Abstract
OBJECTIVES: Adjuvant therapy is often used to optimize the antihyperlipidemic effect of simvastatin. Omega-3 and vitamin D supplementation are recommended as adjuvant therapies to low-intensity statins. This study aimed to compare the effects of vitamin D and omega-3 as adjuvant therapy to simvastatin to improve the lipid profiles and atherogenic index of plasma (AIP) in type-I dyslipidemic rats. MATERIALS AND METHODS: Thirty-six male rats were randomized and divided into six groups: healthy control, dyslipidemic rats with no treatment, and dyslipidemic rats treated with either low-dose simvastatin only or omega-3 or vitamin D at low and high doses. Dyslipidemia was induced with high-fat diets for four weeks, followed by treatment for the next two weeks. Blood samples were withdrawn before and after simvastatin treatment. In addition, aspartate transaminase (AST) and alanine transaminase (ALT) levels were analyzed to assess liver function. RESULTS: Administration of a high-fat diet-induced type 1 dyslipidemia and increased ALT levels (p < 0.05). Treatment with low-dose simvastatin did not significantly improve triglyceride (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDLc) or non-HDLc levels. When combined with a high-dose vitamin D, simvastatin significantly reduced TG and increased HDLc levels (p < 0.05), thereby improving AIP levels. This improvement was not observed in rats treated with omega-3 or vitamin D at a lower dose. CONCLUSION: We concluded that high-dose vitamin D as an adjuvant to simvastatin therapy was superior to omega-3 in improving TG, HDL, and AIP levels. High-dose vitamin D also improved ALT levels in type-I dyslipidemic rats. This result may be translated in clinics to reduce the risk of coronary syndrome in patients with type-I dyslipidemia.