Upstroke Time Measured by Photoplethysmography

Peripherial arterial disease (PAD) and diabetes are major public health issues. In 2020, according to the latest epidemiological data, it is estimated that there will be more than one million patients with PAD and more than 3.5 million diabetic patients in France. In the diabetic patient, screening for PAD is carried out by calculating the Toe-Brachial pressure index (TBi), a technique that remains time-consuming and technically demanding, which limits its use for clinical routine screening. A new photoplethysmographic method (PPG) makes possible to determine the quality of peripheral perfusion thanks to the automatic computation of the upstroke time (TMS in ms). This method appears to be a promising, inexpensive, faster and easier technical alternative to improve the dissemination of the vascular screening in diabetics. To date, no prospective study has established a relationship between the measurement of upstroke time using the PPG method and TBi in a specific diabetic population.We will perform a two-centre prospective study (Nice University Hospital and Antibes Hospital) comparing the two techniques. The main objective of our study will compare the values of the upstroke time obtained by a PPG method and the TBi in a population of diabetic patients. The secondary objectives will be to compare the TBi values to the ratio of the TMS measurements at the toe to the reference TMS measured at the hand and to determine the sensitivity-specificity of the TMS measured by PPG compared to the TBi in the detection of a significant PAD in diabetics.