Association of serum adenosine deaminase level with nerve conduction velocity in type II diabetes patients

Introduction: Adenosine plays an important role in increasing glucose uptake into muscles. Adenosine deaminase (ADA) enzymes convert adenosine into inosine and 2′-deoxyinosine. Increased ADA activity leads to the reduction of adenosine, subsequently lowering glucose absorption in skeletal muscles. Uncontrolled diabetes tends to result in complications such as diabetic neuropathy.To investigate the association between serum ADA levels and lower limb nerve conduction velocity in individuals with type II diabetes mellitus. Methods: This study included 60 participants, with 30 patients in the diabetes group and the remaining 30 in the control group. Serum ADA levels were measured, and nerve conduction recordings were performed on the lower limb’s motor peroneal, tibial, and sensory sural nerves.  Results: In diabetes patients, lower limb sensory sural nerves, motor tibial, and peroneal nerves showed increased latency, reduced amplitude, and decreased nerve conduction velocity compared to the control group. ADA levels were found to be higher in diabetic patients than in the control group. A negative correlation was observed between sensory sural nerve conduction velocity and ADA levels, with females exhibiting more negative correlations than males. No association was found between motor peroneal and motor tibial nerve conduction parameters and ADA levels. Conclusion: Sensory nerves are affected much earlier than motor nerves under hyperglycemic conditions. Elevated ADA levels indicate reduced insulin sensitivity, and the depletion of adenosine contributes to nerve damage. ADA levels could be useful in diagnosing early peripheral nerve damage.