6 Clinical Trials for Various Conditions
To highlight the importance of protein quality rather than the total protein content of a meal, the investigators will demonstrate that unlike high quality proteins, a single meal containing 30 g of an incomplete protein source does not stimulate skeletal muscle protein synthesis. Secondly, the investigators will directly challenge a prevalent, but untested, assertion that has the potential to negatively impact health. The goal is to demonstrate that complementary plant-proteins (i.e., two or more incomplete protein sources) must be consumed at the same meal to stimulate protein synthesis.
Warfighters often experience physical overload, as the uniform and associated gear that they carry burdens them with substantial loads. The loads increase energy expenditure to levels that exceed a Warfighter's typical energy intake. The typical assault load is approximately 25 kg, although loads as high as 55 kg are often carried, which when combined with extreme energy expenditures can degrade health and performance, and increase the risk of injury. Branched-chain amino acid (leucine) supplementation may confer protection against the negative effects of operational stress by stimulating muscle protein synthesis and reducing degradation. This study will determine if leucine-enriched nutrition supplementation confers protection against the negative consequences of sustained load carriage exercise, and explore the mechanisms by which leucine might impart protection.
The modern warfighter faces numerous physiological challenges including sleep deprivation, sustained intense physical activity, and caloric restriction, the combined effects of which may result in the loss of lean body mass and decreased physical performance. Dietary interventions may help preserve lean body mass and facilitate recovery from periods of intense physical demand. For example, dietary strategies that increase amino acid availability have been shown to stimulate protein synthesis in skeletal muscle following resistance exercise. Because military tasks also incorporate endurance exercise components, studies regarding the effects of increasing dietary amino acids following endurance exercise are warranted. The objectives of this study are to characterize the effect of endurance exercise on protein synthesis and breakdown as well as the ability of an essential amino acid supplement to influence skeletal muscle protein metabolism and its cellular and molecular regulation following endurance exercise.
This study is funded by the Moody Endowment. In this project, we will investigate the potential effect of skeletal muscle nitric oxide (NO) production on skeletal muscle anabolism, muscle strength, physical function, and body composition in older individuals. Further, we will determine whether augmentation of NO-mediated signaling reduces fatigue and fatigability.
Loss of muscle protein is generally a central component of weight loss in Chronic Obstructive Pulmonary Disease (COPD) patients. Gains in muscle mass are difficult to achieve in COPD unless specific metabolic abnormalities are targeted. The investigators recently observed that alterations in protein metabolism are present in normal weight COPD patients. Elevated levels of protein synthesis and breakdown rates were found in this COPD group indicating that alterations are already present before muscle wasting occurs. The investigators recently observed that in order to enhance protein anabolism, manipulation of the composition of proteins and amino acids in nutrition is required in normal-weight COPD. Intake of casein protein resulted into significant protein anabolism in these patients. The anabolic response to casein protein was even higher than after whey protein intake. A substantial number of COPD patients, underweight as well as normal weight to obese, is characterized by an increased inflammatory response. This group failed to respond to nutritional therapy. Previous experimental research and clinical studies in cachectic conditions (mostly malignancy) indicate that polyunsaturated fatty acids (PUFA) are able to attenuate protein degradation by improving the anabolic response to feeding and by decreasing the acute phase response. Eicosapentaenoic acid (EPA) (in combination with docosahexaenoic acid (DHA)) has been shown to effectively inhibit weight loss in several disease states, however weight and muscle mass gain was not present or minimal. Until now, limited research has been done examining muscle protein metabolism and the response to EPA and DHA supplementation in patients with COPD. It is the investigator's hypothesis that supplementation of 2g/day EPA+DHA in COPD patients during 4 consecutive weeks will increase the muscle anabolic response to a high quality protein supplement as compared to a placebo, and supplementation of 3.5g/day EPA+DHA will increase the anabolic response even further. In the present study both the acute and chronic effects of EPA+DHA versus a placebo on muscle and whole body protein metabolism will be examined. The principal endpoint will be the extent of stimulation of net fractional muscle protein synthesis as this is the principal mechanism by which the effect of EPA+DHA on muscle anabolism can be measured. The endpoint will be assessed by isotope methodology which is thought to be the reference method.
The objective of this study is to determine the effects of a single dose of testosterone undecanoate during and in recovery from simulated operational stress.