Studies have shown that HMG-CoA reductase inhibitors (statins) play an important role in the prevention and treatment of atherosclerosis and hyperlipidemia. The aim of this study was to investigate the effect of 3-month treatment with simvastatin on serum levels of Insulin-Like Growth Factor-1 (IGF-1) in patients with diagnosed hypercholesterolemia. In total, 156 patients with hypercholesterolemia were recruited for the study. The inclusion criteria for this study were designed to allow the enrollment of a representative group of patients for cytokine studies. The patients were divided into two groups: (1) patients with a mild-to-moderate risk of heart disease, who had total cholesterol (TC) < 300 mg/dl (7.8 mmol/l), LDL-cholesterol < 210 mg/dl (5.4 mmol/l), and who lacked risk factors for coronary artery disease (CAD) after treatment with a diet for 3 months; (2) patients with a high-to-very high risk of CAD, who had TC > 300 mg/dl (7.8 mmol/l), LDL-cholesterol > 210 mg/dl (5.4 mmol/l), and at least two risk factors for CAD after treatment with a diet and administration of simvastatin (20 mg/day) for a three month period. The control group consisted of ten healthy volunteers who each had a normal lipid profile. Total cholesterol, LDL-cholesterol and IGF-1 concentrations were measured at baseline and either after six months of dietary supplementation (first group) or after three months of dietary supplementation and three months of simvastatin treatment (second group).
Conclusions: In patients with mild-to-moderate risk of CAD, a decreased serum concentration of IGF-1 was observed three months after beginning a low-fat diet. However, no changes in the serum concentration of IGF-1 were noted in patients with high-to-very high risk of CAD. Additional three-month treatment with simvastatin decreased the serum concentration of IGF-1.