The association of urinary sodium with incident apparent treatment resistant hypertension among African Americans: findings from the Jackson Heart Study

Hypertension is a leading cause of cardiovascular disease and disproportionately affects African American (AA) adults. Apparent treatment-resistant hypertension (aTRH) is highly prevalent in this population. Sodium intake is associated with blood pressure (BP) levels, yet the relationship between sodium and the risk of developing aTRH in AA adults remains unclear. This study examined the association between 24-hour urinary sodium excretion and incident aTRH among AA adults with hypertension, using data from the Jackson Heart Study (JHS). The JHS included 5306 self-identified AA adults from Jackson, Mississippi, with data collected from 2000 to 2013. This analysis included 452 participants with baseline hypertension and complete urinary excretion and medication data. Sodium excretion was categorized into quartiles: Q1 (253 to 2530 mg/day), Q2 (2553 to 3657 mg/day), Q3 (3680 to 4692 mg/day), and Q4 (4715 to 9775 mg/day). A semi-parametric proportional hazards model was used to determine the association between sodium excretion and incident aTRH. Participants had a mean age of 63 years, and 27.7% were men. Over a median follow-up of 7.5 years, 123 participants (27.2%) developed aTRH. The incidence of aTRH was 25.7%, 24.8%, 29.2%, and 29.2% in Q1, Q2, Q3, and Q4 of urinary sodium excretion, respectively. In adjusted models, there was no significant association between urinary sodium excretion and incident aTRH HRs (95% CIs): Q2 = 0.71 (0.34, 1.46), Q3 = 1.02 (0.50, 2.06), Q4 = 0.95 (0.46, 2.00); P = 0.166. Among AA adults with treated hypertension, sodium intake, as measured by 24-hour urinary sodium excretion, was not significantly associated with incident resistant hypertension.