Comparison Of The Effects Of Losartan And Enalapril On Renal Function In Adults With Chronic Kidney Disease At Kenyatta National Hospital

Abstract

Background: Chronic kidney disease is an increasing health concern associated with a high risk of adverse outcomes. The three most common causes of chronic kidney disease are diabetes mellitus, hypertension and glomerular disease. The renin angiotensin aldosterone system plays a key part in the progression of renal failure. Renin angiotensin aldosterone system blockade with angiotensin II converting enzyme inhibitors and the angiotensin II receptor blockers are the gold standards of treatment in patients with either diabetic or non diabetic nephropathies. However, a head to head comparison of the two classes of drugs has not been done locally to determine their effects on renal function. Objective: The main objective of this study was to compare renal function in hypertensive patients with diabetic chronic kidney disease receiving enalapril and losartan containing regimens at Kenyatta National Hospital. Methodology: We conducted a retrospective analytic cohort at the Kenyatta National Hospital from January 2006-December 2012. The study population consisted of male and female patients who were 18 years of age or older with chronic kidney disease, hypertension and diabetes. A total of 200 patients (1 16 for enalapril and 84 for losartan) were enrolled after meeting the inclusion criteria. Data collected was entered into an access data base, cleaned and transferred to IBM SPSS version 20 for analysis. Results: The patient gender ratio was approximately 1:1, although there was a slight female preponderance (50.5%) (p=0.868). Median age for all the patients was 63 years (rangeI8- 95 years) and greater than three quarters of the patients were more than 50 years old. Most patients (91%) had type 2 diabetes (p=0.015). Patients on losartan were found to be at a higher risk of doubling of serum creatinine (Adjusted HR=1.572; 95% CI: (1.015-2.434); p=0.043) than those on enalapril. Survival probabilities determined by the Kaplan-Meir method revealed that the median time to doubling was 24 months for the cohort. There was a significant difference in

survival probabilities between the two arms - losartan 18 months, enalapril 36 month (p=0.046). Lower baseline serum creatinine was found to be highly predictive of doubling of serum creatinine (Adjusted HR=0.996; 9S% CI: (0.996-1.00); p=O.O16). Significant differences in the means of the estimated glomerular filtration (eGFR) rates between the two arms were observed at months 3 (p=0.04S) and month 6 (p=0.046) of follow up. Univariate analysis of variance revealed that increased length of therapy with either agent was protective (p=O.007). A comparison of the changes in the levels of proteinuria between the two arrns did not reveal significant differences for most of the follow up period except for month IS (p=O.OS3). Conclusions: Patients on losartan regimens were at a higher risk of experiencing a doubling of serum creatinine then those on enalapril regimens. Renal function was better preserved in patients on the enalapril regimens compared to those on losartan regimen. Increased length of therapy was also found to be protective. We recommend the use of enalapril as first line therapy in type 2 diabetic chronic kidney disease patients with hypertension.