Japan-Indonesia Collaborative Study of Imidapril on Antiproteinuric Effect in Hypertensive Patients with Chronic Kidney Disease (CKD)

Abstract

Background：Chronic kidney disease(CKD)is a comprehensive disease concept that includes chronic glomerulonephritis such as IgA nephropathy or lupus nephritis, diabetic nephropathy and hypertensive nephrosclerosis. CKD is a risk factor for end stage kidney disease(ESKD)and cardiovascular diseases(CVD). It is considered that angiotensin─converting enzyme(ACE)inhibitors and angiotensin II receptor blockers(ARBs)induce a marked renoprotective effect in patients with CKD. The purpose of the present Japan─Indonesia collaborative study was to evaluate the antiproteinuric effect of imidapril, one of the ACEIs, in hypertensive patients with CKD. Methods：Twenty three hypertensive CKD patients were treated with imidapril and a calcium channel blocker(CCB). Imidapril was added for patients who had been treated with a CCB such as diltiazem at the start of this study. When blood pressure(BP)did not reach the target level (＜130／85 mmHg) , imidapril dosage was increased to 10 mg／day and administered for 12 months. Alternatively, patients were treated with 5─10 mg／day of imidapril. Results：In the imidapril ＋ CCB combination therapy, systolic blood pressure(SBP)and diastolic blood pressure (DBP) were significantly reduced, both at 6 months and at the end of the clinical study. Only DBP reached values below the target level. Urinary albumin excretion (UAE)levels were markedly decreased at 6 and 12 months when compared with the baseline values(0.45 ± 0.54g／g・Cr indicating typical overt proteinuria) and these decreases at both time points were significant. The UAE levels at both 6 and 12 months complied with the diagnostic criteria for microalbuminuria (＜ 0.299 g／g・Cr). Conclusion：In this collaborative study, a combination of imidapril and a CCB, such as diltiazem, significantly reduced BP, and reduced UAE, suggesting strict BP control may induce an efficient decrease in UAE. It appears that imidapril─based therapy has renoprotective effects in hypertensive patients with CKD.