By multivariate analysis, diabetes was significantly associated with urinary Ang II levels in transplant subjects, consistent with intrarenal RAS activation in diabetes [28] . In this regard, although diabetic patients had significantly higher urinary ACE activity and ACE protein levels by immunoblot, this association was not confirmed in the multivariate analysis. Finally, although diabetics had higher urinary ACE2 activity and protein levels, there was no significant association between diabetes and urinary levels of Ang-(1-7) by multivariate analysis, suggesting that urinary Ang-(1-7) may be influenced by other factors. A potential limitation of the urinary angiotensin peptide measurements is that urine specimens were not treated with protease inhibitors, which could have affected the sensitivity for detecting differences. Interestingly, however, we did observe a significant correlation between urinary ACE2 activity and Ang-(1-7) levels.