Causal effects of serum levels of n-3 or n-6 polyunsaturated fatty acids on coronary artery disease: Mendelian randomization study

Abstract

AbstractBackgroundAdditional studies on the causal effects of 3-n and 6-n polyunsaturated fatty acids (PUFAs) on the risk of coronary artery disease (CAD) are warranted.MethodsThis Mendelian randomization (MR) study utilized a genetic instrument developed from previous genome-wide association studies for various serum 3-n and 6-n PUFA levels. First, we calculated the allele scores for genetic predisposition of PUFAs in individuals of European ancestry in the UK Biobank data (N=337,129). The allele score-based MR was obtained by regressing the allele scores to CAD risks. Second, summary-level MR was performed with the CARDIoGRAMplusC4D data for CAD (N=184,305). The inverse variance-weighted or Wald ratio method was the main analysis for the summary-level MR, and when multiple single nucleotide polymorphisms were utilized (e.g., linoleic acid), MR-Egger and weighted median methods were implemented as sensitivity analyses.ResultsHigher genetically predicted eicosapentaenoic acid and dihomo-gamma-linolenic acid levels were significantly associated with a lower risk of CAD both in the allele-score-based and summary-level MR analyses. Higher allele scores for linoleic acid level were significantly associated with lower CAD risks, and in the summary-level MR, the causal estimates by the MR-Egger and weighted median methods also indicated that higher linoleic acid levels cause a lower risk of CAD. Arachidonic acid was the 6-n PUFA that showed significant causal estimates for a higher risk of CAD. Higher docosapentaenoic acid and adrenic acid levels showed inconsistent findings in the MR analysis results.ConclusionsThis study supports the causal effects of certain 3-n and 6-n PUFA types on the risk of CAD.