Dysfunction of Nutritive Blood Flow as a Determinant of Anabolic Resistance With Age; the Role of Amino Acids in Modulating Muscle Metabolism (Ajinomoto1A)
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Purpose
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.
| Condition | Intervention |
|---|---|
|
Old Age (Focus; Not a Recognized Condition) |
Dietary Supplement: 15g EAA bolus Dietary Supplement: 4 x 3.75g Mixed EAA Pulses Dietary Supplement: 15g EAA Bolus supplemented with 3g Arginine |
| Study Type: | Interventional |
| Study Design: | Allocation: Non-Randomized Intervention Model: Parallel Assignment Masking: Double Blind (Subject, Investigator) Primary Purpose: Treatment |
| Official Title: | 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. |
- Muscle Protein Synthesis (FSR, fractional synthetic rate, %/hr) [ Time Frame: Across 6hr study ] [ Designated as safety issue: No ]We measure FSR when fasted and again 0-90, 90-180 and 180-240 post feed.
- Muscle Protein Breakdown (MPB) [ Time Frame: Across 6hr study ] [ Designated as safety issue: No ]MBP is measured during fasting and 0-90, 90-180 and 180-240mins post feed.
- Whole leg blood flow [ Time Frame: Across a 6hr study ] [ Designated as safety issue: No ]We measure common femoral blood flow by doppler ultrasound when fasted and again 0-90, 90-180 and 180-240 post feed.
- Muscle Microvascular Blood flow [ Time Frame: Across a 6hr study ] [ Designated as safety issue: No ]We measure muscle microvascular flow using contrast enhanced ultrasound when fasted and again 0-90, 90-180 and 180-240 post feed.
| Estimated Enrollment: | 40 |
| Study Start Date: | December 2011 |
| Estimated Study Completion Date: | May 2013 |
| Primary Completion Date: | May 2013 (Final data collection date for primary outcome measure) |
| Arms | Assigned Interventions |
|---|---|
|
Experimental: Old Bolus
15g EAA bolus
|
Dietary Supplement: 15g EAA bolus
Oral; in aqueous solution
Other Name: Mixed Essential Amino Acids
|
|
Experimental: Old Arginine
15g EAA Bolus supplemented with 3g Arginine
|
Dietary Supplement: 15g EAA Bolus supplemented with 3g Arginine
Oral; in aqueous solution
|
|
Experimental: Young Bolus
15g EAA bolus
|
Dietary Supplement: 15g EAA bolus
Oral; in aqueous solution
Other Name: Mixed Essential Amino Acids
|
|
Experimental: Young Pulse
4 x 3.75g Mixed EAA Pulses
|
Dietary Supplement: 4 x 3.75g Mixed EAA Pulses
Oral; in aqueous solution
|
|
Experimental: Old Pulse
4 x 3.75g Mixed EAA Pulses
|
Dietary Supplement: 4 x 3.75g Mixed EAA Pulses
Oral; in aqueous solution
|
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.
Eligibility| Ages Eligible for Study: | 18 Years to 75 Years |
| Genders Eligible for Study: | Male |
| Accepts Healthy Volunteers: | Yes |
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.
Contacts and Locations| United Kingdom | |
| University of Nottingham School of Graduate Entry Medicine and Health | Recruiting |
| Derby, United Kingdom, DE23 6PF | |
| Contact: Kyle Mitchell, MB BChir mzxwm@nottingham.ac.uk | |
| Principal Investigator: Philip J Atherton, PhD | |
| Sub-Investigator: John P Williams, PhD MB BS | |
| Principal Investigator: | Philip J Atherton, PhD | University of Nottingham |
More Information
No publications provided
| Responsible Party: | University of Nottingham |
| ClinicalTrials.gov Identifier: | NCT01735539 History of Changes |
| Other Study ID Numbers: | UNottingham F/3/2009 |
| Study First Received: | November 22, 2012 |
| Last Updated: | May 9, 2013 |
| Health Authority: | UK: University of Nottingham Medical School Research Ethics Committee UK: University of Nottingham HTA Compliance Group |
Keywords provided by University of Nottingham:
|
old age sarcopenia essential amino acid arginine |
contrast enhanced ultrasound muscle microcirculation muscle protein synthesis |
ClinicalTrials.gov processed this record on May 22, 2013