Isolated and grouped relationships between type 2 diabetes and peripheral arterial disease on skin temperature in the foot plantar region

Abstract

The aim of the study was to verify relationships between isolated and grouped clinical conditions (Type 2 Diabetes Mellitus [T2DM] and Peripheral Arterial Disease [PAD]) with the skin temperature of the plantar region of the feet (Tskin_Feet). Twenty-four elderly women participated, divided into three groups: GT2DM + PAD (n = 8; 69.6 ± 8.0 years-old; 148 ± 5 cm; 63.8 ± 8.9 kg), GT2DM (n = 8, 69.3 ± 7.8 years-old, 151 ± 6 cm; 66.3 ± 10.8 kg), and control group (CG) (n = 8; 69.3 ± 6.6 years old; 148 ± 6 cm; 58.0 ± 5.3 kg). The T2DM was diagnosed based on HbA1C concentrations, and PAD was assessed using the Ankle-Brachial Index. Thermographic images were captured for both feet using the Flir thermal camera (model T420®) and analyzed using Flir Tools® software. The Inner canthus (IC) measurement was used as an indicator of core body temperature. Five regions of interest (ROIs) were determined for each image. The difference (Δ) between the temperature at the IC (average among right and left side) and of the each of the five ROIs in the plantar region (right foot and left foot) was calculated, where lower values indicated a closer proximity to the core body temperature. The one-way ANOVA was performed to verify differences between groups of clinical conditions. A significance level of 5% was assumed. The GT2DM group exhibited higher Tskin_Feet absolute values than the CG for all ROIs. However, just for ROI4 (hindfoot) of the right foot plantar was significant (p = 0.027). On the other hand, when analyzing the values difference between the average temperature at the IC of the temperature in the five evaluated ROIs on the right and left foot, the GT2DM group showed significantly lower values than the CG for for ROI 2 (forefoot) p = 0.0429 and ROI 4 (hindfoot) p = 0.009 on the right foot and for ROI 1 (forefoot) p = 0.0338; ROI 2 (forefoot) p = 0.0392 and ROI 5 (hindfoot) p = 0.0377 on the left foot. In conclusion, GT2DM presented a Tskin_Feet closer to the core temperature (IC) indicating a higher temperature. The presence of PAD appears to attenuate skin overheating.