Fatty acids as determinants of in-vivo lipid peroxidation: The EFFGE study in Eastern Finnish hypertensive and non-hypertensive subjects

Abstract

Background. The degree of fatty acid (FA) unsaturation as a determinant of lipid peroxidation has been inadequately studied.

Methods. We examined associations of plasma free F_2α-isoprostanes (F₂-IsoPs), an indicator of in-vivo lipid peroxidation, with the levels/intake of FAs, adjusted for the risk factors of cardiovascular disease (CVD) in 1211 Finnish men and women, of whom 50% were hypertensive, aged 59.3 ± 8.3 years, mean ± SD.

Results. Elevated age- and sex-adjusted plasma free levels of omega-6 and omega-3 polyunsaturated Fas (PUFAs), saturated FAs (SFAs), and the PUFA/SFA and the omega-6/omega-3 PUFA ratios were all associated with decreased F₂-IsoPs. High dietary SFA intake was associated with elevated F₂-IsoP concentrations. In a multivariable regression (with clinical, nutritional, and behavioral CVD risk factors), female gender, body mass index (BMI), serum apolipoprotein A1, and NT-proBNP (natriuretic peptide) were positively associated with the F₂-IsoPs, whereas the dietary PUFA/SFA ratio, plasma β-carotene, the omega-6/omega-3 PUFA ratio, and protein intake showed inverse associations.

Conclusions. We propose that elevated lipid peroxidation is associated with several risk factors of CVD, such as a low PUFA/SFA ratio, whereas the FA precursors of lipid peroxidation, i.e. omega-3 and omega-6 PUFAs are associated with attenuated F₂-IsoP levels. These findings provide mechanistic support for earlier observations linking PUFA to improved cardiovascular health.

Key words::

• Cardiovascular disease
• degenerative disease
• F₂-isoprostanes
• free radicals
• hypertension
• lipid peroxidation in vivo
• metabolic diseases
• oxidative stress
• type 2 diabetes

Acknowledgements

We thank Professor Olli T. Raitakari (University of Turku) for his support during the manuscript writing. We also thank the late Professor Jason D. Morrow (Vanderbilt University) for his kindness and guidance during the set-up of GC/MS-based F₂-IsoP analytics in our laboratory at Oy Jurilab Ltd in Kuopio, Finland.

Declaration of interest: The authors declare that there is no conflict of interest.

This study was supported by the Finnish Funding Agency for Technology and Innovation (Tekes) to Oy Jurilab Ltd and MAS-Metabolic Analytical Services Oy (J.T.S.) and by the Yrjö Jahnsson foundation (J.E.K.).