Serum uric acid as a biological marker for assessment of progression of glycemic status and polyneuropathy in experimentally induced type 2 diabetic rats

Background: Screening for laboratory indicators and modifiable risk factors for diabetic polyneuropathy (DPN) is crucial for early detection and development of novel treatments. This study investigated the possible correlation of serum uric acid to the progression of glycemic status and polyneuropathy in experimentally induced type 2 diabetic rats. Methods: Sixty rats were divided into non-diabetic, diabetic 4-week non-treated, diabetic 8-week non-treated, diabetic 4-week metformin-treated, diabetic 8-week metformin-treated. Rats were evaluated for glycemic state, serum uric acid, lipid profile, inflammatory and oxidative stress parameters. Hot plate test, sciatic nerve conduction speed, and sciatic nerve histopathological changes were assessed. Results: Four weeks after high-fat diet (HFD) and low dose of streptozotocin (STZ) injection, rats showed significant elevation in blood glucose, HbA1c and HOMA-IR, uric acid, malondialdehyde, TNF-α, IL-6, thermal hyperalgesia and significant reduction of nerve conduction speed and total antioxidant capacity associated with significant changes in lipid profile and histopathological structure of sciatic nerve. These changes were more prominent after 8 weeks of STZ injection than in 4-week diabetic-non-treated group. Metformin treatment significantly improved all parameters, meanwhile the improvement was more prominent in 8-week than 4-week group. Conclusion: Serum uric acid can be taken as a useful biological marker for assessment of progression of diabetic status and polyneuropathy in type 2 diabetes.