Merchant ML et al. – The ability of microalbuminuria to predict early progressive renal function decline in type 1 diabetic patients has been questioned. To resolve this, the authors determined the plasma proteome differences between microalbuminuric patients with type 1 diabetes and stable renal function (controls) and patients at risk for early progressive renal function decline (cases) and asked whether these differences have value as surrogate biomarkers. The authors have identified plasma protein fragments, some of which have biological activity with moderate to strong correlation, with early progressive renal function decline in microalbuminuric patients with type 1 diabetes. Other peptides are candidates for validation as candidate biomarkers of diabetes–associated renal dysfunction.