Renal outcomes of diabetic patients treated with combination therapy of ACE inhibitors plus either thiazide diuretics or calcium channel blockers: comparative retrospective cohort study in Northwestern Ethiopia.

OBJECTIVE The study determined the comparative renal functions on patients with diabetes treated with ACE inhibitors (ACEIs) plus either thiazide diuretics or calcium channel blockers (CCBs) in Northwestern Ethiopia. DESIGN Retrospective cohort study design was employed to collect the data from medical records of patients with diabetes followed for 1-5 years (N=404). SETTING The medical records of patients in chronic diabetic follow-up clinics of the hospital. PARTICIPANTS All the patients with diabetes medical records in Northwestern Ethiopian specialised hospital. MAIN OUTCOME MEASURES Exposures were ACEIs plus thiazide diuretics or CCBs collected from March to June 2020. Outcomes were defined as declining in estimated glomerular filtration rate (eGFR) values by ≥30% from the baseline recorded from 2015 to 2019. Descriptive and analytical statistics were illustrated to compare the study groups. Kaplan-Meier with log- rank test was used to plot the survival analyses curve. Potential factors substantially associated to renal events were examined using cox proportional hazards model. RESULT About 20% of patients developed renal events and significant numbers were from hydrochlorothiazide (HCT) users. The mean eGFR levels were significantly higher in patients on CCBs users over the follow-up years compared with HCT-based users. The CCBs users had an 18.8 mL/min/1.73 m2 higher in eGFR levels at the end of the follow-up period than HCT users (p<0.001). HCT users had shorter survival probability overtime to develop the outcomes compared with CCBs users (p=0.003). The CCBs-based regimen prevented risks of declining in renal function by 56.4% than HCT (p=0.001). Hazards of declining in eGFR levels were 93% higher for the patients with initial systolic blood pressure (SBP) levels were more than 150 mm Hg (p=0.006). CONCLUSION Compared with HCT, patients on CCBs had significantly prevented risks of renal events. However, both groups appeared with the same cardiovascular events. HCT-based regimen and higher initial SBP levels were significantly associated with eGFR reductions.