Association of plasma polyunsaturated fatty acids with arterial blood pressure: A Mendelian randomization study

High polyunsaturated fatty acids (PUFAs) intake is recommended for primary and secondary prevention of cardiovascular disease (CVD). However, the association of PUFAs with blood pressure (BP) is still controversial. In the present study, two-sample Mendelian randomization (MR) analysis was performed to investigate the causal relationship of PUFAs with BP, including systolic blood pressure (SBP), diastolic blood pressure (DBP), and pulse pressure (PP).Genetic instruments and summary statistics for two-sample MR analysis were obtained from 3 large-scale genome-wide association studies (GWASs). Eight single nucleotide polymorphisms (SNPs) significantly (P < 5 × 10-8) related to 6 PUFAs were used as instrumental variables. Conventional inverse-variance weighted method was adopted to evaluate the causality of PUFAs with BP; the Weighted Median, MR-egger, and Leave-one-out method were used for sensitivity analyses.As a result, there was no evidence of a causal association between all PUFAs and SBP. In addition, arachidonic acid (AA, β = -0.04, P < .001) and eicosapentaenoic acid (EPA, β = -0.47, P = .02) were negatively associated with DBP, while linoleic acid (LA, β = 0.03, P = .005) and α-linolenic acid (ALA, β = 3.83, P < .001) were positively associated with DBP. There was no evidence of a causal relationship between either docosapentaenoic acid (DPA) or docosahexaenoic acid (DHA) with DBP.In conclusion, a genetic predisposition to plasma polyunsaturated fatty acid (PUFA) had a divergent effect on DBP, independent of SBP. It suggested that it is helpful for lower DBP level to supplemental intake of AA and EPA or promote the conversion of LA and ALA to AA and EPA respectively, which need to be further validated with randomized controlled studies.