Comparative effects of adding thiazide diuretics versus calcium channel blockers on Angiotensin-converting enzyme inhibitors for renal events among diabetic with hypertensive patients at the University of Gondar comprehensive specialized referral hospital.

Abstract

Abstract Background: The co-existence of diabetes with hypertension increases the risk of renal dysfunction, and atherosclerotic cardiovascular outcomes. For preventing these consequences, an appropriate combinations of antihypertensive agents are the main stay of therapy. Objective: The primary aims of this study was to compare the effects of thiazide diuretics versus Calcium Channel blockers on the renal events and associated factors after adding on Angiotensin converting enzyme inhibitors among diabetic with hypertensive patients attending at the University of Gondar hospital outpatient department from January 2015 to December 2019. Methods: A hospital-based comparative retrospective cohort study was conducted from March 17 to June 19, 2020 on the medical records of diabetic with hypertension patients attended chronic follow up clinic of UOGCSH between January 2015 and December 2019. Descriptive and analytical statistics were utilized to illustrate comparisons in the study groups. Kaplan-Meier and a log- rank test was used to plot the survival analysis curve. Potential predictors on the renal events was examined using cox proportional hazards model. The significant renal function was defined as reduction in eGFR levels by ?30% from the baseline. A 5% level of significance was used. Result: A total of 404 patients were involved in the final analyses; and participants were recruited with a 1:1 ratio. The mean eGFR levels (measured by ml/min/1.73m VIII

2 ) were significantly higher in patients taking CCBs based regimens at the 2 nd , 3 rd and 5 th years of the follow-ups with 6.92, P=0.026; 9.5, P=0.018, and 18.02, P=0.005, respectively. The CCBs group had a median change of 18.8ml/min/1.73m 2 higher in eGFR (last minus initial) at the end of the follow-up than HCT group (P<0.001). The HCT users had a shorter survival probability overtime to develop the events compared with CCBs group (X 2 =8.64; P=0.003). The CCBs based regimen prevented the risks of declining in renal function by 56.3% than HCT (AHR (95% CI) = 0.437 (0.268-0.714), P=0.001). The risks of declining in eGFR levels were 90.3% higher for the patients whose initial SBP levels were more than 150mmHg (AHR (95% CI) = 1.902 (1.183-3.057), P=0.008). Conclusion: Compared with HCT, patients on CCBs had a significantly lower risks of renal events. However, both groups appeared with the same cardiovascular events. Hydrochlorothiazide and higher initial SBP levels were significantly associated with eGFR reductions. Key words: Ethiopia, Thiazide diuretics, calcium channel blockers, diabetes, hypertension