After obtaining informed consent, a spot urine sample was collected from each subject, and a blood sample was drawn for measurement of serum creatinine (Cr) and determination of estimated glomerular filtration rate (eGFR), using the Modification of Diet in Renal Disease (MDRD) calculation [15] . Demographic information was obtained via interview with the subject and/or from the hospital chart. For transplant recipients, a diagnosis of diabetes mellitus and the primary renal diagnoses were obtained directly from survey of the hospital chart.