Randomized controlled trial comparing the efficacy of daily and every other day atorvastatin therapy and its correlation with serum hydroxymethylglutaryl-CoA reductase enzyme levels in naïve dyslipidemic patients

Objective: Data regarding efficacy comparison of daily regimen (DR) versus every other day regimen (EODR) atorvastatin therapy is not validated by estimation of serum hydroxymethylglutaryl-CoA reductase (HMGCR) levels and HMGCR correlation with lipid indices. Methods: In this randomized controlled trial, we compared the efficacy of DR versus EODR by measuring lipid indices and serum HMGCR levels at baseline and after 12 weeks of 10 mg atorvastatin therapy. Primary endpoint was comparison of mean change in serum HMGCR levels and lipid indices of both groups and their correlation with each other. Secondary endpoints were assessed by estimating serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and creatine kinase MM (CK-MM) levels and adverse drug reactions (ADRs). Results: A total of 61 patients were enrolled of which 46 completed the study (24 in DR vs 22 in EODR group). The mean reduction in total cholesterol (TC), low density lipoprotein-cholesterol (LDL-C) and non-high density lipoprotein-cholesterol (HDL-C) was significantly higher in DR group, whereas mean reduction in triglycerides (TG) and increase in HDL-C was similar in both the groups. Reduction in serum HMGCR levels was comparable in both the groups (31.17% vs 28.19%). Change in serum HMGCR levels correlated more with change in lipid indices of DR group. Also, safety parameters were similar between the two groups. Conclusion: Both the regimens achieved therapeutic goals, however DR was found to be superior as it achieved greater reduction in TC and LDL-C. Further, these findings are substantiated by correlation of lipid indices with serum HMGCR levels. Keywords: Atorvastatin, Every other day atorvastatin, Dyslipidemia, Hydroxymethylglutaryl-CoA reductase enzym