2. Patients with diabetic nephropathy (history of type 1 or type 2 diabetes for > 7 years, no other cause for proteinuria listed in their medical chart). This is the definition used in most peer-reviewed trials44,45 of diabetic nephropathy. We do recognize that their proteinuria could be due to some other concomitant kidney disease but the only way to confirm that is to do a kidney biopsy which is not clinically justified.