Wavelet-analysis ofskintemperature oscillations duringlocal heatingfor revealing endothelial dysfunction

abstract Article history:Accepted 17 October 2014Available online 27 October 2014Keywords:Endothelial dysfunctionSkin blood flowSkin temperature fluctuationsLocal heating testWavelet analysisType 2 diabetes Skin microvessels have proven to be a model to investigate the mechanisms of vascular disease; in particular,endothelial dysfunction. To analyze skin blood flow, high-resolution thermometry can be used because low-amplitude skin temperature oscillations are caused by changes in the tone of skin vessels. The aim of our studywas to test the possibilities of wavelet analysis of skin temperature (WAST) for the diagnosis of impairedregulation of microvascular tone in patients with type 2 diabetes. A local heating functional test was used forthe assessment of microvascular tone regulation. A control group consisted of healthy male and femalevolunteers (n = 5 each), aged 39.1 ± 5.3 years. A group of patients with type 2 diabetes comprised thirteenpeople, seven men and six women, aged 36 to 51 years old (43.2 ± 3.4 years). The diagnosis of diabetes wasmade according to the criteria of the World Health Organization (WHO). The mean disease duration was7.36 ± 0.88 years. Skin temperature oscillations, reflecting intrinsic myogenic activity (0.05–0.14 Hz), neuro-genic factors (0.02–0.05 Hz) and endothelial activity (0.0095–0.02 Hz) increase greatly during local heating forhealthy subjects. In the group of patients with type 2 diabetes, no statistically significant differences in theamplitudes in the endothelial range were observed. Relative changes in the oscillation amplitudes in patientswith type 2 diabetes were markedly lower compared to the control group. The latter indicates that the WASTmethodenablesassessmentofthestateofvasculartoneandtheeffectsofmechanismsresponsibleforregulationof blood flow in the microvasculature.© 2014 Elsevier Inc. All rights reserved.