Effect of proteinuria reduction on prevention of focal glomerulosclerosis by angiotensin-converting enzyme inhibition is modifiable

Background. Proteinuria is associated with a progressive loss of renal func tion; we recently found that both intrarenal effects of proteinuria and the state of systemic nephrosis play an independent rule in proteinuria-induce d renal damage. Reduction of proteinuria is an important mechanism underlyi ng the renoprotective effect of angiotensin-converting enzyme inhibition (A CEI). Both the reduction of proteinuria and the attenuation of the systemic state of nephrosis may be involved in the renoprotection by ACEi. Methods. This article entails a post hoc analysis of a previous study on th e renoprotective effect of ACEi lisinopril in adriamycin nephrosis. It was attempted to modify therapeutic efficacy of ACEi by increasing lisinopril d ose and by dietary sodium restriction, respectively. In this analysis, we a imed to delineate the contribution of proteinuria reduction and the reducti on of other intermediate parameters such as hyperlipidemia and blood pressu re on the protection against focal glomerulosclerosis (FGS). Results. We found that in adriamycin nephrosis, ACEi significantly reduced proteinuria, lipids, and blood pressure and provided protection against FGS . Treatment modification by increasing the lisinopril dose resulted in a fu rther reduction of FGS without significant effects on intermediate paramete rs (proteinuria. hyperlipidemia, and blood pressure), whereas surprisingly, treatment modification by sodium restriction resulted in a further attenua tion of intermediate parameters, without additional protection against FGS. Conclusions. The renoprotective benefit of an obtained attenuation of inter mediate parameters is modified by Ether factors. Further optimization of re noprotective therapy requires identification of such factors and explicit c onsideration of therapeutic efficacy on intermediate parameters as well as hard end points.