Personal
Professional
Research
Personal Professional Research Sign Up Login Pro Login
Research Isoleucine
Amino Acid Analysis Quest Diagnostics

Isoleucine

Optimal Result: 34 - 98 umol/L.

Branched Chain Amino Acids (Isoleucine, Leucine, Valine) are the three branched chain amino acids (BCAAs). Branched chain amino acids (BCAA) are essential amino acids and must be obtained from the diet (mainly meat, grains, and dairy).

Not only do the BCAAs account for almost 50% of muscle protein, but they have many metabolic functions.

BCAAs act as substrates for protein synthesis, energy production, neurotransmitter production, glucose metabolism, and the immune response. They are also involved in stimulation of albumin and glycogen synthesis, improvement of insulin resistance, inhibition of free radical production, and hepatocyte apoptosis with liver regeneration.

Unlike most amino acids, the initial step of BCAA metabolism does not take place in the liver. After dietary intake, BCAAs remain in circulation and are taken up by skeletal muscle, the heart, kidney, diaphragm, and adipose tissue for immediate metabolism. BCAAs are transaminated into α-keto acids and used within the tissues or released into circulation. The liver and other organs can then further catabolize these α-keto acids. The complete oxidation of valine yields succinyl CoA, and leucine and isoleucine produce acetyl CoA for use in the citric acid cycle. Isoleucine also produces propionyl CoA and succinyl CoA.

Skeletal muscle is a major site of BCAA utilization. During exercise, catabolism of the BCAAs is elevated; β-aminoisobutyric acid (β-AIB) is a metabolite of valine released during exercise. There is much published literature on the use of BCAAs for muscle protein synthesis, however it’s been shown that BCAA supplementation alone does not enhance muscle protein synthesis better than the consumption of a complete, high quality food protein containing the full spectrum of essential amino acids. 

Of the three BCAA, leucine may have the most immediate impact. Leucine is one of the few amino acids that is completely oxidized in the muscle for energy, generating more ATP molecules than glucose. Additionally, leucine can be used to synthesize fatty acids in adipose tissue, and generates HMG CoA, an intermediate in the synthesis of cholesterol.

Leucine also stimulates insulin secretion and promotes protein synthesis in the liver, muscle, and skin. BCAAs, grouped in patterns and as single biomarkers, have been studied as predictors of obesity, insulin resistance, type 2 diabetes, metabolic syndrome, and cardiovascular disease outcomes.

References:

- Gorska-Warsewicz H, Laskowski W, Kulykovets O, Kudlinska Chylak A, Czeczotko M, Rejman K. Food Products as Sources of Protein and Amino Acids-The Case of Poland. Nutrients. 2018;10(12):1977.

- Santos CS, Nascimento FEL. Isolated branched-chain amino acid intake and muscle protein synthesis in humans: a biochemical review. Einstein. 2019;17(3):eRB4898.

- Grüngreiff K. Branched amino acids and zinc in the nutrition of liver cirrhosis. J Clin Exp Hepatol. 2018;8(4):480.

- Holecek M. Branched-chain amino acids in health and disease: metabolism, alterations in blood plasma, and as supplements. Nutr Metab. 2018;15(1):33.

- Gropper S SJ, Groff J. Adv Nutr Human Metab. 5th ed. Belmont, CA: Wadsworth, Cengage Learning; 2009.

- Roberts LD, Bostrom P, O'Sullivan JF, et al. betaAminoisobutyric acid induces browning of white fat and hepatic beta-oxidation and is inversely correlated with cardiometabolic risk factors. Cell Metab. 2014;19(1):96-108.

- Mero A. Leucine supplementation and intensive training. Sports Med. 1999;27(6):347-358.

- Nie C, He T, Zhang W, Zhang G, Ma X. Branched Chain Amino Acids: Beyond Nutrition Metabolism. Int J Mol Sci. 2018;19(4).

- Ntzouvani A, Nomikos T, Panagiotakos D, et al. Amino acid profile and metabolic syndrome in a male Mediterranean population: A cross-sectional study. Nutr Metab Cardiovasc Dis. 2017;27(11):1021-1030.

- Yennawar N, Dunbar J, Conway M, Hutson S, Farber G. The structure of human mitochondrial branched-chain aminotransferase. Biol Crystallog. 2001;57(Pt 4):506-515.

- Duran M, Wadman SK. Thiamine-responsive inborn errors of metabolism. J Inher Metab Dis. 1985;8 Suppl 1:70-75.

- Chuang DT, Ku LS, Cox RP. Thiamin-responsive maplesyrup-urine disease: decreased affinity of the mutant branched-chain alpha-keto acid dehydrogenase for alphaketoisovalerate and thiamin pyrophosphate. Proc Nat Acad Sci USA. 1982;79(10):3300-3304.

- Fernhoff PM, Lubitz D, Danner DJ, et al. Thiamine response in maple syrup urine disease. Ped Res. 1985;19(10):1011-1016.

- Solmonson A, DeBerardinis RJ. Lipoic acid metabolism and mitochondrial redox regulation. J Biol Chem. 2018;293(20):7522-7530.

- Jurgens P, Schwartau M, Doehn M. [Disorders of amino acid metabolism in a patient with identified thiamine deficiency]. Infusionstherapie klinische Ernahrung. 1982;9(6):312-316.

- Brunetti-Pierri N, Lanpher B, Erez A, et al. Phenylbutyrate therapy for maple syrup urine disease. Human Mol Gen. 2011;20(4):631-640.

- Girish BN, Rajesh G, Vaidyanathan K, Balakrishnan V. Alterations in plasma amino acid levels in chronic pancreatitis. JOP : J Pancreas. 2011;12(1):11-18.

- Shaw S, Lieber CS. Plasma amino acids in the alcoholic: nutritional aspects. Alc Clin Exp Reds. 1983;7(1):22-27.

- Kawaguchi T, Nagao Y, Abe K, et al. Effects of branched-chain amino acids and zinc-enriched nutrients on prognosticators in HCV-infected patients: a multicenter randomized controlled trial. Molec Med Rep. 2015;11(3):2159-2166.

- Park YK, Linkswiler H. Effect of vitamin B6 depletion in adult man on the plasma concentration and the urinary excretion of free amino acids. JNutr. 1971;101(2):185-191.

- Vannucchi H, Moreno FS, Amarante AR, de Oliveira JE, Marchini JS. Plasma amino acid patterns in alcoholic pellagra patients. Alcohol Alcoholism. 1991;26(4):431-436.

What does it mean if your Isoleucine result is too high?

High protein intake may elevate BCAAs. In the catabolism of BCAAs, branched chain aminotransferase and branched chain alpha ketoacid dehydrogenase complex (BCKDC) require several cofactors such as vitamin B6, vitamin B1, and lipoic acid. Therefore, functional need for these cofactors may contribute to high levels of BCAAs.

BCAAs can be elevated due to a rare inborn error of metabolism. Maple Syrup Urine Disease is an inherited disorder of branched chain amino acid metabolism due to deficiency of the BCKDC complex.

What does it mean if your Isoleucine result is too low?

Low levels of essential BCAA may indicate a poor-quality diet, or maldigestion due to deficient digestive peptidase activity or pancreatic dysfunction.

Low levels of leucine can be seen after significant aerobic exercise or strength training.

Supplementation with zinc, vitamin B3, and vitamin B6, has improved outcomes in various conditions where low levels of BCAA’s have been associated.

Frequently asked questions

Healthmatters is a highly-personalized health dashboard.

Instead of searching for your lab results in different places or tracking them down from different providers, Healthmatters houses, organizes, and interprets them all in one central location.

With a Healthmatters account, you can dive into the details of each biomarker and gain insights into the meaning behind your medical test data, anytime, anywhere.

For our professional users, Healthmatters provides intuitive tools that not only streamline analysis but also save valuable time when delving into your client's lab report history.

Healthmatters.io personal account provides in-depth research on 4000+ biomarkers, including information and suggestions for test panels such as, but not limited to:

  • The GI Effects® Comprehensive Stool Profile,
  • GI-MAP,
  • The NutrEval FMV®,
  • The ION Profile,
  • Amino Acids Profile,
  • Dried Urine Test for Comprehensive Hormones (DUTCH),
  • Organic Acids Test,
  • Organix Comprehensive Profile,
  • Toxic Metals,
  • Complete Blood Count (CBC),
  • Metabolic panel,
  • Thyroid panel,
  • Lipid Panel,
  • Urinalysis,
  • And many, many more.

You can combine all test reports inside your Healthmatters account and keep them in one place. It gives you an excellent overview of all your health data. Once you retest, you can add new results and compare them.

If you are still determining whether Healthmatters support your lab results, the rule is that if you can test it, you can upload it to Healthmatters.

While we work with many popular labs, we welcome reports from lots of other places too.

It's as simple as this: if you can get a test done, you can upload it to Healthmatters and we can interpret results from any lab out there. If laboratories can analyze it, we can interpret it.

If you’re on the hunt for a specific biomarker, contact us and we'll add it to our database. Anything from blood, urine, saliva, or stool can be uploaded, understood, and tracked with your Healthmatters account.

There are two ways to add your test reports to your Healthmatters account. One option is to input the data using the data entry forms. The other method is to utilize our "Data entry service."

Our data entry forms offer an easy, fast, and free way for you to input the reports yourself. Self-entry allows you to add an unlimited number of reports at no cost. We make the self-entry process user-friendly, providing dozens of templates that pre-populate the most popular laboratory panels and offering instant feedback on entered values.

For those who prefer assistance, we offer a "Data entry service" to help you input your data. Simply attach an image or file of your lab test results, and a qualified team member from our data entry team will add the results for you.

We support various file types, including PDFs, JPGs, or Excel. This service is particularly useful if you have many reports to upload or if you're too busy to handle the data entry yourself.

Our special data entry service makes it easy to add your results to your private dashboard. Just attach an image or a file of your lab test results, and our skilled data entry team will do the work for you. It's all done by humans, ensuring that your data is entered accurately and with personal care for each client.

Depending on your account, the data entry service can be included for free or come at an additional cost of $15 per report.

For users on the Complete monthly plan, the first report is entered free of charge, and each additional report incurs a fee of $15.

Unlimited account holders enjoy the entry of ten reports without charge. Subsequent reports are subject to a $15 fee per report.

Additionally, users on the Complete plan can upgrade to a yearly subscription from the account settings. The annual subscription includes a data entry service for five reports.

The Unlimited plan is a one-time purchase for $250, and it covers your account for a lifetime with no additional payments.

For the Complete plan, the cost is $15 per month. You have the flexibility to cancel it anytime through your account settings, ensuring no further payments. To avoid charges, remember to cancel at least a day before the renewal date. Once canceled, the subscription remains active until the end of the current billing cycle.

Additionally, you can upgrade to the yearly Advanced plan from within your account. The annual cost is $79, and it comes with a data entry service for five reports.

You can always upgrade to a lifetime version with a prorated price from a monthly or yearly subscription.

Simply log in and navigate to your account settings to cancel your subscription. Scroll down to locate the 'Cancel' button at the bottom of the page. Ensure you cancel at least one day before the renewal date to prevent any charges. Once cancellation is requested, the subscription remains active until the conclusion of the current billing cycle.

Our goal has been to make your Healthmatters account as intuitive as possible.

We’ve crafted multiple ways for you to navigate your data, whether you're glancing at a single report or delving into your historical test reports.

1. Graph View:

Dive into a visual journey with our biomarker graphs, showcasing over 40 data points. Combining years of results unveils trends, empowering you to make informed decisions. Our visualization tools make it a breeze to compare and understand changes over time, even if your results are from different labs. A search function and filters simplify the exploration of extensive data, allowing you to focus on what needs attention.

2. All Tests View

Explore neatly organized reports on a timeline, highlighting crucial details like dates, critical results, and lab/panel names. Each report opens up to reveal in-depth descriptions and additional recommendations for each biomarker. The history of previous results is just a click away, and you can download a comprehensive report for deeper insights. Color-coded and user-friendly, it's designed for easy reading, understanding, and navigation.

3. Table View:

For a holistic view of all biomarkers side by side, our table view is your go-to. Results are neatly displayed in a categorized and dated table, ideal for those with an extensive test history. Utilize sorting, filters, and color-coding to enhance your analysis and gain extra insights.

Yes, you can download information from your account. We can compile your labs into a CSV file. To download all your labs, you can go to Account Settings, and at the bottom of the page, you will find a link to download your information.

Yes, you can print your report. To do so, navigate to "All tests" and open the report you wish to print. You'll find a print button in the right corner of the report. Click on it, and your browser's print window will open. If you prefer to print in a bigger typeface, adjust the scale using the print window settings.

Yes, you can! We highly recommend activating Two-Factor Authentication (2FA) for your account. To do so, please navigate to the "Profile and Security" section of your account, where you will find instructions for activating 2FA.

Yes, you can. When entering values for the biomarker, you will see an "Edit Range" button. Click this button, and you'll have the option to enter a custom range.

A personal account is all about keeping your own lab test results in check. It's just for you and your personal use.

The professional account is designed for health professionals who wish to track and organize their clients' laboratory results.

To learn more about Healthmatters Pro, please refer to the professional page.

Yes, you can! Simply go to the "Invite Doctor" section, enter your doctor’s email address, and send the invitation. Your doctor will receive an email with secure access to view your results. You can revoke this access at any time. All shared information is securely encrypted and protected for your privacy.
Yes, you can! Go to the Graph view or Spreadsheet view. In the top-right corner, click "Export to Excel," and the file will be downloaded to your device.

Use promo code to save 10% off any plan.


We implement proven measures to keep your data safe.

At HealthMatters, we're committed to maintaining the security and confidentiality of your personal information. We've put industry-leading security standards in place to help protect against the loss, misuse, or alteration of the information under our control. We use procedural, physical, and electronic security methods designed to prevent unauthorized people from getting access to this information. Our internal code of conduct adds additional privacy protection. All data is backed up multiple times a day and encrypted using SSL certificates. See our Privacy Policy for more details.

Navigate to Amino Acid Analysis

Popular search

1-Methylhistidine, 3-Methylhistidine, Alanine, Alpha Aminoadipic Acid, Alpha Aminobutyric Acid, Arginine, Asparagine, Aspartic Acid, Beta Aminoisobutyric Acid, Beta-Alanine, Citrulline, Cystathionine, Ethanolamine, Gamma Aminobutyric Acid, Glutamic Acid, Glutamine, Glycine, Gycine, Histidine, Homocystine, Hydroxyproline, Plasma, Isoleucine, Leucine, Lysine, Methionine, Ornithine, Phenylalanine, Proline, Sarcosine, Serine, Taurine, Threonine, Tryptophan, Tyrosine, Valine