SERUM OMEGA-3 FATTY ACID LEVELS IN A LARGE INCIDENT U.S. HEMODIALYSIS POPULATION

Abstract

Long chain omega-3 (n-3 PUFA) fatty acids may influence clinical outcomes in hemodialysis patients. We therefore performed the largest characterization to date of n-3 PUFA levels in an incident hemodialysis population. Serum n-3 PUFA were measured in samples obtained at baseline in a 400 person subgroup of the ArMORR study, a large representative cohort of U.S. incident hemodialysis patients. n-3 PUFA were measured by gas chromatography, with phospholipid (PL) and triglyceride (TG) fatty acids being separated by solid phase extraction. Signed rank test was used to compare PL and TG fractions. Mean (±SD) age was 66±14 years and body mass index 26±7 kg/m2. 58% were men and 68% white. Cause of ESRD was diabetes and hypertension in 47% and 40% of subjects, respectively. Total serum 20:5n-3 (EPA) (by mean weight %) was 0.09±0.36 (PL vs. TG: 0.09±0.43 vs. 0.07±0.30, p=0.14), and total serum 22:6n-3 (DHA) was 1.46±0.72 (PL vs. TG: 3.03±1.24 vs. 0.21±0.40, p<0.001). Minimal 22:5n-3 (DPA) was detected. Total long chain n-3 PUFA levels were 1.55±0.95 (PL vs TG: 3.13±1.47 vs. 0.28±0.64, p<0.001). In summary, n-3 PUFA levels in this large U.S. cohort are low relative to published reports of levels in the general population or even in hemodialysis patients outside the U.S., making this a potential target for intervention.1 In addition, future enquiries into n-3 PUFA in hemodialysis cohorts should focus on the phospholipid fraction since we have demonstrated that, similar to the general population, this is where they primarily accumulate.