Creatine Monohydrate Supplementation Effects on Oxidative Stress and Blood Flow in Older Adults with Overweight/Obesity

The incidence of cardiovascular disease (CVD) has risen to alarming levels such that in 2020 CVD accounted for over 19 million deaths. Risk factors for CVD are advanced age, excess body mass and adipose tissue, and the frequent consumption of high carbohydrate (HC) meals that induce hyperglycemia. One of the key contributing mechanisms to the development of CVD is the presence of reactive oxygen species (ROS). ROS are highly unstable molecules that when in excess, overpower the body's natural antioxidant defense system and induce a state of oxidative stress. A prominent source of ROS generation in the vasculature is derived from the enzymatic activity of nicotinamide adenine dinucleotide phosphate oxidases (NOX), a group of multi-subunit transmembrane proteins. Furthermore, with rates of CVD so high it is crucial to find novel interventions to reduce the risk of CVD. Creatine monohydrate (CM), a popular performance supplement, has shown promise in reducing ROS concentrations and enhancing blood flow. Therefore, the aim of the dissertation is twofold, first to determine the impact of NOX produced ROS on skeletal muscle microvascular blood flow (SMBF) in older individuals with overweight/obesity. Second, to determine the effect of five days of CM supplementation on ROS concentrations and SMBF at rest and in response to a HC meal in individuals with overweight/obesity. Nine individuals had two microdialysis probes placed (control (CON) and apocynin (APO): NOX inhibitor) in skeletal muscle to measure in vivo ROS (Hydrogen Peroxide (H2O2)) concentrations and SMBF (ethanol outflow/inflow ratio, inversely related to blood flow) at rest and four hours post-meal consumption. Procedures were performed both before (PRE) and after (POST) five days of CM supplementation and PL supplementation (20 g/day). APO perfusion locally into skeletal muscle via microdialysis served as a potent suppressant of NOX-produced H2O2 concentrations following the consumption of a HC meal. However, this did not affect SMBF, dialysate glucose, lactate, or glycerol concentrations at rest or following the consumption of a HC meal. Furthermore, five days of CM supplementation had no effect on in vivo H2O2 concentrations or SMBF. Five days of CM supplementation did not lower skeletal muscle dialysate lactate concentrations at rest or following the administration of a HC meal. These data suggest that CM supplementation may not act as an antioxidant, elicit changes to SMBF, or improve metabolism via lactate reductions at rest or following the consumption of a HC meal in older adults with overweight/obesity. However, longer clinical trials are warranted to fully assess the effect of NOX and CM supplementation and on oxidative stress, vascular health, and metabolism in older adults with overweight/obesity.

Grantor dc:publisher

Florida State University

Year dc:date

2024

Contributors dc:contributor

• Baker, Paul A. (author)
• Hickner, Robert C., 1962- (professor directing dissertation)
• Cao, Hongyuan (university representative)
• Ormsbee, Michael J. (committee member)
• La Favor, Justin (committee member)
• Watso, Joesph C. (committee member)
• Florida State University (degree granting institution)
• College of Education, Health, and Human Sciences (degree granting college)
• Department of Health, Nutrition, and Food Sciences (degree granting department)

• Nutrition

Language dc:language

English

Identifier

fsu:927829
iid: Baker_fsu_0071E_18662

OAI identifier oai:identifier

oai:diginole.lib.fsu.edu:fsu_927829