Effect of animal versus plant omega-3 polyunsaturated fatty acids on serum level of fetuin-A in patients with chronic renal failure; a randomized double-blinded parallel clinical trial

Abstract

Introduction: Low levels of fetuin-A in patients with chronic kidney disease (CKD) are associated with arterial stiffness, vascular calcification and cardiovascular mortality. Objectives: The aim of the present study was to investigate and compare the effect of omega-3 supplements with plant (flaxseed) and animal origins on fetuin-A levels in patients with chronic renal failure. Patients and Methods: In the present clinical trial, 90 patients with chronic renal failure (chronic kidney disease) were randomly divided into three groups. The first group received two grams of omega-3 tablets per day of animal origin (fish oil), the second group received 2 g of omega-3 tablets per day of plant origin (flaxseed oil), and the third group received one placebo per day as the control group. The duration of the drug treatment was 90 days. Before and after the intervention, blood levels of fetuin-A, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), low-density lipoprotein (LDL-C), high-density lipoprotein (HDL-C) and triglyceride (TG) were determined. Data were analyzed by SPSS statistical software. Results: Before and after the intervention, LDL-C and HDL-C levels were not significantly different in the study groups. In the animal origin omega-3 group, the levels of triglycerides and cholesterol decreased significantly after the intervention compared to before the intervention (P=0.004), however they did not change significantly in the plant origin omega-3 and control groups. Before and after the intervention, fetuin-A and ESR levels were not significantly different in the study groups. The frequency of positive CRP results in the animal and plant origin omega-3 groups was 20% and 24% respectively before intervention and 4% and 24% after intervention respectively, indicating a decrease in the levels of CRP in the animal origin omega-3 group. Conclusion: Animal origin omega-3 is more effective in reducing serum lipids and CRP than plant-origin omega-3. Omega-3 supplements of plant or animal origin have been more effective in men than in women.