The effects of irbesartan and enalapril on the renal function in patients with essential hypertension

Objective To evaluate the effects of angiotensinⅡreceptor antagonist(ARB) and angiotensin converting enzyme inhibitor(ACEI) on the renal function in essential hypertension(EH) patients.Methods A randomized,single blind and parallel study was performed in our study.After 2 weeks washout run in period,60 patients were divided into 2 groups randomly,and underwent 16 week continuously therapy,which either 150 mg irbesartan (n = 30) or 5 mg enalapril(n = 30) once per day.Dose doubling was required if diastolic blood pressure (DBP)≥90 mm Hg(1 mm Hg =0.133 kPa) after 4 weeks.The blood pressure,heart rate(HR),symptoms and signs were recorded.The serum creatinine(Cr),blood urea nitrogen(BUN),endogenous creatinine clearance rate (Ccr),24h urine protein excretion total urine protein(UTP),albumin(Alb),serum and urineα_1-microglobulin andβ_2-microglobulin(α_1-MG andβ_2-MG) excretion,urine sodium and potassium were compared before and after treatment. Another 20 healthy subjects were enrolled as normal control group.Results(1) The irbesartan and enalapril reduced the blood pressure significantly in essential hypertension after 16 week continuously treatment(P0.05). (2) Before treatment,the Ccr was significantly lower in EH group than that in control group(P0.01),while the UTP,Alb,serum and urineα_1-MG andβ_2-MG were significantly higher in EH group than those in control group (P0.05 or P0.01).(3)Both irbesartan and enalapril treatment group decreased UTP and Alb,serum and urineα_1-MG andβ_2-MG after 16 week treatment(P0.05 or P0.01).For those whose hypertension course were more than 10 years,the changes were more significant(P0.05).(4)The prevalence of cough in irbesartan treatment group was significantly lower than that in enalapril treatment group(6.7%vs 26.7%,P0.01).Conclusion (1) In the early stage of hypertension,renal function may be damaged.(2) It suggested that the irbesartan could improve renal function effectively as well as enalapril.