Association Between Cytochrome P450 2C9 Gene Polymorphisms and Blood Pressure in Response to Losartan

Abstract

To identify the genetic contribution to the variation in blood pressure (BP) response to angiotensin receptor blockers (ARBs), single-nucleotide polymorphisms (SNPs) in the cytochrome P450 (CYP) 2C9 gene were evaluated for their association with BP response to Losartan in Pakistani patients with hypertension. We selected 100 hypertensive patients and genotyped them for CYP2C9*1, *2, and *3. Our results show that 40% of patients were responsive to antihypertensive treatment as per the defined criteria (a reduction of at least 10mm systolic & 5mm diastolic). More than 63% of patients who had wild-type CYP2C9 genotype did not respond to antihypertensive therapy, the rest did respond to the antihypertensive therapy. Similarly, more than 46% of patients having one of the polymorphic genotypes did not respond to therapy while the rest did. However, there was no statistically significant difference between the two groups and hence polymorphism in the CYP2C9 gene in our hypertensive cohort had no association with the antihypertensive therapy including Losartan. Since our study has a relatively low sample size, we encourage larger studies to replicate and confirm these findings.