NCT01735539

Dysfunction of Nutritive Blood Flow as a Determinant of Anabolic Resistance With Age; the Role of Amino Acids in Modulating Muscle Metabolism

Dysfunction of Nutritive Blood Flow as a Determinant of Anabolic Resistance in Older People; The Role of Essential Amino Acids in Modulating Muscle Protein Metabolism; Bolus vs. Pulse Feeding Strategies and the Ability of Arginine to Rejuvenate Microvascular Responsiveness.

• Status: Unknown
• Phase: N/A
• Study type: Interventional
• Enrollment: 40 (estimated)
• Sponsor: University of Nottingham · Academic / Other
• Sex: Male
• Age: 18 Years – 75 Years
• Healthy volunteers: Accepted

Summary

The investigators plan to measure changes in muscle protein metabolism in response to feeding, comparing between a single large essential amino acid (EAA) feed (the normal building blocks of protein) and the provision of the same dose in 4 smaller feeds at 45min intervals. The investigators will perform this study in healthy older (65-75y) and younger (18-28) men. The investigators will also explore how feeding affects muscle blood flow as this is important in the delivery of the nutrients we eat to the muscle where they are used. The investigators plan to supplement the feed with arginine, a safe and widely found non-essential amino acid, to explore if this can improve muscle blood flow.

Detailed description

We will provide a 15g mixed essential amino acid feed or 4 x 3.75g. There is sexual dimorphism thus initially we will just recruit males. Powering calculations dictate n=8 in each group. We will use well established stable isotope tracer techniques (with 13C6 Phenylalanine) to measure muscle protein synthesis and breakdown by Gas Chromatography - combustion - isotope ratio mass spectroscopy. We will measure leg blood flow by phase shift Doppler and muscle microvascular flow by contrast enhanced ultrasound.

Conditions

• Old Age (Focus; Not a Recognized Condition)

Interventions

Type	Name	Description
DIETARY_SUPPLEMENT	15g EAA bolus	Oral; in aqueous solution
DIETARY_SUPPLEMENT	4 x 3.75g Mixed EAA Pulses	Oral; in aqueous solution
DIETARY_SUPPLEMENT	15g EAA Bolus supplemented with 3g Arginine	Oral; in aqueous solution

Timeline

• Start date: 2011-12-01
• Primary completion: 2014-01-01
• Completion: 2014-01-01
• First posted: 2012-11-28
• Last updated: 2014-01-17

Locations

1 site across 1 country: United Kingdom