Relationship Between Serum ω-3 Polyunsaturated Fatty Acid Concentration and Fatty Acid Fraction of Epicardial Adipose Tissue in Patients With Cardiovascular Disease

Background: ω-3 polyunsaturated fatty acids (PUFAs), such as eicosapentaenoic acid (EPA, C20:5ω3) and docosahexaenoic acid (DHA, C22:6ω3), are widely regarded as cardioprotective. EPA, but not DHA, has been reported to prevent fibrosis in heart failure. The relationship between the ω-3 PUFA fraction in epicardial adipose tissue (EAT) and subcutaneous adipose tissue (SAT) and vascular inflammation in patients with cardiovascular disease remains unclear.

Methods: EAT was collected from patients undergoing cardiovascular surgery (n=21, 11 men, 10 women, 70.4±9.0 years old). Fatty acid fractions were measured in serum, SAT, and EAT by gas chromatography, and serum tumor necrosis factor (TNF) α was measured. No patient had taken EPA or DHA supplements.

Results: DHA concentrations were significantly higher in EAT than in SAT (p=0.001); EPA showed no significant difference. The EPA level of EAT correlated with the serum EPA concentration (p=0.009) but did not correlate significantly with serum DHA, α-linolenic acid (ALA, C18:3ω3), or linoleic acid (LA, C18:2ω6) concentrations. The EPA level of EAT showed a strong correlation with docosapentaenoic acid (DPA, C22:5ω3) and the DHA level of EAT (DHA: p<0.001). ALA (r=-0.519, p=0.039) and EPA (r=-0.611, p=0.027) levels of EAT correlated negatively with the serum TNFα concentration. There were no significant differences in EPA in serum, SAT, and EAT between patients with and without atherosclerotic heart disease.

Conclusions: Among ω-3 PUFA fractions in EAT, ALA and EPA were associated with anti-inflammatory effects in patients with cardiovascular disease. It is likely that an increase in serum EPA concentration is needed to increase ω-3 PUFA levels in EAT.