Effects of simvastatin 20 mg/d on serum lipid profiles in Japanese hyperlipidemic patients: A prospective, open-label pilot study.

BACKGROUND: Hyperlipidemia is a major risk factor for ischemic heart disease. Hydroxymethylglutaryl coenzyme A reductase inhibitors ("statins") (eg, simvastatin) are considered first-line cholesterol-lowering therapy because they are effective and well tolerated, even at high doses. Based on a literature search, no studies have been published concerning the effects of simvastatin 20 mg/d in Japanese patients who had not previously received lipid-lowering treatment.
OBJECTIVE: The aim of this study was to assess the clinical tolerability and effectiveness of simvastatin 20 mg/d in achieving the target lipid concentrations recommended in the 2002 Japan Atherosclerosis Society (JAS) guidelines in Japanese patients with hyperlipidemia.
METHODS: This prospective, open-label pilot study was conducted at Kashiwa Hospital, Jikei University School of Medicine, Kashiwa, Japan. Male and postmenopausal female patients aged ≥18 to 70 years with hyperlipidemia (total cholesterol [TC], ≥220 mg/dL; triglycerides [TG], 150-400 mg/dL) who had not received lipid-lowering medications for at least 6 months before the study were enrolled. Patients received simvastatin 20 mg PO QD for 4 weeks. Effectiveness was assessed using serum concentrations of TC, low-density lipoprotein cholesterol (LDL-C), TG, and lipid peroxide, measured at 0 (baseline) and 4 weeks. Target serum TC and LDL-C concentrations as outlined by the JAS were as follows: category A, TC <240 mg/dL and LDL-C <160 mg/dL; category B1 and B2, TC <220 mg/dL and LDL-C <140 mg/dL; and category C, TC <200 mg/dL and LDL-C <120 mg/dL. A subanalysis of the correlation between baseline high-density lipoprotein cholesterol (HDL-C) and target achievement rates was conducted by baseline HDL-C concentration (<50 or ≥50 mg/dL). Tolerability was assessed using spontaneous reporting of adverse events and laboratory analysis, including liver function tests.
RESULTS: Twenty-two patients participated in the study (16 women, 6 men; mean [SD] age, 56.0 [8.0] years; mean [SD] body mass index, 23.6 [3.4] kg/m(2)). Mean serum TC, LDL-C, TG, and lipid peroxide concentrations significantly decreased from baseline (changes, -28.6%, -40.4%, -24.0%, and -14.5%, respectively; P < 0.001, <0.001, <0.001, and <0.01, respectively). The mean HDL-C concentration significantly increased from baseline (change, 7.2%; P < 0.001); the mean increase was significantly greater in patients with baseline HDL-C <50 mg/dL compared with those with baseline HDL-C ≥50 mg/dL (changes, 11.3% vs 4.4%; P < 0.05). Target TC and LDL-C concentrations were achieved in 90.9% of patients. No serious adverse events were observed, and liver enzyme and creatine kinase concentrations did not increase to above-normal values.
CONCLUSIONS: The results of this study suggest that simvastatin 20 mg/d might be useful in the clinical treatment of hyperlipidemia in Japanese patients. The study drug was well tolerated.