Objectives: We investigated the changes in cholesterol absorption and synthesis markers before and after simvastatin therapy in Chinese patients with coronary heart disease. Design and method: We developed a gas chromatography method to identify cholesterol synthesis and absorption markers and measured them in patients with coronary heart disease. We then tested their use in predicting the efficacy of simvastatin in lowering cholesterol. Serum samples from 45 patients and 38 healthy humans (controls) were analyzed in a gas chromatography-flame ionization detector. Results: Squalene and five non-cholesterol sterols-desmosterol and lathosterol (synthesis markers) and campesterol, stigmasterol, and sitosterol (absorption markers)-were detected. The recovery rates of the markers were 95-102%. After simvastatin treatment for four weeks, the total cholesterol and low-density lipoprotein cholesterol levels had significantly decreased from the baseline values (p < 0.05). The baseline lathosterol level was significantly higher in good responders than in poor responders (p < 0.05), and the stigmasterol level was significantly lower in good responders than in poor responders (p <0.05). Conclusions: This method should be suitable for the detection of serum squalene and non-cholesterol markers and can be used to predict the efficacy of simvastatin in patients with coronary heart disease. (C) 2013 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.