Diabetic peripheral neuropathy as measured using a point‐of‐care sural nerve conduction device is associated with a faster decline in renal function in patients with type 2 diabetes

Aims/Introduction Diabetic peripheral neuropathy (DPN) is a common complication of diabetes mellitus and may be linked to renal function decline. However, the prognostic value of point‐of‐care nerve conduction devices such as DPN‐Check® for renal outcomes remains unclear. Materials and Methods We conducted a single‐center retrospective observational study of 403 patients with diabetes (median follow‐up 2.9 years) at Tokyo Metropolitan Ohkubo Hospital. DPN was assessed by DPN‐Check® (amplitude [AMP] <5 μV or nerve conduction velocity [NCV] <42 m/s) and simplified diagnostic criteria (SDC). The primary outcome was annual eGFR decline, calculated by the linear least squares method; rapid decliners were defined as those with a decline ≥5 mL/min/1.73 m 2 /year. Multivariate linear and logistic regression analyses were performed to identify independent associations. Results Patients with DPN diagnosed with DPN‐Check® had a greater annual eGFR decline than those without (−2.26 vs. −0.81 mL/min/1.73 m 2 /year, P < 0.001), whereas DPN diagnosed with SDC showed no association. In multivariate analysis, DPN diagnosed with DPN‐Check® remained independently associated with faster eGFR decline (standardized β: −0.262, P < 0.001) and with rapid decliner status (odds ratio [OR]: 2.791, 95% confidence interval [CI]: 1.267–6.152, P = 0.011). Conclusions DPN diagnosed by DPN‐Check® was independently associated with accelerated renal function decline in patients with T2DM, even after adjusting for albuminuria. DPN‐Check® may help identify patients at high risk for end‐stage kidney disease and guide earlier intervention for both neuropathy and kidney disease.