补充左旋酪氨酸与纠正体位性低血压
帕金森症治疗上有一个比较难解决的问题，体位性低血压（直立性低血压），特别是用美多巴和息宁的患者，包括用一些有副作用的药物也很难处理。在我的立场，而且已经用了很长一段时间了，原来的用意是因为有研究在帕症患者的血液中发现有极低水平的酪胺酸水平，所以用来补充，后来发现对部分震颤的别人有效，而且对直立性低血压也有帮助。但酪氨酸不会令血压剧升，只是非常和缓地起作用，而且似乎在低血压改善以后就没有了升血压的作用，是否与人体自我调节有关还不能确定。
在一周前，纽约理工学院和Michael J.Fox帕金森基金会也向美国国立卫生研究院申请了一个名称是《补充酪氨酸对帕金森病患者血压的影响》（还没有正式开始），我也想看看他们的最终研究报告是否和我的观察一样，如果是，就会肯定这项研究，为帕症治疗中的低血压问题带来一个非常安全的疗法。
这项研究中用的左旋酪氨酸剂量就是我目前在用的每次500mg,每天二次。
有受直立性低血压困扰的帕症病友可以留意一下。
The Effects of Supplementing Tyrosine on Blood Pressure in Parkinson’s Disease
This study is not yet open for participant recruitment.
Verified August 2012 by New York Institute of Technology
First Received on August 28, 2012. No Changes Posted
Sponsor: New York Institute of Technology
Collaborator: Michael J. Fox Foundation for Parkinson’s Research
Information provided by (Responsible Party): New York Institute of Technology
ClinicalTrials.gov Identifier: NCT01676103
Purpose
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.
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.
Condition Intervention Phase
Parkinson’s Disease
Dietary Supplement: Tyrosine
Other: Placebo Comparator:Sugar Pill
Phase 1
Phase 2
Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Investigator)
Primary Purpose: Treatment
Official Title: The Effects of Supplementing Tyrosine on Blood Pressure in Parkinson’s Disease
Resource links provided by NLM:
Genetics Home Reference related topics: familial paroxysmal nonkinesigenic dyskinesia Perry syndrome
MedlinePlus related topics: Low Blood Pressure Parkinson’s Disease
Drug Information available for: Tyrosine
U.S. FDA Resources
Further study details as provided by New York Institute of Technology:
Primary Outcome Measures:
•Determine the effects of tyrosine supplementation on orthostatic hypotension in people with PD [ Time Frame: 7 days ] [ Designated as safety issue: No ]
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.
Secondary Outcome Measures:
•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. [ Time Frame: 7 days ] [ Designated as safety issue: No ]
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.
Estimated Enrollment: 40
Study Start Date: September 2012
Estimated Study Completion Date: September 2013
Estimated Primary Completion Date: June 2013 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Tyrosine
Tyrosine supplementation (500 mg 2x daily) for 7 days Dietary Supplement: Tyrosine
Tyrosine supplementation (500 mg 2 x daily) for 7 days
Placebo Comparator: Sugar pill
Placebo sugar pills (2x daily) for 7 days Other: Placebo Comparator:Sugar Pill
Placebo sugar pills (2x daily
