Habitual Protein Intake and Muscle Protein Synthesis

Sarcopenia Clinical Trial

— Pro-Hab  

Official title:

The Impact of Habitual Dietary Protein Intake on the Anabolic Response in Elderly Men

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01986842
• Other study ID #: METC 13-3-050
• Status: Completed
• Phase: N/A
• First received: November 12, 2013
• Last updated: November 27, 2014
• Start date: January 2014
• Est. completion date: July 2014

Study information

• Verified date: November 2014
• Source: Maastricht University Medical Center
• Contact: n/a
• Is FDA regulated: No
• Health authority: Netherlands: The Central Committee on Research Involving Human Subjects (CCMO)
• Study type: Interventional

Clinical Trial Summary

Protein intake stimulates muscle protein synthesis. From the standpoint of maintaining skeletal muscle mass with aging, it is important to optimize the adaptive response to food intake. However, a paucity of information is available describing the effects of habitual dietary protein intake (i.e. either high or low amounts of dietary protein consumed on a regular basis), on the subsequent meal-induced stimulation of muscle protein synthesis. An adaptation to a diet of several days or weeks may involve splanchnic and/or skeletal muscle adaptations that may further enhance, or decrease, the amino acid sensitivity of muscle protein synthesis after protein ingestion.

The aim of this study is to investigate the effect of a habitual (14 days) high protein diet when compared with low protein diet on digestion and absorption kinetics and the subsequent muscle protein synthetic response to dietary protein ingestion.

Description:

During the adult life skeletal muscle mass remains fairly constant until the fourth or fifth decade. Then, the slow process of sarcopenia (the age-related loss of muscle mass) is believed to begin. The maintenance of skeletal muscle mass is regulated by a balance between the opposing processes of muscle protein synthesis and muscle protein breakdown. Food intake, dietary protein in particular, stimulates muscle protein synthesis and allows net muscle protein accretion throughout the day, which allows the normal maintenance of muscle mass in healthy individuals. Many studies have described the postprandial muscle protein synthetic response to protein intake and/or physical activity, and these acute findings have led to recommendations for protein intake for both athletes wishing to gain muscle mass as well as patients and elderly individuals to help them maintaining muscle mass. However, translating the acute findings from a single meal to long-term recommendations is perhaps premature, since scientists know very little with regard to how previous consumed meals affect the anabolic responsiveness to subsequent food intake. A characteristic of the adaptation to habitual high or low protein intake is thought to be associated with a change in the amplitude of diurnal cycle of whole body proteins. If this speculation is accurate, it implies that the muscle protein synthetic responses to feeding (differences between fasting and feeding muscle protein synthesis rates) are adapting to differing habitual protein intake, which may reduce (or enhance) the anabolic responsiveness to protein intake.

To gain a more complete scientific understanding, it is necessary to examine whether an adaptation does in fact occur after habitual high or low amounts of protein intake with regard to the anabolic response to subsequent protein intake. In the present investigation, we wish to investigate the impact of the habitual consumption of either high or low protein diets for 14 days on the anabolic responsiveness to a protein meal in healthy elderly. Previous work has determined that whole body adaptations to protein intake occur after >10 days. Collectively, our findings will be valuable to maximize the skeletal muscle adaptive response to food intake and, ultimately, to develop nutritional strategies for maintenance or enhancement of skeletal muscle mass in elderly men.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 24
• Est. completion date: July 2014
• Est. primary completion date: July 2014
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Male
• Age group: 55 Years to 75 Years

Eligibility

Inclusion Criteria:

• Healthy males

• Age between 55 and 75 y

• BMI between 18.5 and 30 kg/m2

Exclusion Criteria:

• Lactose intolerance

• Smoking and alcohol abuse

• Diabetes

• Diagnosed GI tract diseases

• Arthritic conditions

• A history of neuromuscular problems

• Any medications known to affect protein metabolism (i.e. corticosteroids, non-steroidal anti-inflammatories, or prescription strength acne medications).

• Use of anticoagulants

• Participation in exercise program

• Hypertension, high blood pressure that is above 140/90 mmHg.

Study Design

Allocation: Randomized, Endpoint Classification: Bio-availability Study, Intervention Model: Parallel Assignment, Masking: Single Blind (Subject), Primary Purpose: Prevention

Related Conditions & MeSH terms

• Sarcopenia

Intervention

Dietary Supplement:
• Protein diet
Subjects will receive either a low protein or a high protein diet for 14 days. High protein will be realized with protein supplements.

Locations

Country	Name	City	State
Netherlands	Maastricht University	Maastricht	Limburg

Sponsors (1)

Lead Sponsor	Collaborator
Maastricht University Medical Center

Country where clinical trial is conducted

Netherlands, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Other	Plasma insulin		0-5 h postprandial period	No
Other	Plasma amino acid concentrations		0-5 h postprandial period	No
Other	Whole-body protein metabolism	Protein metabolism (breakdown, synthesis, oxidation, net balance)	0-5 h postprandial period	No
Primary	Muscle protein synthesis rates	Change in MPS rates during the postprandial phase when compared with the basal phase	0-5 h postprandial period	No
Secondary	Digestion/Absorption kinetics	Difference in digestion of the intrinsically labeled protein after a 14-day period of high vs. low protein diet	0-5 h postprandial period	No