Statistical analysis Mann-Whitney and chi-square (or Fisher) tests were used in the univariate analysis. For the analysis of the effect of enalapril on proteinuria during the first 2 years of treatment we have used a non-parametric repeated measures analysis (Friedmann´s test). We have analyzed the main predictive variables of CKD progression, by considering a creatinine clearance below 60 ml/min/1.73m2 as an outcome.