Hyperaldosteronism Among Black and White Subjects With Resistant Hypertension

TLDR

Primary hyperaldosteronism may be more common than previously thought, yet prior studies relied mainly on plasma aldosterone/plasma renin activity ratios without universal suppression testing. The study prospectively evaluated 88 resistant‑hypertension patients, measuring 24‑hour urinary aldosterone under high salt intake, baseline plasma renin activity, and plasma aldosterone, confirming hyperaldosteronism when PRA < 1.0 ng/mL/h and urinary aldosterone > 12 µg/24 h with sodium excretion > 200 mEq/24 h. Twenty percent of the cohort had primary hyperaldosteronism, with equal prevalence in black and white subjects; all 14 treated with spironolactone achieved significant blood‑pressure reductions, and a PAC/PR ratio > 20 yielded 89 % sensitivity and 71 % specificity, underscoring hyperaldosteronism as a common cause of resistant hypertension in both races.

Abstract

Recent reports suggesting that the prevalence of primary hyperaldosteronism may be higher than historically thought have relied on an elevated plasma aldosterone concentration/plasma renin activity ratio to either diagnose or identify subjects at high risk of having primary hyperaldosteronism and have not included suppression testing of all evaluated subjects. In this prospective study of 88 consecutive patients referred to a university clinic for resistant hypertension, we determined the 24-hour urinary aldosterone excretion during high dietary salt ingestion, baseline plasma renin activity, and plasma aldosterone in all subjects. Primary hyperaldosteronism was confirmed if plasma renin activity was &lt;1.0 ng/mL per hour and urinary aldosterone was &gt;12 μg/24-hour during high urinary sodium excretion (&gt;200 mEq/24-hour). Eighteen subjects (20%) were confirmed to have primary hyperaldosteronism. The prevalence of hyperaldosteronism was similar in black and white subjects. Of the 14 subjects with confirmed hyperaldosteronism who have been treated with spironolactone, all have manifested a significant reduction in blood pressure. In this population, an elevated plasma aldosterone/plasma renin activity ratio (&gt;20) had a sensitivity of 89% and a specificity of 71% with a corresponding positive predictive value of 44% and a negative predictive value of 96%. These data provide strong evidence that hyperaldosteronism is a common cause of resistant hypertension in black and white subjects. The accuracy of these results is strengthened by having done suppression testing of all evaluated subjects.