Hemodynamics During the 10-Minute NASA Lean Test: Evidence of Circulatory Decompensation in a Subset of ME/CFS Patients-Lee,Unutmaz,Bateman May 2020

Sly Saint

Sly Saint

Senior Member (Voting Rights)
This preprint is under consideration at Journal of Translational Medicine. Preprints are preliminary reports that have not undergone peer review. They should not be considered conclusive, used to inform clinical practice, or referenced by the media as validated information.

Abstract

Background Lightheadedness, fatigue, weakness, heart palpitations, cognitive dysfunction, muscle pain, and exercise intolerance are some of the symptoms of orthostatic intolerance (OI). There is substantial comorbidity of OI in ME/CFS (Myalgic Encephalomyelitis/Chronic Fatigue Syndrome). The 10-minute NASA Lean Test (NLT) is a simple, point-of-care method that can aid ME/CFS diagnosis and guide management and treatment of OI. The objective of this study was t o understand the hemodynamic changes that occur in ME/CFS patients during the 10-minute NLT.

Methods A total of 150 ME/CFS patients and 75 age, gender and race matched healthy controls (HCs) were enrolled. We recruited 75 ME/CFS patients who had been sick for less than 4 years (<4 ME/CFS) and 75 ME/CFS patients sick for more than 10 years (>10 ME/CFS). The 10-minute NLT involves measurement of blood pressure and heart rate while resting supine and every minute for 10 minutes while standing with shoulder-blades on the wall for a relaxed stance. Spontaneously reported symptoms are recorded during the test. ANOVA and regression analysis were used to test for differences and relationships in hemodynamics, symptoms and upright activity between groups.

Results At least 5 minutes of the 10-minute NLT were required to detect hemodynamic changes. The <4 ME/CFS group had significantly higher heart rate and abnormally narrowed pulse pressure compared to >10 ME/CFS and HCs. The <4 ME/CFS group experienced significantly more OI symptoms compared to >10 ME/CFS and HCs. The circulatory decompensation observed in the <4 ME/CFS group was not related to age or medication use.

Conclusions Circulatory decompensation characterized by increased heart rate and abnormally narrow pulse pressure was identified in a subgroup of ME/CFS patients who have been sick for <4 years. This suggests inadequate ventricular filling from low venous pressure. The 10-minute NLT can be used to diagnose and treat the circulatory decompensation in this newly recognized subgroup of ME/CFS patients. The >10 ME/CFS group had less pronounced hemodynamic changes during the NLT possibly from adaptation and compensation that occurs over time. The 10-minute NLT is a simple and clinically useful point-of-care method that can be used for early diagnosis of ME/CFS and help guide OI treatment.
Click to expand...
https://www.researchsquare.com/article/rs-28631/v1
 
For those wanting a quick read just look at table 2. For example the first line in table 2
POTS or OH any time sequence: HC=49%, ME=54%.

I was very surprised by the amount of response to measures Healthy Controls had. I would have liked to see a breakdown showing orthostatic hypertension as well. I'm disappointed there wasn't a bigger separation between ME patients and healthy controls.

Hopefully the Solve ME sponsored study of "Hours of Upright Activity" will have sensor data for both healthy controls and patients that can show a greater separation between groups than the Nasa Lean Test. This paper only had individual self reported estimates for HUA in ME patients.

EDIT : Here is table 2
upload_2020-5-18_10-36-2.png
 
Last edited:
Thank you for this important work. It would be interesting to see the standing vital signs in order to calculate shock index while standing. I note that even while supine the overall ME/CFS group has a shock index of .6 which is considered "mild shock", according to Wikipedia (ahem, sorry). I have found the shock index to be useful in deciding whether to engage in upright activity. Pretty much anytime I am upright I am "in shock". When the index is near 1.0 ("moderate shock"), it's time to lay down.
Click to expand...

There is an interesting reader comment.
 
So this is a large study with 150 ME/CFS patients that found no statistically significant difference in the rate of POTS between ME/CFS patients and controls. This was mostly due to the high rate of POTS in the control group (33%).

Another large study with more than 400 patients, also found no statistically significant difference in the rate of POTS between ME/CFS patients and controls. However, in contrast to this study by the Bateman Horne Centre, they reported very low rates in the ME/CFS population (5.7%).

Perhaps researchers need to start thinking about other ways to explain OI in ME//CFS than in terms of hemodynamics?
 
I have a sensation in my head that is the very similar as the one that can be felt by someone that suddenly stands up after lying down and then feels faint and dizzy. This feeling is always there and not as intense as the one that occurs when suddenly standing up.

I'm not sure if I still meet the POTS diagnostic criteria (30 bpm increase when standing). I think I clearly had POTS (with emphasis on the tachycardia). This abnormal reactivity of the heart rate has improved over the past 5 years while other aspects of orthostatic intolerance have changed little.

I think it's an issue of insufficient blood getting into the head or something similar. I would have said it's low blood pressure if I didn't know my blood pressure was mostly in the norm (low-normal but nothing bad).
 
Last edited:
Grigor said:
maybe many false negatives?
Click to expand...
If I understand correctly, that study criticizes protocols that put persons only 2 or 5 minutes in an upright position while testing for POTS. The studies I quoted both used the 10-minute protocol.

Grigor said:
I'm always weary when Knoop en van der Meer are involved
Click to expand...
The biomedical studies done by Megan Roerink look alright.

EDIT: there is also an evident reason to be skeptical of positive findings of POTS namely, selection bias. The clinic by Van Campen/Visser, for example, is known to test for POTS and to prescribe medication for it, so ME/CFS patients with heart or other hemodynamic issues might be overrepresented there.
 
Michiel Tack said:
If I understand correctly, that study criticizes protocols that put persons only 2 or 5 minutes in an upright position while testing for POTS. The studies I quoted both used the 10-minute protocol.


The biomedical studies done by Megan Roerink look alright.
Click to expand...
Also the Roerink did 10 minutes? Sorry didn't read. Head not working!
 
You must log in or register to reply here.
Back
Top Bottom