Effects of Amino Acids on Regional Lipid Metabolism

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT01150188
Recruitment Status : Completed
First Posted : June 24, 2010
Last Update Posted : October 27, 2016
National Institute on Aging (NIA)
Information provided by (Responsible Party):
University of Arkansas

Brief Summary:
Elevated fat level in blood is a risk factor for coronary heart disease, a major cause of death in America. The overall goal of this project is to test a novel treatment using nutrient (amino acid) supplementation against this condition in men and women, and to understand how this treatment works.

Condition or disease Intervention/treatment Phase
Hypertriglyceridemia Dietary Supplement: Amino acids Dietary Supplement: Placebo Not Applicable

Detailed Description:

Coronary heart disease (CHD) remains the single largest killer of American men and women (45). Hyper¬triglyceridemia (elevated triglyceride [TG] concentration in the blood) has been shown to be a significant independent risk factor for CHD (7;8;25), accordingly, treatment for hypertriglyceridemia has been included in the Adult Treatment Panel III (ATP III) of the National Cholesterol Education Program (36). In a meta-analysis of 21 population-based prospective studies including a total of 65,863 men and 11,089 women, each increase of 89 mg/dl (1 mmol/l) in TG concentration was associated with a 32% increase in CHD risk in men and 76% increase in women (3). Thus, hypertriglyceridemia is an even stronger risk factor for CHD in women than in men.

The prevalence of hypertriglyceridemia is high. It is a common finding with aging, and is also associated with overweight, obesity, diabetes, and renal disease (39). With the aging of the US population and ongoing epidemics of obesity and type 2-diabetes, the number of individuals with conditions associated with elevated TG levels is likely to grow.

4.1.2 Effect of Amino Acids on Plasma Triglyceride Concentration In an effort to clarify the potential independent effect of protein on plasma and tissue lipids, we supplemented a normal weight-maintaining diet with a relatively small amount of amino acids (~90 kcal/day) between meals. We measured tissue lipids in addition to plasma lipids since the increase in insulin resistance with aging has been linked to increased fat accumulation in muscle and liver tissue (20;63). Also, it has repeatedly been shown that amino acid intake stimulates muscle protein synthesis and improves muscle protein net balance (86). Our hypothesis was that supplementation of the normal diet with a mixture of amino acids will reduce circulating and tissue TG concentrations and improve insulin sensitivity in elderly subjects with impaired glucose tolerance. Twelve impaired glucose tolerant elderly ingested 11 g of essential amino acids (EAA) + arginine twice a day for 16 weeks, after a 7 week control run in. Diet and activity were not otherwise modified. We found individuals consuming the EAA supplement had improved physical function. Further, these individuals had lower plasma and liver TG concentrations than before supplementation, and total cholesterol and VLDL-cholesterol concentrations were also lower after supplementations (12). In the present study, we will investigate this by supplementing the diet of older subjects shown to have hypertriglyceridemia.

Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 125 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary Purpose: Basic Science
Official Title: Effects of Amino Acids on Regional Lipid Metabolism
Study Start Date : June 2010
Actual Primary Completion Date : August 2016
Actual Study Completion Date : August 2016

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Triglycerides
U.S. FDA Resources

Arm Intervention/treatment
Active Comparator: Amino acids
Amino acid supplementation between meals for eight weeks
Dietary Supplement: Amino acids
11 g amino acids two times per day for eight weeks
Placebo Comparator: Placebo
Supplementation of placebo (inert components) between meals for eight weeks
Dietary Supplement: Placebo
Placebo of inert compounds, 11 g two times per day for eight weeks

Primary Outcome Measures :
  1. Very low density lipoprotein (VLDL) turnover [ Time Frame: Eight weeks ]
    Turnover rates of VLDL-triglycerides and VLDL-ApoB-100, including synthesis and breakdown rates, measured before and after eight weeks of amino acid supplementation

Secondary Outcome Measures :
  1. Fat oxidation [ Time Frame: 8 weeks ]
    Fat oxidation measured before and after eight weeks of amino acid supplementation

  2. Lipolysis [ Time Frame: 8 weeks ]
    Lipolysis measured before and after eight weeks of amino acid supplementation

  3. Triglyceride uptake in muscle and adipose tissue [ Time Frame: Eight weeks ]
    Triglyceride uptake in muscle and adipose tissue measured before and after eight weeks of amino acid supplementation

Information from the National Library of Medicine

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Ages Eligible for Study:   50 Years to 75 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Age 50-75 years.
  • Men and Women (Women postmenopausal).
  • Ability to sign informed consent, including ≥26 Mini-Mental State Exam.
  • Plasma triglyceride concentration between 130-500 mg/dl.

Exclusion Criteria:

  • Diabetes (plasma glucose: fasting ≥126 mg/dl or ≥200 mg/dl at 2 hr after 75 g glucose load).
  • On diabetes medication or lipid altering agents, including over the counter fish oil/omega 3 fatty acids.
  • Kidney/renal or liver disease.
  • Bleeding disorders or anemia.
  • Endocrine disease.
  • Positive hepatitis or HIV screens.
  • Alcohol abuse or drug abuse
  • Score of <26 on the Mini-Mental State Exam.
  • Allergy to iodine or fish products.
  • Subjects with cerebral aneurysm clips, internal transistorized devices (e.g., neural stimulators), or cardiac pacemakers.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT01150188

United States, Arkansas
University of Arkansas for Medical Science, Reynolds Aging Institute
Little Rock, Arkansas, United States, 72205
Sponsors and Collaborators
University of Arkansas
National Institute on Aging (NIA)
Principal Investigator: Elisabet Borsheim, PhD University of Arkansas

Responsible Party: University of Arkansas Identifier: NCT01150188     History of Changes
Other Study ID Numbers: 139210
1R01AG033761-01A1 ( U.S. NIH Grant/Contract )
First Posted: June 24, 2010    Key Record Dates
Last Update Posted: October 27, 2016
Last Verified: October 2016

Keywords provided by University of Arkansas:
lipid metabolism
very low density lipoproteins
amino acids
dietary supplements

Additional relevant MeSH terms:
Lipid Metabolism Disorders
Metabolic Diseases