Abstract Body: Background:

RHTN is defined as blood pressure above goal despite using ≥3 antihypertensive medications. Patients
with RHTN are at an increased risk for cardiovascular (CVD) compared to those with more easily
controlled hypertension (HTN). Blacks With RHTN are at a specifically high risk for CVD.
Mineralocorticoid receptor activation has been found as an important mechanism of RHTN. However,
aldosterone levels are not different in blacks versus whites. The role of 24-hour cortisol-to-cortisone ratios
in this group 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 24-hour urine collection including cortisol and cortisone. Patients with HTN served as a control
group.

Results:

Black patients with RHTN compared to whites had a trend to higher 24h cortisol levels
(17.7±27.6 vs 16.9±14.9, p =0.70, significantly lower 24h cortisone levels (60.45±37.7 vs 75.3±40.0, p
0.000234), and significantly higher 24h cortisol-to-cortisone ratios (0.23±0.14 vs 0.20 ±0.10, p=0.027).
They were younger (53.3±11.6 vs 59.4±12.9 years), more obese (BMI 34.9±7.6 vs 30.8±6.1 kg/m2,
p<0.001), had earlier onset of HTN (35.6±12.5 vs 41.4±11.6 years of age, p<0.001), higher 24-hour
urinary sodium excretion (188.2±92.5 vs 174.9±83.1 mmol, p=0.006) and lower potassium excretion
(54.5 ±28.6 vs 65.5 ±30.5 mmol, p<0.001). Furthermore, they had a significantly higher rate of heart
failure (p=0.000455) and diabetes (p=0.0006).

Conclusion:

Cortisol dysregulation and a higher cortisol-to-cortisone ratio as an index of 11beta HSD2
activity may play a role in black patients with RHTN and may be related to adverse outcomes in this
population.