P0210ASSOCIATIONS BETWEEN CHANGES IN RENIN ACTIVITY AND ALDOSTERONE LEVELS AND CHANGES IN KIDNEY FUNCTION AFTER TREATMENT FOR PRIMARY ALDOSTERONISM: A LARGE MULTICENTER COHORT STUDY IN JAPAN

Abstract Background and Aims Greater reduction in estimated glomerular filtration rate (eGFR) after treatment for primary aldosteronism (PA) reflects improvement of glomerular hyperfiltration associated with PA and leads to better patient outcomes. However, little is known regarding the mechanisms underlying eGFR reduction after treatment for PA. Method We analyzed data from the nationwide PA registry in Japan. Patients were assigned to adrenalectomy (n=419) and mineralocorticoid receptor (MR) antagonist (n=674) groups. We assessed associations between changes in BP, plasma renin activity and aldosterone levels, and eGFR after treatment for both groups. Results Reduction in eGFR after treatment was greater in the surgical compared to MR antagonist treatment group (median -11.0; 95% CI, -12.2 to -9.8 ml/min/1.73 m2 vs. -3.5; 95% CI, -4.3 to -2.7 ml/min/1.73 m2; p <0.001). In a multivariable linear regression, the adjusted betas (95% confidence interval) for change in eGFR after treatment for each standard deviation higher level of plasma renin activity and aldosterone were -2.12 (-4.10, -0.14) and 2.41 (1.20, 3.62) ml/min/1.73 m2, respectively, in the adrenalectomy group, and -0.65 (-1.28, -0.02) and –0.64 (-2.04, 0.76) ml/min/1.73 m2, respectively, in the MR antagonist group. Plasma renin activity Change in mean arterial pressure after treatment was not associated with change in eGFR in either group. Conclusion Changes in plasma renin activity and aldosterone levels but not BP, after treatment for PA were associated with greater reductions in eGFR. Post-treatment improvements in glomerular hyperfiltration may be attributable to suppressed MR activity within the kidneys, not to reductions in systemic blood pressure. It is important for clinicains not only to treat PA, but also to confirm adequate suppressed MR activity after treatment for correction of glomerular hyperfiltration.