Higher Plasma Phospholipid n-3 PUFAs, but Lower n-6 PUFAs, Are Associated with Lower Pulse Wave Velocity among Older Adults

Background: Higher intake of polyunsaturated fatty acids (PUFAs) and higher circulating PUFAs are associated with lower cardiovascular disease (CVD) risk. The positive influence of PUFAs might be via lowering arterial stiffness, resulting in a better CVD risk profile; however, studies investigating circulating PUFAs in relation to arterial stiffness in a general population are limited. Objective: We investigated the associations of plasma phospholipid n-3 (v-3) and n-6 PUFAs and fish oil intake with arterial stiffness. Methods: We used data from a subgroup of the Age, Gene/Environment Susceptibility-Reykjavik (AGES-Reykjavik) Study (n = 501, 75.0 6 4.96 y, 46% men), a population-based study of community-dwelling older adults. Plasma phospholipid PUFAs were measured by GC at baseline, and fish oil intake was assessed at 3 time points: early life (ages 14-19 y), midlife (ages 40-50 y), and late life (ages 66-96 y, AGES-Reykjavik baseline) with the use of a validated food-frequency questionnaire. Arterial stiffness was determined as carotid-femoral pulse wave velocity (cf-PWV) with the use of an electrocardiogram after a mean follow-up of 5.2 6 0.3 y. Regression coefficients (95% CIs), adjusted for demographics, follow-up time, risk factors, cholesterol, triglycerides, and serum vitamin D, were calculated by linear regression per SD increment in PUFAs. Results: Plasma total n-3 PUFAs, eicosapentaenoic acid, and docosahexaenoic acid were associated with lower cf-PWV [b (95% CI): 20.036 (20.064, 20.008); 20.031 (20.059, 20.003); 20.036 (20.064, 20.009), respectively]. In contrast, plasma total n-6 PUFAs and linoleic acid were associated with higher cf-PWV [0.035 (0.009, 0.061) and 0.034 (0.008, 0.059)]. Regular fish oil consumption at early-, mid-, and late-life was not associated with cf-PWV. Conclusions: Our results show a positive association between plasma n-6 PUFAs and arterial stiffness, and suggest that higher concentrations of plasma long-chain n-3 PUFAs are associated with less arterial stiffness and therein may be one of the mechanisms underlying the association between plasma n-3 PUFAs and lower CVD risk.