Adipose tissue content of ω-6 polyunsaturated fatty acids and all-cause mortality: A Danish prospective cohort study

Background: n-6 (omega-6) Polyunsaturated fatty acids may exert divergent biological effects, but limited knowledge exists about their associations with mortality. Objectives: To investigate the associations between adipose tissue content of individual n-6 polyunsaturated fatty acids-a long-term marker of endogenous exposure to these fatty acids-and all-cause mortality. Methods: We used a prospective cohort study design. We followed a random sample of 4663 participants from the Danish diet, cancer, and health cohort, which was established between 1993 and 1997. Information on all-cause mortality was retrieved from the nationwide Danish civil registration system. An adipose tissue biopsy was collected from the buttock at recruitment and analyzed for fatty acid composition using gas chromatography. Hazard ratios were obtained using Cox proportional hazard regression. Results: During a median of 21 y of follow-up, 1160 participants died. The median adipose tissue contents of linoleic acid and arachidonic acid were 10.60% and 0.36%, respectively. In multivariable continuous analyses, we observed a statistically significant inverse association between adipose tissue content of linoleic acid and all-cause mortality (P < 0.001). In contrast, a statistically nonsignificant positive association was found in continuous analyses of adipose tissue content of arachidonic acid and all-cause mortality (P 1/4 0.078). Comparing the highest with the lowest quartile, the hazard ratio for mortality was 0.76 (95% confidence interval [CI]: 0.64, 0.90) for linoleic acid and 1.28 (95% CI: 1.07, 1.53) for arachidonic acid in adipose tissue, respectively. Conclusions: Adipose tissue content of linoleic acid was inversely associated with all-cause mortality, whereas adipose tissue content of arachidonic acid was associated with a higher all-cause mortality.