Comment on: Strength and physiological response to exercise in patients with chronic fatigue syndrome. [J Neurol Neurosurg Psychiatry. 2000]
It is increasingly recognised that chronic fatigue syndrome (CFS) is heterogeneous. A significant proportion of patients fulfilling operative criteria for a diagnosis of CFS will also fulfill criteria for a psychiatric disorder, such as depression or somatisation. Failure to recognise this heterogeneity prejudices attempts to understand CFS in cross sectional studies. In this issue (pp 302–307) Fulcher et al report a study of muscle strength, aerobic exercise capacity, and functional incapacity in a group of patients with CFS without concurrent psychiatric disorder, compared with patients with major depression and a group of normal but sedentary subjects.1 In an incremental treadmill exercise test, patients with CFS and depressed patients had lower peak oxygen consumption rates, maximal heart rates, and plasma lactate concentrations than the sedentary controls; but this reflected the shorter duration of exercise tolerated by these patients. At submaximal work rates, patients with CFS and depressed patients experienced greater perception of eVort than sedentary controls at the same level of work. This is in keeping with the finding that such patients show greater sensitivity to bodily sensations than normal subjects. Overall, there was little difference between the patients with CFS and the depressed patients in exercise characteristics, yet the patients with CFS reported significantly greater degrees of physical fatigue and physical incapacity.
You can read the full comment here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1737076/pdf/v069p00289.pdf
Source: Lane R. Chronic fatigue syndrome: is it physical? J Neurol Neurosurg Psychiatry. 2000 Sep;69(3):289. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1737076/