The use of near-infrared spectroscopy for microvascular function assessment in healthy and with obesity individuals during normo- and hyperglycemia

Date
2019-09-19
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Vascular function has been shown to be an important predictor for cardiovascular disease (CVD). Among others, postprandial hyperglycemia has been shown to be a risk factor for CVD that is associated with impaired vascular function. Among others, obesity is a comorbidity associated with vascular dysfunction. In addition to the detrimental effects of obesity per se on the vasculature, obesity is also linked to impairments in glucose uptake/metabolism by the skeletal muscle, which further expose these individuals to the deleterious effects of glucose on the vascular tree. Thus, the overall objectives of the current thesis were to: i) assess changes in lower limb microvascular responsiveness induced by hyperglycemia in lean and obese individuals by using the near-infrared spectroscopy (NIRS) combined with vascular occlusion test (VOT) technique (NIRS-VOT); ii) use NIRS-VOT to compare differences in lower limb microvascular responsiveness during normoglycemia and hyperglycemia in lean and obese individuals; iii) investigate upper and lower limbs microvascular function and oxidative metabolism responses to glucose ingestion in participants with obesity compared to their healthy lean counterparts; iv) investigate the relationship between changes in upstream brachial artery flow-mediated dilation (FMD) and NIRS-VOT-derived assessment of forearm microvascular function induced by glucose ingestion in these individuals. The main findings of the present thesis were that NIRS-VOT detected hyperglycemia and obesity-related differences in microvascular responsiveness. Additionally, although no differences in the forearm microvascular responses to glucose ingestion were found between these two groups, obese individuals had impaired brachial FMD during hyperglycemia. The findings also demonstrated a blunted leg muscle oxidative metabolism response to glucose ingestion in obese individuals. The current thesis highlights the importance of assessing limb and muscle specific effects of hyperglycemia and obesity.
Description
Keywords
NIRS, obesity, vascular function
Citation
Nogueira Soares, R. (2019). The use of near-infrared spectroscopy for microvascular function assessment in healthy and with obesity individuals during normo- and hyperglycemia (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.