CDC's Two-Day Exercise Test: Not Negotiable

Center for Disease Control's head of CFS research Dr. Beth Unger is slated to do a problematic one-day ME exercise study called the Cardiopulmonary-Exercise Testing, instead of the two-day test favored by most patients and ME-educated researchers. What’s wrong with Unger's study? 

The problem is that studies show that defects in ME patients' exercise capacity aren't evident until the second day of testing. With one-day testing, ME patients resemble deconditioned controls, a fancy phrase for couch potatoes. 

In a letter discussing her reasons for favoring the one-day study, Unger says two days would be an “unnecessary burden” for patients. Would most patients prefer a difficult one-day study that makes ME sufferers out to be indolent grumblers or a grueling two-day study that shows just how sick ME patients are? Do I really have to answer that question? Besides, the very sick patients who can't handle the second-day exercise test provide helpful data for researchers. The fact that they can't do a second day would become part of the study's findings.

Could Unger just not know about second-day crashing in ME patients?  Dr. Chris Snell, an expert in the field of exercise testing for ME patients and a proponent of two-day testing, served as president of the Chronic Fatigue Syndrome Advisory Committee (CFSAC). Unger attends its meetings, so she's aware of his work.

In citing other reasons for her decision to go ahead with one-day testing, Unger said more patients could be tested in a one-day study. To which I say: Quality, Dr. Unger. Not quantity. 

Exercise Not Negotiable 

When the one-day study shows most ME patient to be just deconditioned—not sick—the phony prescription will be, of course, exercise. Patient advocate Mary Schweitzer, in a terrific post on Unger's proposed study, calls it a set-up; I call it rigged.  

Unger believes in graded exercise for ME patients the way Republicans believe in the late Ronald Reagan. In fact, Mary Schweitzer makes this trenchant point about Unger:  

"The only time I ever saw Dr. Unger get angry in a CFSAC meeting was when we were all calling for a change in the CDC's recommendation of graded exercise. We asked not only that they quit recommending it, but also that they openly WARN physicians about the dangers. She was furious. She said that the emphasis on graded exercise was supported by scientists and was 'not negotiable.' Those very words. 'Not negotiable.' "

Patients need a CDC researcher who understands how dangerous exercise can be. How does Beth Unger get off telling patients that she knows best, that graded exercise is good for them, when it's the patients—not she—who understand this disease, who've been suffering for years if not decades? 

Patient advocate Cort Johnson has also written an in-depth piece arguing for a two-day exercise study. He points out that instead of enlisting the experts in the field to conduct the study—Snell and Stevens—CDC is calling upon Connie Sol, who, he writes, has done only one study.

Chris Snell's Studies

The way I see it, it's clear to most patients, advocates and ME-educated researchers that a two-day exercise test is necessary. In a letter, Unger explained that she had consulted Snell on which he thought was the better approach—one-day or two-day exercise testing. Snell said two-day testing. 

When asked to comment on Unger's proposed study, Snell wrote in an email to CFS Central: "Unfortunately I do not feel able to comment on the proposed CDC study at this point. I am not involved in the study and do not know much about the design, measures, or any hypotheses they intend to test. My views on exercise testing for ME/CFS are well-documented, including a number of presentations available on the WWW. The most recent is the FDA ME/CFS drug development workshop earlier this year. Please feel free to cite any of our work or public comments."

Snell and Steven's most recent study, published in June, found that two-day testing is vital in ME patients, with emphasis added:

"The objectives for this study was to determine the discriminative validity of objective measurements obtained during CPET to distinguish individuals with CFS from non-disabled sedentary individuals. Methods Gas exchange data, workloads and related physiological parameters were compared between 51 individuals with CFS and 10 control subjects, all females, for two maximal exercise tests separated by 24 hours.  Results  Multivariate analysis showed no significant differences between controls and CFS for Test 1.  However, for Test 2 the individuals with CFS achieved significantly lower values for oxygen consumption and workload at peak exercise and at the ventilatory/anaerobic threshold. Follow-up classification analysis differentiated between groups with an overall accuracy of 95.1%. Conclusions The lack of any significant differences between groups for the first exercise test would appear to support a deconditioning hypothesis for CFS symptoms. However, results from the second test indicate the presence of a CFS related post-exertional fatigue. It might be concluded that a single exercise test is insufficient to reliably demonstrate functional impairment in individuals with CFS. A second test may be necessary to document the atypical recovery response and protracted fatigue possibly unique to CFS, which can severely limit productivity in the home and workplace."

In other words, according to Snell's study, it takes two days of testing to see the poor recovery response—post-exertional malaise—in patients. 

Tom Hennessy

On another note, Tom Hennessy, a ME patient I’ve know for 19 years who lived with debilitating pain, committed suicide on September 9th. If Beth Unger, CDC and HHS spent more time doing legitimate research, perhaps patients like Tom wouldn’t feel the need to end their lives.  

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