Effects of Nutritional Supplementation (Product 4808) on Acute Skeletal Muscle Protein Synthesis in Cancer Patients

Overview

The purpose of the study is to compare two different nutritional supplements with respect to their effect on building muscle, and to determine the factors that control the rate at which muscle tissue can be produced in subjects with cancer. After three days of receiving all meals from the Reynolds Institute on Aging in order to stabilize their diet, subjects will then return to the Institute to perform a single day study, where they will be given one of two supplements to drink. Blood will be taken from a catheter placed in one of their arms and three muscle biopsy samples will be taken from a leg. Subjects will have x-ray evidence of cancer and be 40 years of age or older in order to participate. It is the hypothesis that a nutritional supplement with a high amount of protein and containing leucine will target the metabolism problems in cancer patients.

Muscle protein is generally diminished in cancer patients, with an effect on outcome. Research has shown that recurrence in treated patients is directly related to the extent of muscle loss. The effects of nutritional supplements; however, is still controversial. Anorexia due to metabolic changes in cancer patients can lead to reduced food intake and supplementation orally has often failed to show weight gain in these patients. These observations have led to the conclusion that even though food intake should be increased in order to gain lean body mass, this is difficult to achieve unless specific metabolic abnormalities are targeted. This study is a comparison of two supplements on muscle protein synthesis. Approximately 40 patients with radiographic evidence of cancer, ages 40 and older will be enrolled. Participation will require a screening procedure, including a history of medical problems and a physical exam, which may include blood testing for HIV or hepatitis as well as possibly for various basic diagnostic parameters. There may also be a urine-based drug screen or pregnancy test (if female). Participants should be in general good health and not have a variety of exclusion criteria. There will be three days of diet stabilization, during which all meals will come from the Reynolds Institute of Aging. If subjects cannot comply with the diet, dietary recording will be substituted. Following these three days, there will be one day of main study activities. There will be catheters placed in both arms and blood samples will be taken from one of these. Stable amino acid isotopes will be infused into the bloodstream through the other. There will be three muscle biopsies taken from the thigh muscle throughout the day. Two doses of a nutritional supplements will be consumed 20 minutes apart during the main study day.