April 4, 2009
“We believe that this study will help to determine the specific cause of POTS in CFS and will point towards improved medical therapy for younger CFS patients.”
This study involving two days of testing at New York Medical College in Westchester County, New York, is focused on understanding circulatory factors that may explain and lead to effective therapies for the symptoms of 'chronic fatigue syndrome' (ME/CFS) in young people ages 15 - 29.
The study, led by pediatric physiologist Dr. Julian M Stewart, MD, PhD, Director of NYMC’s Center for Hypotension, offers the testing free (including testing of potentially helpful medications in relevant subjects) plus a small stipend.
To quote the study description:
“What Comprises the Study Population? We are seeking patients aged 15-29 years old patients with chronic fatigue syndrome (CFS) with or without any overt form of cardiovascular or circulatory disease. While many young people with CFS have a form of overt chronic orthostatic intolerance (the inability to remain upright without symptoms) there are many others who do not.
“Yet the latter group may still have abnormalities of the small blood vessels, also called microvessels, that are most important in the regulation of blood volume and blood flow. Thus, some of the CFS patients have symptoms of chronic orthostatic intolerance such as dizziness, nausea, headache, pallor, and neurocognitive loss (difficulty thinking) which overlap with the case definition of CFS.
“Others may not have obvious symptoms while standing, but might still have blood vessel abnormalities (i.e., vascular dysfunction) that contribute to fatigue and might benefit from specific therapy.
"What is the hypothesis and importance? Blood flow abnormalities associated with the postural tachycardia syndrome (POTS) produce major disability in younger chronic fatigue syndrome (CFS) patients. These may be due to defects:
• In a fundamental signaling molecule called nitric oxide (NO)
• Or in its interaction with another molecule called angiotensin. In the current proposal we will determine how NO and angiotensin produce POTS in CFS patients and whether drugs that alter NO and angiotensin can improve patient health.
“We will subset CFS patients by POTS using upright tilt, and subgroup POTS based on noninvasive measurements of peripheral blood flow. Some patients who we denote low flow CFS/POTS have reduced peripheral blood flow, while others have normal flow.
“We will determine whether low flow CFS/POTS is due to decreased NO produced by nNOS and related to increased angiotensin-II (A-II) and oxidative stress. We will measure skin blood flow with lasers, and NO and angiotensin by intradermal microdialysis tiny tubes in the skin), and use local heating and chemical responses in the skin to a commonly used blocker of angiotensin called losartan. If losartan works in the skin we will try to treat low blood flow with oral losartan and measure the extent of improvement in blood flow throughout your body.
“Data suggest that NO is increased in normal flow CFS/POTS at least in the gut circulation causing pooling of blood during upright posture. We will determine whether this is true in the skin. If this is true in the skin, we will test whether a systemic medication called octreotide reduces orthostatic gut blood pooling and cutaneous microvascular NO dependent responses."
FOR MORE INFORMATION AND A SCREENING APPLICATION
To learn much more about the study and eligibility criteria, for contact information, and to access a Screening Application, go to the study listing on the NYMC site (http://www.nymc.edu/fhp/centers/syncope/Vascular%20Dysfunction%20in%20CFS.htm)
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