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.