The effect of eicosapentaenoic acid on renal function and volume in patients with ADPKD.

BACKGROUND Soy protein ameliorates rat polycystic kidney disease with concomitant renal enrichment of omega3-polyunsaturated fatty acids. A study was conducted to examine the effects of eicosapentaenoic acids (EPA) on renal volume and function in patients with autosomal dominant polycystic kidney disease (ADPKD). METHODS Non-azotemic patients were randomized to either a control group (n = 20) or an EPA group (n = 21). EPA capsules (2.4 g/day) were administered in the EPA group for 2 years. Twenty-four hours of urine was collected for the creatinine clearance (Ccr) measurement every year. At baseline and 24 months, fatty acid compositions in erythrocytes were measured and computerized tomographies were obtained for calculation of renal volume by the modified ellipsoid and volumetric methods. RESULTS In the EPA group, the EPA concentration (1.80 +/- 0.99 versus 4.40 +/- 1.79 area%, P < 0.001) and the omega3/omega6 ratio in the erythrocyte increased, but docosahexaenoic acid (DHA) (6.76 +/- 1.19 versus 5.64 +/- 1.45 area%, P < 0.010) concentration decreased. Ccr decreased by 8.5 +/- 9.5 and 9.0 +/- 13.0 ml/min/1.73 m(2)/2 years in the control and EPA groups, respectively (NS). The increases in renal volume calculated by either method were not significantly different between the two groups. CONCLUSIONS A beneficial effect of EPA on renal function and kidney volume in ADPKD patients could not be confirmed in the present study. Administration of EPA with DHA supplementation and/or longer intervention might be necessary to demonstrate preventive effects of omega3-polyunsaturated fatty acids on progression of ADPKD.