ANÁLISE DO POLIMORFISMO DO GENE GSTM1 EM PACIENTES COM ATEROSCLEROSE.

Abstract

The word Atherosclerosis comes from the Greek words athero that means gruel or paste and sclerosis that means hardness. The disease is characterized by lesions in the inner layer of the blood vessels called atheroma or atheromatous plaques. Those plaques block the vascular lumen and weaken the underlying tunica media. Several risk factors for the development of atherosclerosis have been described in the scientific literature. They are divided into modifiable and non-modifiable. The former includes hypertension, smoking, obesity, elevated levels of LDL cholesterol, decreased HDL levels, sedentary lifestyle and stress and the latter includes diabetes mellitus, family hypertension, thrombophilia, sex, age, genetic factors and premature family history of heart disease. The association of polymorphisms in the GST gene with coronary artery disease has been target of studies since polymorphisms may affect the enzyme activity and contribute to the onset of atherosclerosis. This present research aimed to analyze the polymorphism of GSTM1 in individuals diagnosed with atherosclerosis and in healthy individuals composing the control group. We collected peripheral blood samples from 200 patients with a previous diagnosis of atherosclerotic disease based on clinical examination and confirmed by imaging methods. The control group was composed by 100 samples. The GSTM1 polymorphism genotypes were determined by PCR. A significant difference was observed between the groups (atherosclerosis x control) regarding the GSTM1 polymorphism. The frequency of the GSTM1 present genotype in atherosclerosis group was 1.2 times higher compared to the control group. We found no significant difference between the present and null genotypes associated with variables such as gender, alcohol and smoking. However when we compared the present and null genotypes associated with smoking habits we found that the GSTM1 present was more frequent, a frequency of 52.6% in the case group for individuals who reported smoking 20 or more cigarettes per day and 60.0% in the control for individuals who smoke 10 to 20 cigarettes per day (p = 0.0035). When we analyze the variable smoking regarding years of smoking, the GSTM1 present genotype was more frequent in individuals who reported being former smokers. The frequency of the GSTM1 present genotype in the case group was 45.5% in individuals who have smoked for more than 20 years and 50.0% in the control group for those who have smoked less than 10 years and 50.0% between 10 to 20 years (p = 0.0240).