AGTR1 variant rs2638355 is associated with increased salt sensitivity of blood pressure: a female-specific effect in individuals from the HyperPath cohort.

Abstract

Salt-sensitive hypertension (SSH) affects approximately half of the hypertensive population, increasing the risk of vascular complications. The underlying pathophysiological mechanisms of SSH remain complex and need to be fully elucidated. Our prior research has identified genetic factors contributing to the salt sensitivity of blood pressure (SSBP), particularly involving genes regulating volume and blood pressure. We also observed enhanced peripheral vascular response to angiotensin II in humans with salt-sensitive hypertension. Given the pivotal role of the angiotensin II receptor type-1 (AT1R or AGTR1) in blood pressure and intravascular volume regulation, we hypothesized a genetic association between AGTR1 and SSBP. Our study involved 240 individuals of European ancestry from the HyperPATH cohort, examined under restricted and high dietary salt conditions. We employed a tagging single nucleotide variant approach to genotype participants at AGTR1. Our regression model revealed a significant association between the rs2638355 (A/G) variant and salt-sensitive systolic blood pressure (SS-SBP), and rs2638355 increased AGTR1 gene expression. Notably, carriers of the risk-allele of the noncoding regulatory variant rs2638355 exhibited higher systolic blood pressure under high salt diet conditions than nonrisk allele individuals. A sex-stratified analysis showed this salt-driven effect on systolic blood pressure was significant only in females, underscoring the role of dietary salt in modulating genetic effects in this group. Furthermore, a restricted salt diet in these individuals diminished blood pressure and negated the blood pressure phenotype-genotype association. Overall, our findings could aid in pinpointing individuals with salt-sensitive blood pressure among hypertensive patients, especially considering dietary and sex-specific factors.