Primary aldosteronism: Changes in cystatin C-based kidney filtration, proteinuria, and renal duplex indices with treatment

Objectives: To obtain information about the effect of prolonged aldosterone excess on kidney function. Methods: We determined kidney function changes defined by cystatin C-based estimations of glomerular filtration rate (CysC-GFR). Pretreatment proteinuria and intrarenal Doppler velocimetric indices in primary aldosteronism were examined and followed after adrenalectomy or spironolactone treatment. Results: This prospective, multicenter study included 130 primary aldosteronism patients (56 men; age, 49.9±13.4 years: 100 with adenoma and 30 with idiopathic hyperaldosteronism) and 73 essential hypertension patients (36 men; age, 51.4±14.8 years) as controls. Patients with primary aldosteronism had higher CysC-GFR (P<0.05) and heavier proteinuria (0.042) than those with essential hypertension. With primary aldosteronism, a higher aldosterone-renin ratio (odds ratio, OR=7.85, P=0.008) was independently related to pretreatment CysC-GFR. The factors related to pretreatment proteinuria included CysC-GFR (OR,-0.006, P=0.001), plasma aldosterone concentration (OR, 0.004, P=0.002), and duration of hypertension (OR, 0.016, P=0.032). Duration of hypertension was also independently correlated with the pretreatment resistive index among primary aldosteronism patients (OR, 0.004, P=0.035). CysC-GFR (all, P<0.05), proteinuria (P<0.001), and resistive index (P<0.001) decreased 1 year after adrenalectomy but not with spironolactone treatment. Conclusion