The effect of n-3 fatty acids on C-reactive protein levels in patients with chronic renal failure.

BACKGROUND: Cardiovascular disease (CVD) is the leading cause of mortality in patients with chronic renal failure (CRF). C-reactive protein (CRP), a strong independent risk marker of CVD, is elevated in a large proportion of patients with CRF. The long-chain n-3 polyunsaturated fatty acids (PUFA) have cardioprotective effects, which may be partly attributed to their anti-inflammatory properties. OBJECTIVE: The study objective was to investigate the effect of n-3 PUFA on serum levels of CRP in patients with CRF. DESIGN: We performed a randomized, double-blind, placebo-controlled study. SETTING: The study took place at an outpatients clinic at the Department of Nephrology, Aalborg Hospital, Denmark. PATIENTS: The study comprised 46 patients (30 men and 16 women; mean age 59 +/- 11 years) with a serum creatinine level in the range of 150 to 400 micromol/L. INTERVENTION: The patients were randomly assigned to daily supplementation with 2.4 g n-3 PUFA or identical capsules containing 2.4 g of olive oil (control) for 8 weeks. MAIN OUTCOME MEASURE: CRP was measured with a high-sensitivity C-reactive protein (hs-CRP) assay and the content of n-3 PUFA in granulocyte membranes before and after supplementation. RESULTS: The n-3 PUFA concentration increased in granulocytes after the n-3 PUFA supplements but was unaltered by the control oil. A nonsignificant reduction in hs-CRP was observed in the n-3 PUFA group after supplementation (2.46 vs. 1.47 mg/L; P = .06), and hs-CRP was unaltered by the control oil (3.27 vs. 3.14 mg/L; P = .12). There was no difference in median hs-CRP change in the two groups. CONCLUSION: A trend was seen toward a reduction in hs-CRP in the n-3 PUFA group, but there was no significant difference in hs-CRP levels when both groups were compared.