Correlation between kidney and peripheral nerve functions in Type 2 diabetes

Background: Although greater impairments in nerve functions parameters are most likely to occur with a lower kidney function, there is a paucity of information on the relationship between the kidney and peripheral nerve functions parameters in Type 2 diabetes. Aim: To address the impact of peripheral nerve functions in Type 2 diabetes patients in different stages of chronic kidney diseases (CKD). Design: This prospective study enrolled 238 patients with Type 2 diabetes at a tertiary medical center. Method: We designed composite amplitude scores of nerve conductions (CAS) as a measure of severity of peripheral neuropathy (PN), and used estimated glomerular filtration rate (eGFR) and urine albumin-creatinine ratio (UACR) parameters to stage CKD in Type 2 diabetes patients. The intrapersonal mean, standard deviation and coefficient of variation of eGFR for 238 patients were obtained in the 3 years prior to the study. Results: The patients who had lower eGFR and higher UACR were older, with longer diabetes duration, a greater percentage of retinopathy and PN and higher CAS. Multiple linear regression analysis revealed that diabetes duration and eGFR were independently associated with CAS, and a cut-off value of eGFR in the presence of PN was 65.3 ml/min/1.73 m². Conclusion: We observed a close relationship between the severity of kidney and peripheral nerve function in patients with diabetes. If a patient's eGFR value is below 65.3 ml/min/1.73 m² or the UACR value is above 98.6 mg/dl, caution is needed with the presence of PN even in diabetic patients who are asymptomatic.