4 Clinical Trials for Various Conditions
Test the theory that abnormalities in the large blood vessels that deliver blood to your leg and the very small blood vessels in your leg's muscles (invisible to the eye) work together to worsen your leg function and walking.
Elevated circulating levels of certain amino acids (the building blocks of protein) are strongly associated with insulin resistance. This study will investigate the metabolism of these amino acids in individuals with normal glucose metabolism compared to overweight or obese pre-diabetic individuals. The purpose of this study is to determine how elevated levels of the branched-chain amino acids may contribute to the development of insulin resistance and ultimately diabetes. An additional purpose is to determine whether exercise or gastric bypass (GBP) surgery intervention can correct aberrations in branched-chain amino acid metabolism as insulin sensitivity improves. This information will be used to further our understanding of the development of insulin resistance and type 2 diabetes in at-risk populations and potentially improve clinical treatment of such conditions.
Branched-chain amino acids (BCAAs) are essential nutrients that the body obtains from proteins found in food, especially meat, diary products, and legumes. Data from rodent studies suggest that reduction of dietary BCAAs will promote fat mass loss and improved control of blood glucose. The purpose of this study is to test if reduction of dietary BCAAs without reducing calorie intake will lead to similar metabolic benefits in humans. Here the investigators test the feasibility of reducing dietary BCAAs using BCAA-free meal replacement beverages for two months.
Dietary protein is digested in the stomach and intestines to smaller peptides and 20 individual amino acids which, when absorbed by the gut into circulation and taken up by skeletal muscle, help stimulate muscle protein synthesis (MPS). Amino acids also provide the building blocks for muscle proteins that contribute to lean mass gains and increased strength following resistance exercise. Therefore, strategies to efficiently maximize amino acid exposure without overconsumption are warranted. Oral enzyme supplementation is a candidate approach to optimize amino acid absorption from dietary protein and protein supplements. Microbial proteases, approved for dietary supplement use, can theoretically speed up the conversion of protein and peptides to amino acids. Protease supplements have been marketed to promote muscle strength by optimizing amino acid absorption, however the clinical evidence is limited. This work will support that ingestion of protease supplements with a meal can allow individuals to more efficiently increase amino acid levels from a given amount of dietary protein.