FISH-OIL IN DIABETIC NEPHROPATHY

OBJECTIVE - Recent studies in nondiabetic kidney diseases suggest that dietary supplementation with n-3 polyunsaturated fatty acids (fish oi l) may have beneficial effects on albuminuria, kidney function, arteri al blood pressure, and dyslipidemia. Therefore, we evaluated the long- term effect of fish oil in diabetic nephropathy. RESEARCH DESIGN END M ETHODS - A 1-year double-blind randomized controlled study comparing f ish oil (4.6 g n-3 fatty acids/day) with placebo (olive oil) was perfo rmed in an outpatient clinic in a tertiary referral center. Thirty-six normotensive IDDM patients with diabetic nephropathy were included; 1 8 were treated with fish oil. Seven patients dropped out (four receive d fish oil), and results for the remaining 29 are presented. Albuminur ia (enzyme immunoassay), glomemlar filtration rate (Cr-51-labeled EDTA plasma clearance), 24-h ambulatory blood pressure, and lipid profile were determined every 6 months. RESULTS - Albuminuria increased by 22% (1-46%) (mean [95% CI]) in the fish oil group vs. 15% (-11-49%) in th e placebo group (NS). Glomerular filtration rate decreased from 116 +/ -7 to 105 +/- 7 ml . min(-1) 1.73 m(-2) (mean +/- SE) vs. from 108 +/- 6 to 103 +/- 7, fish oil and placebo, respectively (NS). No significa nt changes occurred in 24-h ambulatory blood pressure: from 141 +/- 4/ 82 +/- 2 mmHg to 142 +/- 5/83 +/- 2 vs. from 140 +/- 4/78 +/- 2 to 144 +/- 4/80 +/- 3, fish oil and placebo, respectively (NS). In the fish oil group, serum triglycerides (median [range]) decreased from 0.97 (0 .5-4.0) mmol/l to 0.8 (0.4-3.0) vs. from 1.01 (0.4-2.0) to 1.09 (0.4-2 .0) in the placebo group (P < 0.05) and VLDL cholesterol decreased fro m 0.45 (0.23-1.88) to 0.37 (0.21-1.43) mmol/l vs. from 0.44 (0.21-0.94 ) to 0.41 (0.17-1.94)(P < 0.05), but total and LDL cholesterol rose in the fish oil compared with the placebo group. CONCLUSIONS - Our study does not suggest that fish oil has beneficial effects on albuminuria, kidney function, blood pressure, and dyslipidemia in normotensive IDD M patients suffering from diabetic nephropathy.