Lipid Lowering Efficacy between Morning and Evening Simvastatin Treatment: A Randomized Double-Blind Study
Thipaporn Tharavanij MD*, Sirichai Wongtanakarn MD**, Nusiri Lerdvuthisopon PhD***, Sugree Teeraaunkul BPharm****, Pilasinee Youngsriphithak BPharm****, Paskorn Sritipsukho MD*****
Affiliation : * Division of Endocrinology, Department of Medicine, Faculty of Medicine, Thammasat University, Pathumthani, Thailand ** Department of Medicine, Faculty of Medicine, Thammasat University, Pathumthani, Thailand *** Preclinical department, Faculty of Medicine, Thammasat University, Pathumthani, Thailand **** Pharmacology Unit, Thammasat University Hospital, Pathumthani, Thailand ***** Postgraduate Studies Program, Faculty of Medicine, Thammasat University, Pathumthani, Thailand
Objectives: To compare lipid-lowering efficacy and high sensitive C-reactive protein (hsCRP) level between morning and
evening simvastatin administration in hyperlipidemia subjects.
Material and Method: A randomized double blind controlled trial was conducted in 52 dyslipidemia subjects. A group of
twenty five subjects received 10 mg simvastatin in the morning and placebo in the evening. The other group of twenty seven
subjects received vice versa. Serum lipid profiles were evaluated every 4 weeks for the total course of 12 weeks. High sensitive
CRP was measured at the beginning and the end of the study.
Results : Baseline LDL levels were similar in both groups (p = 0.95). The evening simvastatin group had significantly less low
density lipoprotein level (LDL) than the morning group at 4 weeks (112 + 26.1 mg/dl vs. 136.3 + 32 mg/dl, p = 0.001) and
8 weeks after treatment (109.7 + 28 mg/dl vs. 129.5 + 27 mg/dl, p = 0.006). Difference in LDL after 12th week between two
groups was not significant (p = 0.23). Triglyceride and HDL level were not different in both groups. Only evening simvastatin
administration could significantly decrease hsCRP (p = 0.03).
Conclusion : Simvastatin should be taken in the evening. Although lipid profiles were not statistically different in morning and
nighttime simvastatin, the inflammatory marker (hsCRP level) is significantly reduced as a result of evening simvastatin
administration.
Keywords : Simvastatin, Lipid, Efficacy, Morning, Evening
