Skin denervation in type 2 diabetes: correlations with diabetic duration and functional impairments

Sensory neuropathy is a prominent component of diabetic neuropathy. It is not entirely clear how diabetes influences skin innervation, and whether these changes are correlated with clinical signs and laboratory findings. To investigate these issues, we performed skin biopsies on the distal leg of 38 consecutive type 2 diabetic patients with sensory symptoms in lower limbs (25 males and 13 females, aged 56.2 ± 9.4 years) and analysed the correlations of intraepidermal nerve fibre (IENF) densities in skin with glycaemic status (duration of diabetes, HbA1C, and fasting and post‐prandial glucose levels), and functional parameters of small fibres (warm and cold thresholds) and large fibres (vibratory threshold and parameters of nerve conduction studies). Clinically, 23 patients (60.5%) had signs of small‐fibre impairment, and 19 patients (50.0%) had signs of large‐fibre impairment. IENF densities were much lower in diabetic patients than in age‐ and gender‐matched controls (1.794 ± 2.120 versus 9.359 ± 3.466 fibres/mm, P