(P26-044-25) Associations of Serum Omega-6 Polyunsaturated Fatty Acids With Biomarkers of Inflammation

Objectives: Observational evidence supports associations between higher intakes of omega-6 (n-6) polyunsaturated fatty acids (PUFA) and reduced risks for cardiometabolic diseases. However, some have hypothesized that higher n-6 PUFA intake may be pro-inflammatory. It is known that serum levels of total n-6 PUFA and linoleic acid (LA), the predominant dietary n-6 PUFA, correlate with dietary LA intake. The purpose of this cross-sectional analysis using baseline data from the Aegis cohort was to examine associations of serum LA and total n-6 PUFA levels with biomarkers of inflammation.

Methods: Serum levels of high-sensitivity C-reactive protein (hs-CRP), glycoprotein acetyls, and serum amyloid A (SAA) were assessed as biomarkers of inflammation. Univariate Pearson or Spearman correlation coefficients were calculated, and multivariate linear models were used to assess biomarker levels across quintile categories of serum fatty acids (FA) with body mass index (BMI), age, and sex as covariates.

Results: Analyses included 1894 participants for whom relevant biomarker data were available (65% female, mean age: 50 y, mean BMI: 29.0 kg/m², 62% Non-Hispanic White, 11% Black/African American, 7% Hispanic/Latino, 10% Asian, 10% mixed/other). LA and n-6 PUFA levels, expressed as % of circulating FA, were inversely correlated (all P < 0.001) with hs-CRP (r = -0.19 and -0.25, respectively), glycoprotein acetyls (r = -0.24 and -0.45, respectively), and SAA (r = -0.15 and -0.16, respectively). The 20^th and 80^th percentiles for LA were 31.3% and 36.4%, respectively, and for total n-6 PUFA were 38.5% and 42.8%, respectively. Least squares geometric means (95% CI) for quintile (Q)1 and Q5 of serum LA for hs-CRP were 2.4 (2.2, 2.8) and 1.7 (1.5, 2.0) mg/L, respectively, and for glycoprotein acetyls were 0.94 (0.92, 0.95) and 0.88 (0.87, 0.90) mmol/L, respectively (both P < 0.001 for trend across quintile categories). Results were similar for total n-6 PUFA. For SAA, no significant trends across quintile categories of LA or total n-6 PUFA were present.

Conclusions: Higher serum levels of LA and total n-6 PUFA were associated with lower concentrations of hs-CRP and glycoprotein acetyls. These findings do not support the hypothesis that dietary LA is pro-inflammatory.

Funding Sources: The Indiana University Foundation funded this research.