Association between rs4673 and blood pressure response to acute saline infusion in Chinese population

This study investigated the relationship between rs4673 of the nicotinamide adenine dinucleotide phosphate oxidase p22PHOX gene and blood pressure (BP) response to acute salt loading in a Chinese population diagnosed with essential hypertension. An acute salt loading test was performed using 2 L of normal saline (NS) infused over 4 hours. BP and heart rate were recorded immediately after NS infusion and hourly for the next 3 hours. Data analysis was performed using the chi-squared test, Student t test, and multivariable regression. A total of 159 patients were analyzed, including 129 with the CC genotype, 29 with the CT genotype, and 1 with the TT genotype. Individuals carrying the T allele exhibited greater tolerance to BP increases caused by 2 L NS infusion. Specifically, the systolic blood pressure change for T carriers was 0.26 ± 9.72 mm Hg, compared to 6.82 ± 11.65 mm Hg for those with the CC genotype (P = .005). Diastolic blood pressure changes were -3.35 ± 7.52 mm Hg in T carriers versus 1.38 ± 7.62 mm Hg in CC genotype carriers (P = .003), and mean arterial pressure changes were -2.13 ± 7.85 mm Hg in T carriers compared to 3.19 ± 7.81 mm Hg in CC genotype carriers (P = .001). These significant differences persisted after adjusting for gender, age, smoking, drinking, and baseline BP. Interestingly, not all subjects experienced increased BP following NS loading; 86.82% in the CC group did, versus 66.67% of T allele carriers (P = .014). The findings suggest that individuals carrying the T allele are less likely to be salt-sensitive, as indicated by a diminished BP response to acute saline infusion. This contributes to the understanding of the genetic factors that influence salt sensitivity in essential hypertension.