Temperature as a Causative Factor in Diabetic Foot Ulcers: A Call to Revisit Ulceration Pathomechanics.

BACKGROUND: Diabetic foot ulcers (DFUs) are a major burden to patients and to the health-care systems of many countries. To prevent or treat ulcers more effectively, predictive biomarkers are needed. We examined temperature as a biomarker and as a causative factor in ulcer development. METHODS: Thirty-seven individuals with diabetes were enrolled in this observational case-control study: nine with diabetic neuropathy and ulcer history (DFU), 14 with diabetic neuropathy (DN), and 14 nonneuropathic control participants (DC). Resting barefoot plantar temperatures were recorded using an infrared thermal camera. Mean temperatures were determined in four anatomical regions-hallux and medial, central, and lateral forefoot-and separate linear models with specified contrasts among the DFU, DN, and DC groups were set to reveal mean differences for each foot region while controlling for group characteristics. RESULTS: The mean temperature reading in each foot region was higher than 30.0°C in the DFU and DN groups and lower than 30.0°C in the DC group. Mean differences were greatest between the DFU and DC groups, ranging from 3.2°C in the medial forefoot to 4.9°C in the hallux. CONCLUSIONS: Increased plantar temperatures in individuals with a history of ulcers may include acute temperature increases from plantar stresses, chronic inflammation from prolonged stresses, and impairment in temperature regulation from autonomic neuropathy. Diabetic foot temperatures, particularly in patients with previous ulcers, may easily reach hazard thresholds indicated by previous pressure ulcer studies. The results necessitate further exploration of temperature in the diabetic foot and how it may contribute to ulceration.

Dobutamine Cardiolite(®) stress testing with low-level treadmill exercise demonstrates improved image quality, less medication and fewer patient side effects.

Some form of exercise is helpful to achieve target heart rate (THR) in patients undergoing dobutamine Technetium-99 Sestamibi (Cardiolite(®)) stress tests. The outcomes of low-level exercise (slow treadmill walking) and isometric exercises to achieve THR during dobutamine Cardiolite(®) stress tests have not been examined. The purpose of this study was to determine if patients who walked on a treadmill during their dobutamine Cardiolite(®) stress test had better outcomes than those who used isometric exercises. The outcomes measured were the amount of dobutamine and atropine sulfate (atropine) used, duration of dobutamine infusion and quality of cardiac images. A convenience sample of 30 patients per group who required a dobutamine Cardiolite® stress test was recruited from April to September, 2008. Descriptive statistics were reported for each group. The subjects who walked on the treadmill required a lower dose of dobutamine (P = 0.028) and a decreased time of dobutamine infusion (P = 0.031) to achieve their target heart rate. Heart-to-liver ratio results (P = 0.08) and image quality (P < 0.0001) were better with the subjects who walked on the treadmill. No difference in atropine usage was found in either group. These outcomes suggest that the patient who walked on a treadmill during the dobutamine Cardiolite(®) stress test achieved the target heart rate faster, required less dobutamine and had better image quality than those who performed isometric exercises.