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Determination of Protein Requirements in Elderly Female Subjects >75 Yrs Old

This study has been completed.
Canadian Institutes of Health Research (CIHR)
Information provided by (Responsible Party):
Dr. Paul Pencharz, The Hospital for Sick Children Identifier:
First received: May 22, 2012
Last updated: August 16, 2013
Last verified: August 2013

Minimal data are available on protein requirements throughout the lifespan. Currently available recommendations are based on nitrogen balance data. The limitations of the nitrogen balance method have been well described. Importantly, nitrogen balanced underestimates requirements.

The current DRI requirement for healthy adult males is based on the reanalysis of the nitrogen balance date from Young and Scrimshaw. This data was reanalyzed statistically by Rand et al. and he concluded that the protein requirement of healthy adults was 0.65 and 0.83 (mean and RDA) g/kg/day of good quality protein. Using IAAO, the investigators group estimated the protein requirement of young men (mean age 27 years) to be 0.93 and 1.2 g/kg/day (mean and RDA).

Currently there are no studies on protein requirement in the elderly. In a recent nutrition survey conducted by NHANES, the authors concluded that adults between the ages of 51 - 70 years old consumed an average on 1.0 g/kg/day (ideal body weight) of protein which represents about 15 % of calories. Depending on the calculations used for ideal body weight some older adults could be getting higher or lower than requirement. There is no scientifically derived protein estimate for older adults. Therefore there is a need to measurer protein requirement in that population.

The goal of this study therefore is to measure the protein requirement of female elderly subjects >75 years using the IAAO technique.

Condition Intervention Phase
Healthy Females
Protein Requirement
Dietary Supplement: Protein intake.
Early Phase 1

Study Type: Interventional
Study Design: Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Treatment
Official Title: Use of Indicator Amino Acid Oxidation Technique to Determine Protein Requirement of Elderly Female Subjects >75 Years Old

Further study details as provided by The Hospital for Sick Children:

Primary Outcome Measures:
  • 13CO2 Production [ Time Frame: Study Day 3 ]
    Urine and breath samples will be collected on day 3 of the experiment to determine the rate of production

Enrollment: 14
Study Start Date: March 2012
Study Completion Date: December 2012
Primary Completion Date: December 2012 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Protein Intakes
subjects will recieve differnt levels of protein intakes varying from 0.2 to2.0g/kg/day.
Dietary Supplement: Protein intake.
protein intakes will be varied at 0.2, 0.5, 0.7, 0.9, 1.0, 1.2, 1.5, 1.8 and 2.0g/kg/day


Ages Eligible for Study:   76 Years to 90 Years   (Senior)
Sexes Eligible for Study:   Female
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  1. Healthy elderly females >75 years
  2. Willingness to participate in the study
  3. Females without a chronic disease or acute illness that could affect protein and AA metabolism eg, diabetes, cancer, liver or kidney disease, HIV, acute cold or flu, hypo or hyperthyroidism, rheumatoid arthritis treated with anti-inflammatory medications.
  4. Females with hypertension if well controlled by medications -

Exclusion Criteria:

  1. Presence of disease known to affect protein and AA requirement and synthesis like diabetes, cancer, liver o kidney disease, HIV, acute cold or flu, hypo or hyperthyroidism, rheumatoid arthritis treated with anti-inflammatory medications.
  2. On medications known to affect protein and amino acid metabolism like e.g. steroids.
  3. Significant weight loss during the past month.
  4. Individual on weight reducing diets.
  5. Inability to tolerate the diet or unwilling to have blood drawn from a venous access for the purposes of the study.
  6. Significant coffee consumption of more than 2 cups/day (400 mg of caffeine/day)
  7. Significant Alcohol consumption of more than one drink/day ( 1 beer, ½ glass of wine) -
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Please refer to this study by its identifier: NCT01604980

Canada, Ontario
The Hospital for Sick Children
Toronto, Ontario, Canada, M5G1X8
Sponsors and Collaborators
The Hospital for Sick Children
Canadian Institutes of Health Research (CIHR)
Principal Investigator: Paul Pencharz, MD The Hospital for Sick Children
  More Information

Publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: Dr. Paul Pencharz, Senior Scientist, The Research Institute, Hospital for Sick Children, The Hospital for Sick Children Identifier: NCT01604980     History of Changes
Other Study ID Numbers: 0019850580-B
Study First Received: May 22, 2012
Last Updated: August 16, 2013 processed this record on May 24, 2017