Endocrine Abstracts

Background: Primary hyperaldosteronism (PHA) is the most frequent type of endocrine hypertension with a prevalence that is continuously rising. Following the introduction of diagnostic tests that consider both the adrenocorticotropic hormone effect andrenin–angiotensin–aldosterone system (RAAS), the post-dexamethasone saline infusion test (D-SIT) and the overnight dexamethasone, captopril, valsartan test (DCVT) using pharmaceutical RAAS blockade, a higher prevalence of PHA was found.

The aim of the study: To validate in the utility of the newly introduced diagnostic tests in pre- and post-surgical setting. The normal cutoffs values post-D-SIT were for aldosterone 67.59 pmol and for aldosterone-to-renin-ratio (ARR) 9.74 pm/mU/l, whilst post-DCVT for aldosterone 85 pmol/l and for ARR 9 pmol/IU.

Results: We studied 41 patients (16 males), with median (IQR, range) age 50 (16, 35–74) years. The median size of the adenoma resected was 2.1 (2.5, 1–6.5) cm, and in 21 patients was left-sided. Twenty-nine out of 31 were cured by the D-SIT, with aldosterone suppression; 4 patients had ARR >9.74 pm/mU/l but with suppressed aldosterone levels. In 6 patients PHA was diagnosed by DCVT criteria and one by both DSIT and DCVT; 2 patients were found cured post-adrenalectomy by DCVT criteria whereas the rest of the patients displayed low blood pressure measurements post-surgery. Overall, only 2 patients failed to be cured post-surgery implying an adrenalectomy success rate of 95.1%. In 40 patients post-adrenalectomy, 12 (30%) did not change their therapeutic anti-hypertensive status (remained without treatment if not previously treated or retained the same drugs and doses), 23 (57.5%) showed improvement (discontinued their anti-hypertensive treatment or reduced number and doses of anti-hypertensive drugs) and 5 (12.5%) had deterioration (anti-hypertensive treatment or drugs dose increase). A subset of 15 patients out of 32 diagnosed by D-SIT criteria did not suppressed cortisol levels post-dexamethasone suggesting a high percentage of mixed adenoma. The majority 9 patients had cortisol levels between 51 and 138 nmol/l whilst 6 patients had > 150 implying autonomous cortisol secretion. Post-surgery, all 33 patients submitted on D-SIT suppressed cortisol levels.

Conclusion: The present study is a proof of concept for the validity of the newly introduced diagnostic tests for PHA in the clinical practice. The novel tests show a similar rate of clinical and biochemical response post-adrenalectomy, but may better discriminate the cases that may recur.