Abstract Body: RHTN is defined as blood pressure above goal despite using ≥3 antihypertensive medications. Patients with RHTN are at an increased risk for CVD compared to those with more easily controlled hypertension (HTN). High sodium intake and higher 24h urinary (U) sodium (Na) potassium(K) ratio is associated with higher CVD risk. The role of this ratio in RHTN has not been investigated.

Methods: We conducted a cross-sectional analysis of a large cohort of 2397 black and white patients with RHTN who were referred to the RHTN Clinic at the University of Alabama at Birmingham and who underwent a 24h urine collection. Patients with HTN served as a control group.

Results: Patients with RHTN had significantly higher 24h UNaK ratio than patients with HTN (3.2±1.6 vs 3.6 ±2.0, p <0.001 ) and had an earlier onset of HTN (38.8±13.7 years (yrs) vs 47.6±16.2 yrs, p=0.001) and longer duration 17.6±11.2 vs 12.0±10.7 yrs, p=0.001), higher BMI (32.6±7.2 vs 29.98±6.5 kg/m2), and 24-hourUNa (181±88 vs 164±77 mmol, p=0.01). Within the RHTN group (n=1340) females had a significant higher 24h UNaK ratio than males (3.5±1.9 vs 3.2±1.7, p =0.006) and blacks had a significant higher 24h UNaK ratio than whites (3.0±1.6 vs 3.9±2.0, p<0.001).

Conclusion: Higher 24h UNaK ratio as index of higher sodium and lower potassium intakes were found in patients with RHTN as well as resistant hypertensive females and blacks and may explain certain higher CV risks in these populations.