Solution is not simple; sodium-glucose cotransporter-2 inhibitor use in Conn syndrome

In patients with bilateral primary hyperaldosteronism (PA) and those with unilateral PA who are unwilling or unable to undergo adrenalectomy an increase in plasma renin activity (PRA) provided by mineralocorticoid receptor antagonists (MRAs) therapy reflects sufficient antagonism for elevated aldosterone. Sodium-glucose cotransporter-2 inhibitors (SGLT2-i) have cardiovascular, renal protective properties and some clinical data have shown an increase in PRA levels with SGLT2-i. Here, we present our experience of using SGLT2-i in PA patients with suppressed PRA despite 100 mg/day spironolactone therapy.

We prospectively evaluate the laboratory values of seven patients who were diagnosed with bilateral hyperaldosteronism. All of them were diabetic and had an HbA1c <7% with metformin treatment alone. Spironolactone was started in all of the patients after diagnosis and although the dose was increased to 100 mg/day, PRA levels remained <1 ng/ml/h. Metformin treatment was changed to empagliflozin in all patients and PRA was checked again at the sixth month of treatment.

Metformin treatment was changed to empagliflozin in all patients and PRA was checked again at the sixth month of treatment. Mean PRA levels were 0.464 ± 0.189 ng/ml/h before the treatment change and increased to mean 3.257 ± 1.881 ng/ml/h in the sixth month ( P  = 0.008). The mean PRA was >1 ng/ml/h except for one patient in the sixth month of treatment.

Larger molecular and clinical studies are needed to understand whether the increase in PRA after empagliflozin treatment indicates interference, whether spironolactone treatment has become more effective, or whether empagliflozin has aldosterone receptor antagonism apart from its known effects.