Fish oil supplementation, genetic susceptibility and risk of new-onset hypertension.

Objectives: The risk of new-onset hypertension is influenced by habitual fish oil supplementation, but whether the association is modified by genetic predisposition is unknown.

Methods: A total of 213,604 participants without hypertension were identified at baseline from the UK Biobank between 2006 and 2010. The weighted polygenetic risk score (PRS) comprising 118 identified single-nucleotide polymorphisms (SNPs) was used to quantify genetic susceptibility. Cox regression models were applied to determine the association between fish oil supplementation, PRS, and hypertension and evaluate the effect modification of genetic susceptibility.

Results: During a median follow-up of 13.8 years, 18,498 new-onset hypertension cases were identified. Approximately 30.6 % (65,452) of participants were habitual fish oil users. The hazard ratio (HR) of habitual fish oil users for hypertension was 0.94 (95 % confidence interval [CI], 0.91-0.98). Fish oil nonusers with a high genetic risk had an increased risk of hypertension (HR, 1.52; 95 % CI, 1.41-1.64) compared to fish oil users with a low genetic risk. In addition, an interaction on the additive scale between the fish oil use and intermediate or high levels of genetic susceptibility was observed. The interactive effects accounted for approximately 7 % and 22 % of the risk of developing hypertension, respectively.

Conclusions: This cohort study indicates regular fish oil supplementation could be beneficial in preventing hypertension, particularly among individuals with intermediate or high genetic susceptibility on an additive scale.