Antiproteinuric effect of losartan in non-diabetic renal disease is not dependent on ACE insertion/deletion polymorphism

Background: The antiproteinuric effect of angiotensin-converting enzyme (ACE) inhibitors appears to vary depending on the ACE insertion (I)/deletion (D) genotype in non-diabetic nephropathy. This interaction may be overcome by using an angiotensin II receptor blocker. We evaluated the short-term antiproteinuric effect of losartan according to the ACE I/D genotype in patients with non-diabetic proteinuric renal diseases. Methods: Ninety-nine (II/ID/DD: 36/52/11) non-diabetic patients with overt proteinuria were enrolled. The patients received losartan 50 mg daily followed by 100 mg in two treatment periods each lasting 12 weeks. Clinical parameters including proteinuria were measured at baseline and at the end of each period. Results: At baseline each genotype (II/ID/DD) had comparable mean arterial blood pressure (mean ± SD) 103.2 ± 11.1/102.7 ± 10.6/104.1 ± 15.3; proteinuria (geometric mean, 95% CI, mg/day) 1,839 (1,518-2,227)/1,998 (1,683-2,372)/1,613 (1,072-2,427), and creatinine clearance (ml/min/1.73 m²) 65.7 ± 28.4/63.2 ± 27.8/68.8 ± 25.3, respectively. Both doses of losartan significantly lowered blood pressure and proteinuria (p < 0.05 vs. baseline), and losartan 100 mg was more effective than 50 mg in reducing proteinuria (52.5 ± 29.0 vs. 40.5 ± 30.8%, respectively, p = 0.001). No differences in the antiproteinuric effect of losartan was observed among the ACE I/D genotype. Losartan 100 mg demonstrated a comparable degree of mean arterial pressure (mean ± SD, %) (II/ID/DD, 13.3 ± 7.6/10.8 ± 9.8/13.0 ± 11.6, respectively, p = NS) and proteinuria reduction (mean, 95% CI) among the three genotypes (51.4% (40.3-62.5%)/53.4% (45.5-61.4%)/51.4% (40.0-63.8%), respectively, p = NS). Conclusion: Our data suggest that losartan provides a similar short-term antiproteinuric response for all three genotypes of ACE I/D genotype in non-diabetic proteinuric chronic renal disease.