Sudomotor Denervation Found in Diabetic Neuropathy

Sudomotor denervation has been demonstrated in individuals with diabetic neuropathy, and the sweat gland innervation index (SGII) correlates with glycated hemoglobin (HbA1c) levels, according to published research.

Kai-Ren Luo, of the National Taiwan University, and colleagues conducted a study involving 42 patients with diabetic neuropathy and 42 age- and sex-matched control subjects to elucidate the pathology of sudomotor innervation and its relationship with glycemic control. Skin biopsies of the distal leg were immunostained for nerve fibers, using antiprotein gene product 9.5, and counterstained for sweat glands using Congo red. A new computerized area-based morphometric system was used to quantify the SGII.

The researchers found that patients with diabetic neuropathy exhibited sudomotor denervation, manifested as depleted periglandular nerve fibers with lower SGII compared with control subjects. There was a significant association between SGII and HbA1c, and SGII was lower in those with anhidrosis of the feet versus those with normal sweating of the feet. Cardiac autonomic dysfunction, assessed by reduced heart rate variability, correlated with sudomotor denervation.

"This is the first study to document the correlation of HbA1c with the SGII, suggesting the potential influence of diabetes control on sweat gland innervation in type 2 diabetes," the authors write.