The influence of ambient temperature on foot temperature in patients with diabetic foot ulceration

Background: Patients with diabetic neuropathy exhibit a higher foot temperature than those without neuropathy and they are at risk for foot ulceration. Ambient temperature and foot ulceration additionally influence foot temperature in such patients. The aim of the study was to assess the influence of ambient temperature on foot temperature in patients with an ulcer on one of the feet. Methods: Miniature temperature data loggers were used for the monitoring of foot skin and ambient temperature. Twenty patients with diabetic neuropathy and ten healthy subjects were monitored for about 24 h each. Results: The temperature of the foot with an ulcer correlates significantly with ambient temperature, with the slope of the regression line of 0.09. The temperature of the non-ulcerated foot also correlates significantly with ambient temperature, with the slope of 0.31, however the correlation coefficient and the slope are significantly higher than in the case of the foot with an ulcer. The difference of temperature of the foot with an ulcer and temperature of the foot without an ulcer correlates well with ambient temperature with the slope of -0.219. The temperatures of left and right feet were studied as a function of ambient temperature in healthy individuals and there were no statistically significant differences between correlation coefficients and slopes. Conclusions: It is apparent that ambient temperature influences foot temperature even during foot ulceration. Thus ambient temperature should be taken into consideration in any application when foot temperatures are important, especially in the prediction of diabetic foot ulceration. (C) 2014 Nalecz Institute of Biocybernetics and Biomedical Engineering. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.