Non-Invasive Assessment of Microcirculatory Dysfunction in Type 2 Diabetes Patients with and without Ulcers in Western Province of Saudi Arabia

Abstract

The present study aimes at comparing the predictive trends of transcutaneous oxygen pressure (PtcO2) and microcirculation in arbitrary perfusion unit measured at the tip of big toe along with Toe-Brachial Index (TBI) in normal subjects as well as age and sex matched type 2 diabetes mellitus(T2DM) patients with and without ulcers. Thirty healthy subjects along with 51 T2DM patients without ulcer and 40 T2DM patients with ulcer were included. Measurement site for PtcO2 and Laser Doppler (LD) was at the tip of big toe. LD and PtcO2 recordings were made before and after heat provocation and 100% normobaric oxygen challenge respectively. T2DM with ulcer group was subdivided into subgroups according to clinical outcomes: healed, unhealed and/or death cases. TBI was significantly lower (P=0.0001) in T2DM with ulcer compared with either healthy or T2DM without ulcer. All death cases only as a subgroup (n=10) too had significantly lower (P<0.05) TBI compared with healed cases (n=15). A %change from the base value of LD after heat provocation was significantly higher in healthy compared with both T2DM control (P=0.029) and T2DM patients with ulcers (P=0.011) while an opposite trend of significantly lower % change in PtcO2 was observed in healthy as compared with T2DM control (P=0.025) or with T2DM with ulcer (P=0.038). As compared to absolute values, a %change in LD and PtcO2 base values, upon heat provocation or oxygen challenge, unambiguously differentiate microcirculatory status of healthy and T2DM groups and that the LD-heat and TBI are good predictors of bad outcome (deaths/unhealing) in T2DM with ulcer patients.