Impact of primary aldosteronism on kidney function: results from the SPAIN-ALDO registry.

Aim: To evaluate the impact of aldosterone excess on renal function in individuals with primary aldosteronism and to compare its evolution after surgery or mineralocorticoid receptor antagonist (MRA) treatment.

Methods: A multicentre, retrospective cohort study of primary aldosteronism patients in follow-up in 36 Spanish tertiary hospitals, who underwent specific treatment for primary aldosteronism (MRA or adrenalectomy).

Results: A total of 789 patients with primary aldosteronism were included, with a median age of 57.5 years and 41.8% being women. At primary aldosteronism diagnosis, the prevalence of chronic kidney disease (CKD) was 10.7% ( n  = 84), with 75% of cases classified as state 3a ( n  = 63). Primary aldosteronism patients with CKD had a longer duration of hypertension, a higher prevalence of type 2 diabetes, dyslipidaemia, cardiovascular events, hypokalaemia, and albuminuria. Unilateral adrenalectomy was performed in 41.8% of cases ( n  = 330), and 459 patients were treated with MRA. After a median follow-up of 30.7 months (range 13.3-68.4), there was a significant decline in the estimated glomerular filtration rate (eGFR) in operated patients and those receiving MRA. During follow-up, 24.4% of patients with CKD at the time of primary aldosteronism diagnosis had normalized renal function, and 39% of those with albuminuria had albuminuria remission. There were no differences in renal function or albuminuria regression between the two therapy groups. However, development of albuminuria was less common in operated than in medically treated patients (0 vs. 6.0%, P  = 0.009).

Conclusion: CKD affects around 10% of the patients with primary aldosteronism, with a higher risk in individuals with long-term hypertension, type 2 diabetes, dyslipidaemia, cardiovascular events, hypokalaemia, and albuminuria. At short-term, both MRA and surgical treatment lead to a reduction of renal function, but adrenalectomy led to higher renal protection.