immunol ogic renal injury in patients with IgA nephropathy. Methods. In a mult icenter, placebo-controlled, randomized trial we tested the efficacy o f fish oil in patients with IgA nephropathy who had persistent protein uria. The daily dose of fish oil was 12 g; the placebo was a similar d ose of olive oil. Serum creatinine concentrations, elevated in 68 perc ent of the patients at base line, and creatinine clearance were measur ed for two years. The primary end point was an increase of 50 percent or more in the serum creatinine concentration at the end of the study. Results. Fifty-five patients were assigned to receive fish oil, and 5 1 to receive placebo. According to Kaplan-Meier estimation, 3 patients (6 percent) in the fish-oil group and 14 (33 percent) in the placebo group had increases of 50 percent or more in their serum creatinine co ncentrations during treatment (P = 0.002). The annual median changes i n the serum creatinine concentrations were 0.03 mg per deciliter (2.7 mu mol per liter) in the fish-oil group and 0.14 mg per deciliter (12. 4 mu mol per liter) in the placebo group. Proteinuria was slightly red uced and hypertension was controlled to a comparable degree in both gr oups. The cumulative percentage of patients who died or had end-stage renal disease was 40 percent in the placebo group after four years and 10 percent in the fish-oil group (P = 0.006). No patient discontinued fish-oil treatment because of adverse effects. Conclusions. In patien ts with IgA nephropathy, treatment with fish oil for two years retards the rate at which renal function is lost,