Endocrine Abstracts

Background

Primary aldosteronism (PA) constitutes the most common form of hormonal hypertension. However, it is very often misdiagnosed and incorrectly managed. Detection rates are inadequately low and the interpretation of hormonal results is impossible in some patients. Subtype evaluation with its several limitations represents another problematic issue. We describe the cases of two young primary aldosteronism patients with complicated history and a few-year follow-up until the final diagnosis.

Case description

CASE 1. 26 year-old female with grade I arterial hypertension, still hypertensive on betaxolol, with hypokalaemia despite potassium supplementation, was admitted for hormonal testing. 4 years earlier she had undergone evaluation for primary aldosteronism with strongly positive screening test results (aldosterone 23 ng/dl, plasma renin activity, PRA 0.312 ng/ml/min, aldosterone-to-renin ratio, ARR 74), but no further conclusions. Abdomen computed tomography (CT) had been normal and she hadn’t been given spironolactone because of her reproductive age. She was allergic to iodinated contrast agents, so adrenal venous sampling (AVS) hadn’t been performed. We repeated biochemical testing which again confirmed primary aldosteronism. Another abdomen CT revealed left adrenal adenoma sized 7.5 mm in diameter. The patient was finally successfully adrenalectomized with biochemical and clinical remission. CASE 2. 37 year-old male was referred to the Department of Endocrinology due to resistant hypertension despite 4-drug therapy (with thiazide) for the last 2 years, associated with inadequate, deep hypokalaemia. Laboratory work-up revealed medium-high, non-suppressible aldosterone levels, but with repeatedly non-suppressed direct renin concentrations (18–110 µIU/ml). The results didn’t change despite drug withdrawal, making PA diagnosis questionable. Renal stenosis was excluded and adrenal glands were described as normal in CT. Two years later, the evaluation was performed again. The hormonal profile changed as direct renin concentrations were substantially lower (2, 95–15 µIU/ml). ARR converted to positive and saline infusion test confirmed PA. Another CT revealed left adrenal adenoma sized 9 mm in diameter. NP59 scintigraphy showed nonspecific bilateral radionuclide uptake, so the patient is waiting for AVS.

Conclusions

Hypokalaemia of unknown origin in young patients is very indicative of PA. Non-suppressible aldosterone levels with non-suppressed renin or PRA are the laboratory findings of unexplained significance. In the case 2, they might have represented an early stage of the disease. Regular ambulatory check-up with repeated hormonal screening as well as another radiological evaluation may enable the final diagnosis in high-risk, but somehow unequivocal, cases.