Antiproteinuric effect of the calcium channel blocker cilnidipine added to renin-angiotensin inhibition in hypertensive patients with chronic renal disease

Impact of renin-angiotensin system inhibition on microalbuminuria in type 2 diabetes: a post hoc analysis of the Shiga Microalbuminuria Reduction Trial (SMART)

The Shiga Microalbuminuria Reduction Trial (SMART) showed the advantage of ARB over CCB beyond the blood pressure (BP)-lowering effect in reducing microalbuminuria. To further assess the impact of BP control or renin-angiotensin system inhibition on microalbuminuria, the SMART patients were re-analyzed. Hypertensive patients with type 2 diabetes and microalbuminuria were randomly assigned to valsartan or amlodipine treatment groups for 24 weeks. Target blood pressure was set at <130/80 mmHg. Changes in the urinary albumin creatinine ratio (ACR) from baseline were assessed in the valsartan monotherapy (VM) group (n=33), the amlodipine monotherapy (AM) group (n=36), the concomitant valsartan and angiotensin-converting enzyme inhibitor group (VA) (n=33), and the concomitant amlodipine and angiotensin-converting enzyme inhibitor (AA) group (n=38). At the end of the study, mean BP was not different among the four treatment groups. The changes in ACR from baseline to the end of the treatment period in VM, AM, VA, and AA were -36%, +30%, -26%, and +8%, respectively. The dissociation between the anti-albuminuric and antihypertensive effects of valsartan or amlodipine was observed in the respective monotherapy groups. In the AA group, however, a significant positive relationship was found between the changes in ACR and those in systolic BP. In conclusion, RAS inhibitors may be necessary in order for calcium channel blockers to have an effect on microalbuminuria. Therefore, RAS inhibitors are first-line drugs for hypertensive patients with type 2 diabetes and microalbuminuria.

Reversal of proteinuric renal disease and the emerging role of endothelin

Proteinuria is a major long-term clinical consequence of diabetes and hypertension, conditions that lead to progressive loss of functional renal tissue and, ultimately, end-stage renal disease. Proteinuria is also a strong predictor of cardiovascular events. Convincing preclinical and clinical evidence exists that proteinuria and the underlying glomerulosclerosis are reversible processes. This Review outlines the mechanisms involved in the development of glomerulosclerosis--particularly those responsible for podocyte injury--with an emphasis on the potential capacity of endothelin receptor blockade to reverse this process. There is strong evidence that endothelin-1, a peptide with growth-promoting and vasoconstricting properties, has a central role in the pathogenesis of proteinuria and glomerulosclerosis, which is mediated via activation of the ET(A) receptor. Several antiproteinuric drugs, including angiotensin-converting-enzyme inhibitors, angiotensin receptor antagonists, statins and certain calcium channel blockers, inhibit the formation of endothelin-1. Preclinical studies have demonstrated that endothelin receptor antagonists can reverse proteinuric renal disease and glomerulosclerosis, and preliminary studies in humans with renal disease have shown that these drugs have remarkable antiproteinuric effects that are additive to those of standard antiproteinuric therapy. Additional clinical studies are needed.