Vascular and neurological mechanisms are both likely to be involved in foot ulcer. We recently reported on the hand an original transient pressure-induced vasodilation (PIV) during a 5 mmHg/min increase of pressure strain using laser Doppler flowmetry. This physiological response to non noxious external local pressure strain is a widely protective cutaneous mechanism. The impairment of PIV in diabetic subjects may be relevant to the high prevalence of foot ulcer that occurs in these individuals. The aim of the project is to analyse the different physiopathological processes involved in PIV impairment in diabetic subjects as compared to matched controls.

The whole study is a prospective observational study of diabetic type 1 and type 2 subjects focusing on the various physical, physiopathological or pharmacological mechanisms that may interfere with the normal response of the cutaneous microcirculation.The study is currently conducted under various parallel groups of patients and control subjects matched on age and sexe. Techniques used for the study are only non-invasive investigations such as iontophoresis with laser doppler flowmetry, clinical and paraclinical non-invasive investigation of peripheral neuropathy, ultrasound imaging of peripheral arteries.

Inclusion Criteria:

• Diabetes

Exclusion Criteria:

• Non diabetic neuropathy
• Peripheral arterial disease
• pregnancy