Note: Urine Plasma Amino Acid Testing is more accurate than Plasma Amino Acid Testing – plasma testing is done if 24 hour urine testing is difficult.
- Assessment of amino acids and diagnostic metabolites.
- Patient has dietary issues and problems with protein digestion
- Suspected protein deficiency or wasting disease
- Amino acid analyses aid in the diagnosis of: dietary protein adequacy and balance, gastrointestinal dysfunctions, forms of protein intolerance, nutritional deficiencies (vitamins, minerals), renal and hepatic dysfunction, psychiatric abnormalities, susceptibility to inflammatory response and oxidative stress, reduced detoxification capacity, susceptibility to occlusive arterial disease and many inherent disorders in amino acid metabolism.
- Measures protein balance through amino acid concentrations.
Assessing for Degenerative Diseases
As the old saying goes “you are what you eat” however, for some individuals the issue is not what they eat but what they digest. Many individuals have “hidden” impairments in amino acid metabolism that are problematic and often go undiagnosed. These impairments may or may not be expressed as specific symptoms. They may silently increase susceptibility to a degenerative disease or they may be associated with, but not causative for, a disease. Because of the wealth of information provided, it is suggested that a complete amino acid analysis be performed whenever a thorough nutritional and metabolic workup is called for.
Measuring Nutrient Adequacy:
Amino acid analysis provides fundamental information about nutrient adequacy: the quality and quantity of dietary protein, digestive disorders, and vitamin and mineral deficiencies (particularly folic acid, B12 , B6 metabolism, zinc and magnesium). In addition amino acid analysis provides important diagnostic information about hepatic and renal function, availability of precursors of neurotransmitters, detoxification capacity, susceptibility to occlusive arterial disease (homocystine), and many inherent disorders in amino acid metabolism.
Which Type of Analysis: Urine or Plasma?
The 24-hour urine amino acid analysis has the highest probability of detecting abnormalities if renal function is normal. The 24-hour test indicates what is high and low over the course of a day, reflects blood and tissue amino acid pools, and is not affected by circadian rhythm. Healthy kidneys efficiently conserve essential amino acids. Therefore, urine levels of amino acids decrease first and tend to give an earlier indication of inadequacy than do plasma levels.
A first morning void urine amino acid analysis, with results normalized per gram creatinine, provides an alternative when a complete 24-hour collection is not a viable option. The first morning void analysis is excellent for identification of marked abnormalities, particularly with respect to gastrointestinal health, inherited disorders in amino acid metabolism, and renal function, and can be used for protein challenge testing.
Plasma amino acid analysis measures what is being transported at the time of sampling. Abnormalities are deduced by comparison of measured levels with an established reference range. (The specimen should be collected after an overnight fast to reduce the influence of dietary protein). Plasma analysis is an excellent compromise if urine collection is difficult.