Understanding phenotypic characteristics of the diabetic kidney is important for the development of therapies to prevent progression of diabetic nephropathy. In addition to glomerular hyperfiltration and kidney growth, major metabolic abnormalities characterize the diabetic kidney. Increased kidney oxygen consumption leads to cortical and medullary hypoxia in diabetes. Decreasing inspired oxygen to 10% reduces pO2, while oxygen consumption remains elevated, lactate increases, and redox potential decreases, but only in the diabetic kidney--a shift to Warburg metabolism.