Influence of angiotensin II type 1 receptor polymorphism on hypertension in patients with hypercholesterolemia

Essential hypertension results from the combined influence of environmental and genetic factors. The relationship between angiotensin II type 1 receptor (AT(1)) A-C(1166) polymorphism and essential hypertension is controversial. Because it is accepted that high concentration of serum cholesterol is one of risk factors of atherosclerosis, we investigated the influence of the AT(1) A-C(1166) polymorphism on hypertension in patients with hypercholesterolemia. A total of 131 hypertensive, 97 borderline, and 175 normotensive subjects were enrolled in this study. We selected hypercholesterolemic subjects on the condition that their serum concentration of total cholesterol was >220 mg/dl, and obtained 55 hypertensive, 24 borderline, and 52 normotensive subjects with hypercholesterolemia. There were no significant differences in the genotype nor allele frequency between hypertensive and normotensive subjects in the overall population. However, the presence of the C allele of the AT(1) gene has a tendency to increase the value of systolic blood pressure not only in subjects with hypercholesterolemia but also in the overall population. Furthermore, we found a significant relationship between the AT(1) polymorphism and hypertension in subjects with hypercholesterolemia; i.e., the frequency of the C allele of the AT(1) gene was significantly higher in hypertensives than in normotensives (P<0.005). These results suggested that high concentration of total cholesterol was an important risk factor to the occurrence of essential hypertension for patients who carried the C allele of the AT(1) gene.