Renal damage in primary aldosteronism: a systematic review and meta-analysis

Objectives: In experimental animal models, exogenous aldosterone excess has been linked to the progression of renal disease. However, the evidence of an increased risk of renal damage in patients affected by primary aldosteronism remains controversial. We aimed at evaluating the association between primary aldosteronism and renal damage through a meta-analysis. Methods: We performed a quantitative review of studies evaluating parameters of renal function in patients affected by primary aldosteronism compared with hypertensive patients without primary aldosteronism and in patients affected by primary aldosteronism before and after treatment. We searched MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials from January 1960 up to April 2019. Results: Forty-six studies including 6056 patients with primary aldosteronism and 9733 patients affected by arterial hypertension without primary aldosteronism were included. After 8.5 years from hypertension diagnosis, patients with primary aldosteronism had an increased estimated glomerular filtration rate (eGFR) compared with hypertensive patients without primary aldosteronism [by 3.37 ml/min IQR (0.82-5.93)] and a more severe albuminuria [standard mean difference 0.55 (0.19-0.91)], resulting into an association with microalbuminuria [odds ratio (OR) 2.09 (1.40; 3.12)] and proteinuria [OR 2.68 (1.89;3.79)]. Following primary aldosteronism treatment, after a median follow-up of 12 months, a reduction in eGFR was observed [by -10.69 ml/min (-13.23; -8.16)], consistent in both medically and surgically treated patients. Similarly, a reduction in albumin excretion and an increase in serum creatinine were observed after treatment. Conclusion: Patients affected by primary aldosteronism, compared with patients affected by arterial hypertension without primary aldosteronism, display a more pronounced target organ damage, which can be mitigated by the specific treatment.