Oral and intravenous glucose administration elicit opposing microvascular blood flow responses in skeletal muscle of healthy people: role of incretins.

"This study was approved by the Deakin University Human Research Ethics Committee (2019‐062) and conformed to the standards set by the Declaration of Helsinki . All participants provided written informed consent. Participants were included in the study if they were aged between 18 and 50 years, were normal to overweight (BMI range: 18.5–30.0 kg/m 2 ) and normotensive (seated brachial blood pressure: <140/90 mmHg). Individuals were excluded if they were outside the age and BMI range, had a first degree relative or >1 grandparent with diagnosed type 2 diabetes, hypertensive (blood pressure: >140/90 mmHg), current smoker, pregnant or lactating, or had any personal history of cardiovascular disease, malignancy, diabetes, liver disease, pulmonary disease, arthritis or musculoskeletal disease. Based on an a priori sample size calculation, it was estimated that 13 participants would be required to detect a two‐fold difference in MBF between the oral glucose tolerance test (OGTT) and intravenous glucose tolerance test (IVGTT) (SD = 115%, effect size = 0.87, α = 0.05, power = 80%) based on previous work (Russell et al . 2018 ). Ten participants completed the study between September 2019 and March 2020 prior to COVID‐19‐related clinic closures. Competing interests None."

"Funding L.P. is supported by a NHMRC & National Heart Foundation Fellowship (APP1157930). This work was supported by the Diabetes Australia Research Program (Y21G‐KESM) and the Deakin University Institute for Physical Activity and Nutrition (2020‐2021) seed funds."