Effect of Early Spironolactone Treatment on Albuminuria in Patients with CKD and Hypertension: A Randomized Controlled Trial

Background: Recent research emphasizes non-steroidal mineralocorticoid receptor antagonists (MRAs) for slowing chronic kidney disease (CKD) progression and reducing albuminuria. However, there is limited research on the efficacy of spironolactone, a more accessible and low-cost steroidal MRA. Methods: This randomized controlled trial was conducted at Bhumibol Adulyadej Hospital, Bangkok, Thailand, from October 2023 to February 2024. Participants had hypertension and CKD stage 2-3 (eGFR 30-89 ml/min/1.73 m2) and were already receiving ACEI or ARB medication. Eleven patients were enrolled: five received spironolactone, and six did not. Both groups received standard hypertension care. Follow-up evaluations were conducted at 3 months. Results: Patients receiving spironolactone showed a mean decrease in urinary albumin-to-creatinine ratio (UACR) of 655.00 ± 621.82 mg/g, compared to 320.50 ± 504.87 mg/g in the control group, resulting in a difference of 295.92 mg/g (95% CI: -942.33 to 350.49; p = 0.370). The change in eGFR was -8.64 ± 9.12 ml/min/1.73 m2 in the spironolactone group and -3.38 ± 14.62 ml/min/1.73 m2 in the control group, with a difference of -5.26 ml/min/1.73 m2 (95% CI: -16.77 to 6.69; p = 0.400). The change in systolic blood pressure (SBP) was -21.80 ± 20.64 mmHg vs. -22.00 ± 24.79 mmHg (difference: 0.20 mmHg, 95% CI: -39.74 to 10.49; p = 0.254). The mean serum creatinine levels were 1.61 ± 0.90 mg/dL in the spironolactone group and 1.10 ± 0.14 mg/dL in the control group, differing by 0.51 mg/dL (95% CI: 0.07 to 0.95; p = 0.009). The mean potassium levels were 4.90 ± 0.43 mmol/L and 4.23 ± 0.41 mmol/L, respectively, differing by 0.67 mmol/L (95% CI: 0.22 to 1.08; p = 0.003). Conclusion: Spironolactone did not significantly decrease albuminuria in hypertensive CKD patients already on ACEI or ARB therapy but was associated with increased potassium and creatinine levels. The study's findings are limited by the small sample size and short duration.