Altered Serum n-6 Polyunsaturated Fatty Acid Profile and Risks of Mortality and Cardiovascular Events in a Cohort of Hemodialysis Patients

Objective: Alterations in the balance between serum n-3 and n-6 polyunsaturated fatty acids (PUFAs) is predictive of cardiovascular events among hemodialysis patients, although little is known about the serum ratio of n-6 arachidonic acid (AA) to n-6 dihomo-gamma-linoleic acid (DGLA) in renal failure. We hypothesized that AA/DGLA ratio is altered in hemodialysis patients resulting in poor clinical outcomes. Methods: This was a single center cohort study in an urban area in Japan with cross-sectional analyses. Subjects were 517 hemodialysis patients and 122 control subjects. The main exposure was serum AA/DGLA ratio, and the main outcome measures were all-cause mortality and cardiovascular events during 5 years. Results: The hemodialysis patients showed a higher median (interquartile range) AA/DGLA ratio than the control subjects (6.46 [5.22-7.81] versus 4.56 [3.74-6.34], P < .001). In a Cox proportional hazard model adjusted for age, sex, dialysis duration, diabetic nephropathy, prior cardiovascular disease, and the ratio of serum n-3 polyunsaturated fatty acids (eicosapentaenoic acid plus docosahexaenoic acid) to AA, the higher quartiles of AA/DGLA ratio were associated with higher risk for all-cause mortality with hazard ratios (95% confidence interval) of 1.50 (0.84-2.76) for quartile 2, 2.10 (1.18-3.86) for quartile 3, and 2.02 (1.10-3.78) for quartile 4 compared with quartile 1. AA/DGLA ratio showed a similar association with the risk of cardiovascular events. Conclusions: AA/DGLA ratio was elevated in patients with end-stage renal disease requiring hemodialysis, and a high AA/DGLA ratio was an independent predictor of poor clinical outcomes in this population. (C) 2017 by the National Kidney Foundation, Inc. All rights reserved.