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Parkinson's DiseasePhase 1/2NCT01676103

The Effects of Supplementing Tyrosine on Blood Pressure in Parkinson's Disease

A Phase 1/2 study testing Tyrosine in people with Parkinson's Disease, run by New York Institute of Technology at 1 site in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

The objective of this experiment is: Primary: To determine the effects of tyrosine supplementation on orthostatic hypotension in people with PD. Secondary: To determine the effects of tyrosine supplementation in people with PD with autonomic insufficiency on HR, BP, and norepinephrine responses during acute exercise… Read more about this study

Who is it for?
Ages 50 to 80 years
Conditions the study is for
Parkinson's Disease
What is being tested?
Tyrosine
Type of treatment
Pill or oral medicine
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
40 participants
Where
1 siteUnited States
Study dates
Sep 2012to Nov 2013
Phase
Phase 1/2
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 50 to 80 years
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Diagnosis of PD according to the UK Brain Bank Diagnostic criteria
  • Diagnosis of orthostatic hypotension according to EFNS guidelines
  • Able to walk on a treadmill comfortably for 6-10 minutes
  • Currently taking levodopa
  • Subjects between the age of 50-80 years old

Who cannot join

  • Currently taking an amino acid supplement
  • Currently taking medication that affects BP
  • Normal BP response to testing

Trial locations and contacts

1 site in 1 country.

United States1 site

  • New York Institue of Technology

    Old Westbury, New York, 11568-8000

Other trials in United States

About this study

The objective of this experiment is:

  • Primary: To determine the effects of tyrosine supplementation on orthostatic hypotension in people with PD.
  • Secondary: To determine the effects of tyrosine supplementation in people with PD with autonomic insufficiency on HR, BP, and norepinephrine responses during acute exercise stress.
Read more

Orthostatic hypotension and autonomic abnormalities are a common problem for individuals who suffer from PD, especially as it leads to lightheadedness and falling. For those affected, it can drastically reduce quality of life. It has been hypothesized that tyrosine may impact upon individuals suffering from PD. There is ample evidence in animal models that supports our theory; however there is no clinical evidence of the impact tyrosine supplementation may have in PD patients who suffer from orthostatic hypotension and blunted BP and HR responses. Positive findings that supplemental tyrosine increases BP and HR in people with PD during daily activities such as standing up from a chair and walking can lead to new therapies to improve Parkinsonian orthostatic hypotension.

Hypothesis We will test the hypothesis that symptomatic individuals with PD on dopamine therapy who suffer from orthostatic hypotension and blunted HR and BP responses will improve after tyrosine supplementation.

Being tested
Tyrosine, Placebo Comparator:Sugar Pill
Keywords
Parkinson's Disease (PD), Orthostatic hypotension (OH)
Medical subject headings
Parkinson Disease, Hypotension, Orthostatic

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • TyrosineDietary supplement

    Tyrosine supplementation (500 mg 2 x daily) for 7 days

  • Placebo Comparator:Sugar PillOther

    Placebo sugar pills (2x daily

Study groups in NCT01676103
Study groupRoleWhat they receive
TyrosineExperimentalTyrosine supplementation (500 mg 2x daily) for 7 days
Receives: Dietary Supplement: Tyrosine
Sugar pillPlacebo comparatorPlacebo sugar pills (2x daily) for 7 days
Receives: Other: Placebo Comparator:Sugar Pill

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Determine the effects of tyrosine supplementation on orthostatic hypotension in people with PD

    Orthostatic Blood Pressure Testing:

    Subjects will sit and rest for 10 minutes. Blood pressure will be taken in this resting position after the 10 minutes. Subjects will then stand upright for 3 minutes. Blood pressure will be taken every minute for those 3 minutes. A drop in systolic BP of 20 mmHg and a 10 mmHg in diastolic drop within these 3 minutes indicates orthostatic hypotension according to the American Academy of Neurology.

    Blood Samples:

    Norepinephrine and tyrosine will all be examined via blood samples drawn by a medical assistant or physician from the forearm vein in vacutainer tubes. Two vacutainers of three cc's of blood will be collected and frozen until analyzed.

    Measured: 7 days

Secondary outcomes (1)

  1. To determine the effects of tyrosine supplementation in people with PD with autonomic insufficiency on heart rate, blood pressure, and norepinephrine responses during acute exercise stress.

    An exercise stress test using a Modified Bruce Protocol, which consists of five 3-minute stages on a treadmill, will be used to implement acute stress. During the test, heart rate, oxygen consumption (VO2), Respiratory Exchange Ratio (RER), and 12 lead EKG tracings will be recorded at 1-minute intervals and BP and a rate of perceived exertion (RPE) will be recorded. The treadmill test will conclude when subjects attain peak exercise. Peak exercise will be determined when a subject attains any one of the following: 1) 85% of target heart rate; 2) an RPE of 8; 3) inability to maintain the pace of the treadmill; 4) an RER of over 1.3. Additionally, the American College of Sports Medicine (ACSM) guidelines for terminating exercise testing will be followed.

    Subjects will be tested on the first visit and then receive supplementation or placebo for 2x daily for 7 days. Subjects will then repeat all the tests they performed on the first visit.

    Measured: 7 days

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted30 Aug 2012 (estimated)
  2. Study startSep 2012
  3. Primary completionNov 2013
  4. Study completionNov 2013

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 1/2
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Masking
Double blind
Who is masked
Participant, Investigator
Enrolment
40 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT01676103
Sponsor's protocol ID
BHS-797
Status last verified
Apr 2014
First submitted
28 Aug 2012
Last updated
16 Apr 2014
Results posted
No
Data monitoring committee
No

Publications

  • Barbic F, Perego F, Canesi M, Gianni M, Biagiotti S, Costantino G, Pezzoli G, Porta A, Malliani A, Furlan R. Early abnormalities of vascular and cardiac autonomic control in Parkinson's disease without orthostatic hypotension. Hypertension. 2007 Jan;49(1):120-6. doi: 10.1161/01.HYP.0000250939.71343.7c. Epub 2006 Nov 13.

    PubMed 17101845

  • Kujawa K, Leurgans S, Raman R, Blasucci L, Goetz CG. Acute orthostatic hypotension when starting dopamine agonists in Parkinson's disease. Arch Neurol. 2000 Oct;57(10):1461-3. doi: 10.1001/archneur.57.10.1461.

    PubMed 11030798

  • Goldstein DS, Holmes CS, Dendi R, Bruce SR, Li ST. Orthostatic hypotension from sympathetic denervation in Parkinson's disease. Neurology. 2002 Apr 23;58(8):1247-55. doi: 10.1212/wnl.58.8.1247.

    PubMed 11971094

  • Sharabi Y, Goldstein DS. Mechanisms of orthostatic hypotension and supine hypertension in Parkinson disease. J Neurol Sci. 2011 Nov 15;310(1-2):123-8. doi: 10.1016/j.jns.2011.06.047. Epub 2011 Jul 16.

    PubMed 21762927

  • Karobath M, Diaz JL, Huttunen MO. The effect of L-dopa on the concentrations of tryptophan, tyrosine and serotonin in rat brain. Eur J Pharmacol. 1971 May;14(4):393-6. doi: 10.1016/0014-2999(71)90195-6. No abstract available.

    PubMed 5157767

  • Growdon JH, Melamed E, Logue M, Hefti F, Wurtman RJ. Effects of oral L-tyrosine administration on CSF tyrosine and homovanillic acid levels in patients with Parkinson's disease. Life Sci. 1982 Mar 8;30(10):827-32. doi: 10.1016/0024-3205(82)90596-3.

    PubMed 6175872

  • Glaeser BS, Melamed E, Growdon JH, Wurtman RJ. Elevation of plasma tyrosine after a single oral dose of L-tyrosine. Life Sci. 1979 Jul 16;25(3):265-71. doi: 10.1016/0024-3205(79)90294-7. No abstract available.

    PubMed 481129

  • Stryjer R, Klein C, Treves TA, Rabey JM. The effects of acute loading with levodopa and levodopa with selegiline on blood pressure and plasma norepinephrine levels in chronic Parkinson's disease patients. Acta Neurol Scand. 2005 Feb;111(2):89-94. doi: 10.1111/j.1600-0404.2005.00294.x.

    PubMed 15644067

  • Tipre DN, Goldstein DS. Cardiac and extracardiac sympathetic denervation in Parkinson's disease with orthostatic hypotension and in pure autonomic failure. J Nucl Med. 2005 Nov;46(11):1775-81.

    PubMed 16269589

  • Riederer P. L-dopa competes with tyrosine and tryptophan for human brain uptake. Nutr Metab. 1980;24(6):417-23. doi: 10.1159/000176359.

    PubMed 7219901

  • Deijen JB, Orlebeke JF. Effect of tyrosine on cognitive function and blood pressure under stress. Brain Res Bull. 1994;33(3):319-23. doi: 10.1016/0361-9230(94)90200-3.

    PubMed 8293316

  • Conlay LA, Maher TJ, Wurtman RJ. Tyrosine increases blood pressure in hypotensive rats. Science. 1981 May 1;212(4494):559-60. doi: 10.1126/science.7209553.

    PubMed 7209553

  • Conlay LA, Maher TJ, Wurtman RJ. Tyrosine accelerates catecholamine synthesis in hemorrhaged hypotensive rats. Brain Res. 1985 Apr 29;333(1):81-4. doi: 10.1016/0006-8993(85)90126-x.

    PubMed 3995291

  • Lahrmann H, Cortelli P, Hilz M, Mathias CJ, Struhal W, Tassinari M. EFNS guidelines on the diagnosis and management of orthostatic hypotension. Eur J Neurol. 2006 Sep;13(9):930-6. doi: 10.1111/j.1468-1331.2006.01512.x.

    PubMed 16930356

  • DiFrancisco-Donoghue J, Elokda A, Lamberg EM, Bono N, Werner WG. Norepinephrine and cardiovascular responses to maximal exercise in Parkinson's disease on and off medication. Mov Disord. 2009 Sep 15;24(12):1773-8. doi: 10.1002/mds.22612.

    PubMed 19562762

Questions about this trial

What is this clinical trial studying?

A Phase 1/2 study testing Tyrosine in people with Parkinson's Disease, run by New York Institute of Technology at 1 site in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 5 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 16 Apr 2014. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this combined phase mean?

Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.

Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Determine the effects of tyrosine supplementation on orthostatic hypotension in people with PD (time frame: 7 days). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT01676103, which also lists 16 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 16 Apr 2014.

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