Polyunsaturated fatty acid (PUFA) dietary intake, status and serum key fatty acid (FA) ratios may aid in cardiovascular disease-related risk assessment. The aim of this study was to investigate the effects of lipid-lowering diet on key FA ratios in serum phospholipids and omega-3 index in erythrocyte phospholipids in moderately hyperlipidemic subjects. The study included 41 subjects, mean age 56±6 years. Nutritional habits were evaluated by food frequency questionnaire. Participants followed lipid lowering diet for 12 weeks. Energy intake of omega-6 and omega-3 FA was changed from 7.6% and 0.6% to 5.7% and 1.2%, respectively. Marked decrease in four FA ratios in serum phospholipids, i.e., omega-6/omega-3, arachidonic acid (AA)/eicosapentaenoic acid (EPA), AA/docosahexaenoic acid (DHA), AA/(EPA+DHA) and omega-3 index (EPA+DHA) was found in study subjects after lipid-lowering diet. Total cholesterol/high-density lipoprotein (HDL), low-density lipoprotein (LDL)/HDL and triacylglycerol/HDL-cholesterol ratios positively correlated with all FA ratios, and negatively correlated with total omega-3 levels in serum phospholipids and omega-3 index in erythrocytes. Total serum omega-3 levels showed strongest association with lipoprotein ratios and positive correlation with homeostatic model assessment (HOMA) index. In conclusion, lipid-lowering diet resulted in decreased serum key FA ratios, increased omega-3 levels, and improved insulin sensitivity that may lead to a lower risk of cardiovascular disease in subjects with moderate hyperlipidemia.
Keywords: Fatty acid ratio; Hyperlipidemia; Lipid-lowering diet; Omega 3-index; TG/HDL.