Dysfunction of Nutritive Blood Flow as a Determinant of Anabolic Resistance With Age; the Role of Amino Acids in Modulating Muscle Metabolism (Ajinomoto1A)

University of Nottingham

Status: Unknown

Conditions: Old Age (Focus; Not a Recognized Condition)

Treatments: Dietary Supplement: 15g EAA Bolus supplemented with 3g Arginine; Dietary Supplement: 4 x 3.75g Mixed EAA Pulses; Dietary Supplement: 15g EAA bolus

Study type: Interventional

Funder types: Other

Identifiers

NCT01735539

UNottingham F/3/2009

Details and patient eligibility

About

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.

Full 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.

Enrollment: 40 estimated patients

Sex: Male

Ages: 18 to 75 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• age 65-75 or 18-28

Exclusion criteria

• BMI >30
• Diabetes
• Beta blocker or steroid use
• Established cerebrovascular, peripheral vascular or ischaemic heart disease.

Trial design

Primary purpose: Treatment

Allocation: Non-Randomized

Interventional model: Parallel Assignment

Masking: Double Blind

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40 participants in 5 patient groups

Old Bolus

Experimental group

Description:

15g EAA bolus

Treatment:

Dietary Supplement: 15g EAA bolus

Old Arginine

Experimental group

Description:

15g EAA Bolus supplemented with 3g Arginine

Treatment:

Dietary Supplement: 15g EAA Bolus supplemented with 3g Arginine

Young Bolus

Experimental group

Description:

15g EAA bolus

Treatment:

Dietary Supplement: 15g EAA bolus

Young Pulse

Experimental group

Description:

4 x 3.75g Mixed EAA Pulses

Treatment:

Dietary Supplement: 4 x 3.75g Mixed EAA Pulses

Old Pulse

Experimental group

Description:

4 x 3.75g Mixed EAA Pulses

Treatment:

Dietary Supplement: 4 x 3.75g Mixed EAA Pulses