Transient receptor potential vanilloid 1 (TRPV1) receptor stimulation by topical capsaicin for the functional assessment of diabetic neuropathy leading to diabetic foot disease

Objectives: As neuropathy predominates vasculopathy, predicting functional deterioration of autonomic neurovascular dysfunction is essential to reduce diabetic foot ulcers. The present study has evaluated the possibility of stimulating the TRPV1 receptors of the small fibres using topical capsaicin to assess diabetic neuropathy in the dorsum of the foot functionally. Materials and Methods: A prospective cross-sectional study was carried out on ten healthy volunteers and 20 diabetic patients after receiving ethical approval. The subjects underwent vascular Doppler analysis after giving written agreement followed by monofilament testing. Then, topical capsaicin was applied to measure the local autonomic neurovascular reaction. With the use of an infrared-based digital instrument that was specially created, the vasodilation and proportional increase in temperature brought on by the application of capsaicin were quantified. Results: The percentage change in the local temperature in the control group varied from 0.478 to 3.315 compared to the diabetic group, which varied from 1.862 to ?3.932. There is a statistically significant difference in the mean of the two groups (P = 0.006) at a 95% confidence interval. Conclusion: This study suggests that TRPV1 receptor stimulation using capsaicin and resultant vasodilation monitored by the increase in local temperature can be used as a quantitative predictor of the early small fibre neuropathy in Distal Symmetric Polyneuropathy before the patient ends up with diabetic foot ulcer.

Gene microarray analysis of peripheral blood mononuclear cells in type 2 diabetes patients with distal symmetric polyneuropathy / 第二军医大学学报

Objective:To screen for the differentially expressed genes in peripheral blood mononuclear cells(PBMCs) from type 2 diabetes patients with distal symmetric polyneuropathy(DSPN) by gene microarray.Methods: A 5 075 gene cDNA microarray was used to examine gene expression in PBMCs of 2 type 2 diabetes patients with DSPN(group 1),2 type 2 diabetes patients without DSPN(group 2),and 2 age-and sex-matched controls(control group).The differentially expressed genes were identified and subjected to real-time RT-PCR analysis.Results: Twenty-two genes were found to be differentially expressed,including cell metabolism and signal transduction genes,oncogenes and anti-oncogenes,DNA synthesis and repair genes,ion channel and transport protein genes,DNA-binding,transcription and transcription factor genes,and cytoskeleton genes.There were 4 genes up-regulated and 18 down-regulated.Real-time RT-PCR results of AK1 and FBXO7 were consistent with that of microarray analysis.Conclusion: Microarray expression profile of PBMC in type 2 diabetes patients with DSPN is differential.DSPN may be involved in cell metabolism,signal transduction,DNA synthesis,etc.