Ceramide species Kidney Ceramides Plasma Ceramides Pearson r p value Pearson r p value Cer C14:0 -0.4683 0.0783 0.3666 0.1790 Cer C16:0 -0.2507 0.3674 0.6493 0.0088 Cer C18:0 -0.2829 0.3068 0.4896 0.0640 Cer C20:0 0.0308 0.9134 0.6646 0.0069 Cer C22:0 -0.0926 0.7429 -0.3509 0.1997 Cer C24:0 -0.3457 0.2069 -0.5806 0.0232 Cer C24:1 -0.4160 0.1230 0.1945 0.4874 Glu-Cer C16:0 -0.8523 <0.0001 -0.2294 0.4109 Glu-Cer C18:0 -0.5305 0.0419 0.9215 <0.0001

Table 2: Correlation analysis of ceramide levels and kidney PAS staining Pearson correlation analysis of Periodic Acid-Schiff (PAS) staining in kidney sections with kidney ceramide levels or plasma ceramide levels from non-diabetic control (db/+) and diabetic (db/db) mice. Significance was defined as p < 0.05.