Abstract Body (Do not enter title and authors here): Background
Numerous studies evaluating the effects of consumption of omega-3 fatty acids (ω3FAs) and omega-6 fatty acids (ω6FAs) on the prevention of cardiovascular disease (CVD) have yielded inconsistent results. In addition, the association between ω3FAs/ω6FAs and CVD has been suggested to vary with the daily intake levels of fatty acids among individuals. On the other hand, the longitudinal associations between plasma ω3FAs/ω6FAs and arterial stiffness, which is a predictor of CVD, have not been well elucidated.
Hypothesis
We hypothesized that plasma ω3FAs are associated with the suppression of age-related increases in arterial stiffness, whereas plasma ω6FAs are associated with an increase in arterial stiffness.
Aims
The objective of this study is to fill the existing research gap by investigating the longitudinal association between plasma ω3FAs/ω6FAs and arterial stiffness in a Japanese people, known for their higher intake of marine products.
Methods
This prospective observational study included 2520 healthy Japanese participants (mean age:43.1±8.7y, men:83.1%) who underwent repeated annual health check-ups from 2008 to 2013. Participants with a history of CVD or treatment for CVD risk factors were excluded. Arterial stiffness was evaluated by brachial-ankle pulse wave velocity (baPWV), and plasma ω3FAs [docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA)]/ω6FAs [arachidonic acid (AA), dihomo-gamma-linolenic acid (DGLA)] were evaluated by gas chromatography. The longitudinal association between plasma ω3FAs/ω6FAs and baPWV was evaluated by a linear mixed model adjusted for conventional CVD risk factors.
Results
During a median follow-up of 5 years (IQR 4-5 years), 11034 baPWV measurements were performed. The linear mix model adjusted for conventional CVD risk factors revealed that both higher plasma AA and DGLA levels were significantly associated with an increase in baPWV (1SD increase in AA; β=12±3, 1SD increase in DGLA; β=14±3, both P<0.001). However, neither plasma EPA nor DHA levels were longitudinally associated with the baPWV.
Conclusion
Plasma ω3FAs were not longitudinally associated with arterial stiffness. In contrast, higher plasma ω6FAs levels were longitudinally associated with increased arterial stiffness. Our results suggest that the potential CVD-preventive effects of ω3FAs may not involve the suppression of arterial stiffness. Conversely, the increased CVD risk associated with ω6FAs may be attributed to increased arterial stiffness.