Introduction & Objective: It has been shown that there is a correlation between cholesterol con-centration and coronary heart disease (CHD). Cholesteryl ester transfer protein (CETP) plays a central role in lipoproteins metabolism and it has been suggested that various polymorphisms in CETP gene can affect the enzyme activity and blood lipid parameters. There was not enough information about distribution and effects of Msp1 genotypes on lipid levels, especially in Iranian population. Therefore, we studied CETP Msp1 polymor-phism and its effects on lipid parameters in subjects with and without hypercholesterolemia.

Materials & Methods: In this experimental study, 100 subjects with hypercholesterolemia and 200 healthy individuals were selected as the study population. Lipid parameters and CETP activity were measured in serum. Determination of Msp1 genotypes was performed using polymerase chain reaction and restriction fragment length polymorphism techniques.

Results: Frequency of M1 allele in hypercholesterolemic and healthy subjects was 27% and 21.25% respectively. The frequency of M1M1 genotype was significantly high in hypercholesterolemic patients compared to healthy ones. The levels of LDL-C and TC in patients with M1M1 genotype were higher than patients with M1M2 and M2M2 genotypes. CETP activity was high in all subjects with M1M1 genotype.

Conclusion: It has been concluded that the Msp1 polymorphism of CETP probably affects lipid parameters and CETP activity.