The effect of short-term omega-3 polyunsaturated fatty acid supplementation in patients with chronic renal insufficiency

Previous studies in patients with moderate to end-stage renal insufficiency. revealed varying results of omega-3 polyunsaturated fatty acids (omega-3 PUFA) on renal function, viscosity of erythrocyte suspensions, and lipid profile. In order to further elucidate the influence of omega-3 PUFA on these variables, seven non-diabetic patients with chronic renal insufficiency ingested six capsules of fish oil (containing 1,800 mg of eicosapentaenoic acid C20:5 omega-3 and 1,200 mg of docosahexaenoic acid C22:6 omega-3) daily for 12 weeks. Measurements were performed at baseline, after 12 weeks of fish oil ingestion, and again 12 weeks after withdrawal of the supplementation. Glomerular filtration rate and effective renal plasma flow did not change in this short-term study. Erythrocyte viscosity, measured at hematocrit of 0.80 in buffer with a Contraves low shear 30 rheometer at various shear rates, improved significantly, especially at the lower shear rates. Lipid profile analysis (ultracentrifuge technique) showed a significant rise in high-density lipoprotein (HDL)2- and total HDL-cholesterol, and a decrease in very low-density lipoprotein-cholesterol and triglycerides concentration. However, low-density lipoprotein (LDL)-cholesterol rose as well and total cholesterol tended to rise. HDL2/LDL-ratio and HDL/LDL-ratio did not change. We conclude that daily addition of small amounts of omega-3 PUFA to the diet of patients with moderate to severe renal insufficiency has, in addition to a beneficial effect on erythrocyte deformability, both positive and negative effects on lipid profile. Whether the favorable effects outweigh the unfavorable effects remains to be clarified.