Assessing endothelial dysfunction in adolescents and young adults with type 1 diabetes mellitus using a non-invasive heat stimulus

BackgroundMicrovascular dysfunction is a key event in the development of atherosclerosis, which predates the clinical manifestations of vascular disease including stroke and myocardial infarction. Dysfunction of the microvasculature can be measured as a decreased microperfusion in response to heat. ObjectiveWe sought to evaluate the microvasculature using heat among adolescents and young adults with type 1 diabetes (T1D) compared to healthy non-diabetic controls. We hypothesized that youth with T1D would have impaired microvascular function measured as decreased perfusion. MethodsWe studied 181 adolescents and young adults with T1D and 96 age-, race-, and sex-matched healthy controls (mean age 19yr). Patients were seen at an in-person study visit where demographics, anthropometrics, and laboratory data was obtained. Skin microvascular perfusion was measured on the volvar surface of the right forearm using a standard laser flow Doppler. Measurements were taken at baseline and after heating to 44 degrees C. ResultsYouth with T1D had decreased microvascular perfusion as measured by lower percent change of perfusion units (1870945 vs. 2539 +/- 1255, p<0.01) and percent change in area under the curve (1870 +/- 945 vs. 2539 +/- 1255, p<0.01) compared to controls. Glycosylated hemoglobin A1c (HbA1c) was found to be an independent determinant of microvascular function (p<0.05). Conclusions Adolescents and young adults with T1D have evidence of microvascular dysfunction that can be detected using heat, a non-invasive physiologic stimulus. HbA1c appears to play an independent role in determining microvascular perfusion suggesting tight glycemic control is probably important for the development of vascular disease.