AMP Lab News

2021 Michael L. Pollock Student Scholarship, Gail E. Butterfield Nutritional Registrational Award

Mary Remchak

Mary-Margaret Remchak, a doctoral student in the AMP lab, was recently awarded the 2021 Michael L. Pollock Student Scholarship for Clinical Research as well as the Gail E. Butterfield Nutritional Registrational Award through the American College of Sports Medicine. The title of her work is Altered TCA cycle flux parallels insulin resistance and metabolic inflexibility in late chronotypes with obesity. Co-authors were: Dr. Emily M. Heiston, Ms. Anna Ballantyne, Ms. Brielle L. Dotson, Mr. Nathan R. Stewart, Dr. Andrea Spaeth, and Dr. Steven K. Malin.

 

Individuals often identify as being a “morning” or “evening” person. While this reflects generally when they may feel most productive, some research has suggested whether this identification (known as early and late chronotype) is linked to chronic disease. In fact, “evening” people have been associated with higher risks of obesity, type 2 diabetes and cardiovascular disease. The reason for this is unclear, but it has been suggested that alterations in metabolism may exist. The present work highlights that late chronotypes are more insulin resistant and do not use/store glucose as much as their early chronotype counterparts. Further, the findings showcase that there may be alterations in the TCA cycle, which is an important component of our mitochondria and energy production capabilities. The findings highlight additional work is needed to understand how to best prescribe lifestyle treatments for people with different chronotypes to mitigate chronic disease risk.

Integrative Physiology of Exercise: team recognized for excellence

Emily Heistonn
The 2020 Integrative Physiology of Exercise conference was held between November 9th to the 13th. Dr. Emily Heiston, a current post-doctoral fellow at Virginia Commonwealth University and former alumna of the AMP lab, was recognized for excellence in research. This work was part of her dissertation entitled: A single bout of exercise improves vascular insulin sensitivity in adults with obesity. The co-authors were Ms. Anna Ballantyne, as well as Drs. Zhenqi Liu, Sibylle Kranz and Steven Malin.

It’s known that exercise training reduces type 2 diabetes and cardiovascular disease risk. A single bout of exercise is also recognized to raise metabolic insulin sensitivity (i.e. insulin promotes muscle glucose uptake). However, little is known about how exercise impacts the ability of insulin to regulate vascular blood flow. The intent of this study was to tease out if a single bout of exercise can raise metabolic vs. vascular insulin sensitivity. This has public health relevance for targeting blood vessel health and glucose control.

People with obesity who were considered at risk for chronic disease were recruited. Participants performed a rest period (control) and supervised exercise session the night before measurements of metabolic insulin sensitivity as well as assessment of large and small blood vessel blood flow. Aerobic fitness was also measured to improve accuracy at which exercise was prescribed (70% of VO2max and 400 kcals). The results highlight that 1 exercise bout improved not only metabolic insulin sensitivity but also large and small blood vessel responses to insulin. Importantly, it was the increase in small blood vessel function that related to improved ability of the body to take up glucose and store it for energy. These findings improve understandings of how exercise works to combat chronic disease, Currently, the lab is conducting follow up studies to address additional means by which a single bout of exercise impacts vascular insulin sensitivity.

Kinesiology and Health student, Nathan Stewart, wins MARC-ACSM Award!


Nathan StewartThe Mid-Atlantic Regional Chapter of the American College of Sports Medicine (MARC-ACSM) held its 43rd annual meeting on Friday, November 6, 2020. Nathan Stewart, a 2nd year Master’s Student in the Kinesiology and Applied Physiology Graduate program within the Department of Kinesiology and Health, was awarded 1st place in the Master’s Student Competition. His work was entitled: Nocturnal Blood Pressure Dipping Relates to Insulin Sensitivity but not Vascular Function in Metabolic Syndrome. The co-authors were Dr. Emily Heiston, Ms. Stephanie Miller and Dr. Steven Malin.

The overall purpose was to better understand mechanisms that control blood pressure regulation in adults with obesity. While most are familiar with having their blood pressure taken when visiting the doctor’s office during the daytime, less are aware of what happens to their blood pressure at night or while they sleep. This is clinically important since blood pressure reductions while asleep, compared to daytime, is an independent factor promoting cardiovascular health. To understand better how blood pressure “dips” at night, people with obesity and metabolic syndrome were recruited. All participants underwent a series of tests that included measuring: aerobic fitness, body fatness, blood lipids and glucose, endothelial function, metabolic insulin sensitivity as well as 24-hour blood pressure. The results overall suggest that metabolic insulin sensitivity is an important piece to regulating nocturnal blood pressure. While these are preliminary findings, this work may lead to improved understandings for public health recommendations on how to maximize blood pressure treatment. Additional work is underway to confirm and address control of blood pressure in the department.