ACE gene polymorphism and antihypertensive efficacy of losartan in patients with primary hypertension

Background The insertion/deletion (I/D) ACE gene polymorphism seems the most widely studied sequence variant of human genome. Although evidence implicates the linkage of ACE locus and the risk for arterial hypertension, there are confounding data regarding association of ACE gene polymorphism with blood pressure (BP) response to antihypertensive therapy in patients with essential hypertension. Therefore the aim of our study was to evaluate the association between I/D ACE polymorphism and antihypertensive efficacy of an angiotensin II receptor blocker — losartan. Material and methods Fifty patients (mean age 47 ± 8 years) with essential hypertension (stage I–II , ESH/ESC, 2007) were included into the study. The patients were treated with losartan starting from dose of 50 mg once daily. The dose could be increased up to 100 mg once daily if there was no normalization of blood pressure after 4 weeks of treatment. The ambulatory BP measurements (ABPM), clinic BP measurements as well as evaluation of plasma renin activity and serum angiotensin II concentration measurements were performed before and after 8 weeks of treatment. The ACE genotypes were identified by PCR method. Results The frequency distribution of ACE genotypes were as follows: 20% II homozygotes, 50% ID heterozygotes and 30% DD homozygotes. There were no significant differences in clinic characteristics and baseline BP levels among II, ID or DD patients. After 8 weeks of treatment significant decrease of BP levels both in clinic measurements and ABPM was noted regardless of ACE genotype. Losartan dose was titrated in 7 patients with II genotype (70%), 12 patients with ID genotype (48%) and in 4 patients with DD genotype (27%). Patients with DD genotype were characterized by lower systolic and diastolic BP levels after 8 weeks of treatment as compared with carriers of the I allele (ID or II). Conclusions Our results suggest the association between I/D ACE gene polymorphism and the hypotensive effect of losartan. key words: pharmacogenetics, arterial hypertension, losartan, ACE polymorphism Arterial Hypertension 2007, vol. 11, no 6, pages 498–504.