Aims: Nondiabetic chronic kidney disease (CKD) is the leading major cause of end-stage renal disease in developing countries including China. Among the 5 stages of CKD, it is critical to retard the progression of stage 3 because renal disorder could accelerate aggravation behind that stage. Data suggest that high dosages of angiotensin receptor blockers (ARBs) could retard the progression of renal disease in hypertensive and/or diabetic patients. Nevertheless, in daily practice of nephrology, quite a number of nondiabetic patients with CKD who are normotensive do not tolerate even moderate dosages of ARBs because of adverse effects such as systemic hypotension, epically for Chinese patients. The aim of this study was to investigate the renoprotective effects of relatively low dosages of ARBs in normotensive Chinese patients with nondiabetic stage 3 CKD.
Methods: A prospective, randomized, parallel-group, open-label study was performed over a period of 12 months. A total of 238 enrolled patients were randomly allocated to treatment with losartan 50 mg (n = 119) or placebo (n = 119). All patients were followed up at 2-month intervals. At each visit, blood pressure was measured, and urinalysis and serum biochemistry tests were performed.
Results: Finally, 112 patients given losartan and 114 patients given placebo completed the study. In the losartan group, there was a significant and biphasic time-dependent decline in proteinuria during therapy (1.72 ± 0.47 to 0.99 ± 0.48 g/d; P < 0.001). Conversely, placebo did not simultaneously change the amount of proteinuria (1.73 ± 0.49 to 1.64 ± 0.50 g/d; P = 0.337). Estimated glomerular filtration rate remained stable during the entire study period in the patients given losartan (44.8 ± 8.1 to 44.1 ± 7.7 mL/min per 1.73 m2; P = 0.120) but were significantly reduced in the placebo group (44.5 ± 8.5 to 39.1 ± 7.4 mL/min per 1.73 m2, P < 0.001). The changes in blood pressure were kept constant in the 2 groups. All adverse events were minimal and nonfatal.
Conclusions: For normotensive patients with nondiabetic stage 3 CKD, therapy with a daily dose of losartan, 50 mg, may perform effective renoprotection without changing blood pressure and be generally safe and well tolerated.