OBJECTIVE: Our purpose was to determine if over-the-counter fish oil improves the cardiovascular-disease risk profile of endstage renal disease patients.

DESIGN: This study used a double-blind, permuted-block, randomized, placebo-controlled design. The experimental intervention consisted of fish-oil concentrate supplementation, whereas corn-oil capsules were used as a control. Compliance follow-ups were performed 3 times per week.

SETTING: Patients of Central Texas Nephrology Associates clinics were eligible for this study.

PATIENTS: Exclusion criteria comprised a life-expectancy of less than 6 months, pregnancy, a history of hemodialysis or medication noncompliance, or age below 18 years. The final sample size was 87 patients. The attrition rate was 9%.

INTERVENTION: Participants in the experimental group consumed six 1-g soft-gel capsules of fish-oil concentrate each day for 6 months. The control group consumed corn-oil capsules, following the same protocol. Venous blood samples were acquired before and after the intervention.

MAIN OUTCOME MEASURE: We assessed a number of serum lipid indicators.

RESULTS: There were significant supplement/time interactions in low-density lipoprotein cholesterol (LDL) levels (P = .0001) and LDL particle number (P = .0001). Repeated-measures analysis of variance revealed significant time trends in high-density lipoprotein cholesterol (P = .012) and LDL (P = .001). High-density lipoprotein cholesterol levels significantly decreased in the control group, and increased in the fish-oil group, at 6 months, and LDL levels increased significantly in both groups.

CONCLUSIONS: The analysis indicates mixed results with respect to cardiovascular disease risk. Further research is needed to assess the benefits of an over-the-counter fish-oil supplement in the renal population.