Peripheral nerve cross-sectional area (CSA) was larger in individuals with diabetes, with further enlargement observed in those with diabetic sensorimotor polyneuropathy (DSP). This systematic review and meta-analysis, published in Diabetes Research and Clinical Practice, evaluated 47 ultrasound-based studies, of which 41 were included in quantitative analyses. 

The study assessed CSA of peripheral nerves across upper and lower extremity sites in individuals with diabetes with and without DSP, compared with healthy controls. The primary outcome was the weighted inter-group mean difference in CSA across all reported anatomical locations.

Individuals with diabetes without DSP showed larger CSA values than healthy controls at 3 of 11 anatomical sites, all located in the lower extremity. Those with diabetes and DSP demonstrated increased CSA compared with controls at 9 of 14 sites, particularly at distal compression sites of the median and tibial nerves. Compared with individuals with diabetes without DSP, those with DSP had larger CSA values at 14 of 21 sites, with the greatest difference observed 4-5 cm proximal to the medial malleolus (pooled mean difference +5.26 mm²; 95% CI 0.94-9.57).

These findings indicate greater peripheral nerve enlargement in diabetes, with more pronounced changes in the presence of DSP, particularly at distal compression sites.