Hana M. Gashlan, Ayat M. Shourbaji

Abstract

Background: Erythrocytes are always exposed to oxidative stress, affecting their membrane lipid composition and function. Impaired fatty acids (FAs) composition of erythrocyte membrane were observed in numerous physiological and chronic diseases. Objective: The aim of the current investigation was to find out the changes in the composition of saturated, monounsaturated and polyunsaturated fatty acids in both plasma and erythrocyte membrane in hyperlipidemia patients. Material and Method: One hundred subjects were enrolled to the study. They were divided into: healthy control group (n= 30), newly diagnosed hyperlipidemia group, ND, (n=33) and treated hyperlipidemia group, TH, (n=37). RBC membrane FAs were separated, identified and were analyzed using gas-chromatography. Results: Significant elevation in almost all detected FAs in RBC membrane were registered. Palmitic and stearic acids were the main contributors in saturated fatty acids (SFAs), while Oleic and elaidic acids were the major components of mono-unsaturated fatty acids (MUFAs). From the main contributors to polyunsaturated fatty acids (PUFAs) were linoleic and arachidonic. Levels of MUFAs were higher in ND hyperlipidemia compared to healthy subjects. Same trend was also noted in TH patients compared to control volunteers. Results also demonstrated elevated percent of SFAs and MUFAs and decreased PUFAs percent, from total fatty acids, in hyperlipidemia groups. From total fatty acids the percent of either SFAs or MUFAs was greater than percent of PUFAs. PUFAs n-6 series were elevated in RBC membrane, while n-3 series showed remarkable decreased values in RBC membrane of some patients in ND and TH groups. Decreased saturation index was also obtained in ND and TH patients compared to control subjects. Conclusion: patients with hyperlipidemia, either ND or TH, had marked elevation in almost all FAs in plasma and RBC membrane. The percentage of SFAs and MUFAs from total FAs were increased while the percentage of PUFAs was decreased in hyperlipidemia. Increased dietary SFAs might lead to elevated membrane SFAs which in turn will lead to higher levels of MUFAs in ND and TH patients. Saturation index of RBC membrane, which is an indication of membrane fluidity, was decreased in patients’ group compared to control. Increased dietary intake and alterations in the metabolism of FAs may be responsible for the observed changes.