Effect of Angiotensin Receptor Blocker and Angiotensin Converting Enzyme Inhibitor on Kidney Function and Blood Potassium Level in Indonesian Type 2 Diabetes Mellitus with Hypertension: A Three-Month Cohort Study

National formulary restrictions in Indonesia (2019) require estimated glomerular filtration rate (eGFR) of less than 60 mL/min/1.73 m to be able to prescribe telmisartan and valsartan and ACE-I intolerance to be able to prescribe irbesartan and candesartan. These restrictions are based on economic considerations and differ from American Diabetes Association (ADA) (2020) guidelines which allow equal use of angiotensin II receptor blockers (ARB) and angiotensin-converting enzyme inhibitors (ACE-I) without restriction. Since there is a need to evaluate the different effects of ACE-I and ARB in the Indonesian hypertensive type 2 diabetes mellitus (T2DM) population, we compare their effects on urine albumin-to-creatinine ratio (UACR), estimated glomerular filtration rate (eGFR), and blood potassium level. A prospective cohort study at RSUPN Dr. Cipto Mangunkusumo Hospital was conducted in 123 T2DM patients. We followed the study subjects prospectively for three months using a validated questionnaire, health record, and laboratory data. After 3 months of observation, there were no significant changes, except increased BMI values (p = 0.046) in the ACE-I group, and decreased LDL value (p = 0.016) and HDL value (p = 0.004) in the ARB group. Multivariate analysis showed that the consumption of ACE-I or ARB was not associated with a decrease/constant of UACR or increase potassium level, even after adjusting by confounding variables. Interestingly, we found ARB was more likely to increase eGFR, but the significance was lost once the duration of ACE-I/ARB use was entered into the model. In addition, BMI >25 kg/m was a significant factor associated with decreased/constant UACR, maleness was significant for increased eGFR, and declining systolic blood pressure for increase in potassium level. ACE-I and ARB have a similar effect on UACR and blood potassium level, but ARB slightly increased eGFR compared to ACE-I within three months of consumption.