In the present study, we found that type 2 diabetes significantly down-regulated the expression of renal Nrf-2 and the downstream targets SOD-1, HO-1 and NQO-1, which were remarkably reversed by exposure to LDR, especially at 50 or 75 mGy for both 4 and 8 weeks. Here, HMOX1 is linked to type 2 diabetes mellitus.