Endocrine Abstracts

Introduction: Endocrine Society guideline indications for screening (EGS) of hypertensive patients for hyperaldosteronism are not universally followed in clinical Endocrinology. We present a series of patients with hyperaldosteronism, diagnosed following strict EGS compliance.

Methods: Retrospective. Following compliance with EGS in all patients attended in a general Endocrinology outpatient clinic, 70 hypertensive patients were diagnosed with hyperaldosteronism over an 8-year period. Screening, with determination of the Aldosterone (RIA)/direct renin (RIA) ratio (ARR), was considered positive when ≥20 in patients on hypertension medication, excluding spironolactone, eplerenone, amiloride. The 2-hour 25 mg captopril test was performed following a minimum of 2 weeks solely on doxazosin, slow-acting verapamil, and/or hydralazine, at least 6 weeks off spironolactone, eplerenone, amiloride. Hyperaldosteronism was diagnosed when the 2-hour aldosterone level (in pg/ml) was ≥130, and/or the 2-hour ARR was ≥50. Interquartile Range in brackets.

Results: 40/70 (57.1%) women, mean age: 63.01 (SD:11.9). Hypertension diagnosed 12.6 (SD: 10.8) years earlier.

Reasons for Referral: Thyroid disease: 19/70 (27%), Diabetes 14/70 (20%), normokalemic hypertension 10/70 (14.3%), obesity 5/70 (7.1%), first-degree relatives (FDR) of hyperaldosteronism patients 5/70 (7.1%), adrenal incidentaloma 4/70 (4.7%), hyperparathyroidism 4/70 (5.7%), hypokalemic hypertension 2/70 (2.8%), others 7/70 (10%).

Indications for screening: Severe hypertension 35 (50%), moderate hypertension 31 (44.3%), resistant hypertension 17 (24.3 %), spontaneous hypokalemia 6 (8.6%), diuretic-induced hypokalemia 13 (18.6 %), hypertension < 40 years of age 10 (14.3 %), FDR 6 (8.6%), Incidentaloma 5 (7.1 %). 35/70 (50%) presented 1 indication for screening, 22 (31.4 %) had 2, and 13 (18.5%) had ≥3. The latter presented a higher 2-hour median serum aldosterone: 214 [169.3-350.8] versus those with 2:174 [139.5-245.5] or 1 indication: 147 [120-181.5] P = 0.008. Moderate hypertension was the sole indication in 16/70 (22.9%). The median screening ARR was higher in patients with resistant hypertension: 109 [41.5-232] than in the rest: 55 [35.15-92.13], P = 0.047. Median aldosterone screening levels were higher in patients with severe hypertension: 248[152-338] than in the rest:190[132-245], P = 0.028, as was 2-hour serum aldosterone: 201 [141-279.5] versus 151 [121-186.5], P = 0.016.

Conclusions: Almost half the patients diagnosed with hyperaldosteronism in Endocrine Clinic had been referred for treatment of thyroid disease or Diabetes. Only 8.6% of patients presented spontaneous hypokalemia. Given the elevated morbimortality associated with hyperaldosteronism, Endocrinologists should study ALL their hypertensive patients presenting indications for screening, regardless of the reason for referral. Screening should not be limited to patients with adrenal incidentaloma or hypokalemia.