Sensitivity Alterations Assessed with Monofilament: No Association with Temperature in the Soles of Diabetic Patients

Background: Previous studies have suggested that neuropathy is linked to changes in temperature in the soles of diabetic patients and rats. However, primary care in Mexico is limited. This study explores whether thermography can detect temperature changes in areas with sensitivity alterations (assessed using monofilament testing). Objectives: This study aims to compare the temperature of the soles of diabetic patients with tactile sensitivity alterations against those without such alterations. Additionally, we compared the temperature between non-sensitive and sensitive sites on the feet and finally found a regression model. Methods: A case-control study was conducted involving 116 feet with sensitivity alterations and 116 feet without alterations by the Semmes-Weinstein monofilament (SWM). We performed a comparative cross-sectional analysis of sensitive and non-sensitive sites' temperatures and a logistic regression. Sensitivity was evaluated using the SWM at nine sites. Sensitivity alteration was defined as the inability to detect all tested sites on the sole with SWM. Additionally, pallesthesia was assessed using a 128 Hz tuning fork. The temperature of the soles was measured using a FLIR model T865 thermal imaging camera, capturing minimum, maximum, and mean temperatures in degrees Celsius (°C) across the same nine sites assessed for sensitivity. Results: No significant differences were observed in temperature between cases and controls or between sensitive and non-sensitive sites in patients with diabetes. Logistic regression resulted in a model that included only creatinine. However, the temperature was not associated with the model. Conclusions: The study found no association between sensitivity alterations and temperature in the sole in patients with type 2 diabetes, as determined through SWM testing.