Plasma Levels of Polyunsaturated Fatty Acids and Adverse Kidney Outcomes

Abstract

Rationale & Objective: Many studies have reported polyunsaturated fatty acids (PUFA) as significant predictors of cardiovascular disease, but little is known about the relationship between PUFA levels and chronic kidney disease (CKD). This study explored this relationship among individuals with and without CKD. Study Design: Prospective observational cohort study. Setting & Participants: 73,419 participants without CKD (cohort 1) and 6,735 participants with CKD (cohort 2) in the UK Biobank Study, with PUFA levels measured between 2007 and 2010. Exposure: Percentage of plasma PUFA, omega- 3 fatty acid (FA), omega-6 FA, docosahexaenoic acid (DHA), and linoleic acid relative to total FA. Outcome: Incident CKD for cohort 1 and incident kidney failure requiring replacement therapy (KFRT) for cohort 2. Analytical Approach: Cox proportional hazards regression analyses, including a cause-specific competing risk model. Results: In cohort 1, individuals with higher quartiles of plasma PUFA levels had healthier lifestyles and fewer comorbidities. During 841,007 person-years of follow-up (median 11.9 years), incident CKD occurred in 4.5% of participants (incidence rate, 39.1 per 10,000 person-years). For incident CKD in cohort 1, the adjusted cause-specific hazard ratios for quartiles 2, 3, and 4 were 0.83 (95% CI, 0.750.92), 0.85 (95% CI, 0.76-0.9 6), 0.71 (95% CI, 0.62-0.82), respectively, compared with quartile 1. This inverse relationship was consistently observed for all PUFA types. In cohort 2, although total PUFA levels were not associated with KFRT, higher PUFA subtype levels of DHA were associated with a lower risk of KFRT. Limitations: Observational design and limited generalizability to individuals with higher disease severity; no data on eicosapentaenoic acid. Conclusions: Among individuals without CKD, higher plasma PUFA levels and all 4 PUFA components were associated with a lower risk of incident CKD. In individuals with CKD, only the omega-3 component of PUFA, DHA, was associated with a lower risk of KFRT.