In this study, we simulated the natural pathogenesis of human obesity and prepared obese and diabetic rat models using a high-fat and high-glucose diet, respectively combined with STZ in order to observe the expression of GRP78 protein, a molecular chaperone of ERS, in each group of cochleae, and investigated the molecular mechanism of hyperlipidemia and diabetes on inner ear damage. Here, HSPA5 is linked to obesity due to melanocortin 4 receptor deficiency.