Exercise Study Links Reduced Energy Production to Fatigue in CFS, RA and Polymyositis

[Cort]

Really an interesting study. A couple of things stand out.

: PM R. 2009 Jul;1(7):620-8.
Exploratory Analysis of the Relationships between Aerobic Capacity and Self-Reported Fatigue in Patients with Rheumatoid Arthritis, Polymyositis, and Chronic Fatigue Syndrome.

Weinstein AA, Drinkard BM, Diao G, Furst G, Dale JK, Straus SE, Gerber LH.
Center for the Study of Chronic Illness and Disability, 4400 University Drive, MSN 5B7, George Mason University, Fairfax, VA 22030(dagger).

OBJECTIVE: To determine if self-reported levels of physical activity and fatigue are related to peak oxygen uptake (VO(2peak)) and whether these relationships differ among the patient groups (rheumatoid arthritis [RA], polymyositis [PM], and chronic fatigue syndrome [CFS]).

RESULTS: The Pearson r revealed that self-reported physical activity correlated with VO(2peak) (r = 61, P = .01). However, fatigability and fatigue did not correlate with VO(2peak). A trend in the data showed a distinctive relationship between fatigue/fatigability within the 3 groups. In addition, when controlling for group status, self-reported activity predicted aerobic capacity as measured by VO(2peak).

CONCLUSIONS: This study confirms that patients with chronic, but stable RA, PM, or CFS are fatigued and have significantly decreased aerobic capacity. Self-reports of physical activity predicted VO(2peak), and may be used as an indicator of activity-based aerobic capacity. Self-reports of fatigue, however, did not correlate with VO(2peak) and hence are assessing something other than an index of aerobic capacity, and provide additional information about patients' perceptions, which will require further investigation.

1. Researchers are finally examining the mechanisms of fatigue - a subject which used to garner almost no interest - but which has obvious importance to ME/CFS.
   
2. The aerobic capacity in all three diseases was reduced in fatigued patients. That the same pattern shows up in ME/CFS as other legitimized, non-controversial diseases such as rheumatoid arthritis can only help our battle for legitimacy.
   
3. That CFS even made it into a study with RA and polymyositis patients is something of a breakthrough. We've basically been known as the disease that researchers shy away from. Breast cancer researchers studying fatigue reportedly do not want ME/CFS patients in their study because of the taint CFS would bring but that did not deter these physicians. If we keep getting included in fatigue studies of other diseases that will mushroom the amount of research being done on this disease - something we sorely need. Getting in this study was a very good sign indeed.
   
4. Fatigue is an important aspect of many diseases and several diseases have a subset of inordinately fatigued patients. Do the same processes occur in those patients and ME/CFS patients? Studies like this are a start in solving that important question.
   
5. VO2 max predicted activity levels - an important finding that suggests the inability to engage in much activity has its roots in the inability of the bodies 'aerobic capacity' or it's ability to produce energy. It did not correlate with fatigue, however - other factors appear to be causing the sensation of fatigue that patients experience. (If they had done a repeat exercise test one wonders what would have shown up.)