Een cohort-studie van Katz en kollega's onder adolescenten bevestigt dat
- ca. 1 op de 8 mensen een half jaar na een "onschuldige" EBV-infektie aan de
diagnose "CVS" voldoet (klik hier voor een studie die tot eenzelfde konklusie kwam),
- de zuurstofopname bij CVS-patiënten beduidend lager ligt (ca. 11%) én
- die lage inspanningskapaciteit hoogstwaarschijnlijk niet het gevolg is van deconditionering.
Citaten uit het studierapport:
There have been 11 previous reports of exercise testing in adults with CFS that included comparison (control) groups.
These studies differed in terms of the control groups examined (eg, normal vs sedentary),
whether the sickest patients with CFS were excluded,
whether the patients were encouraged to exercise to maximum capacity, and
whether only females or both sexes were studied.
Predictably, results varied as well,
but most showed decreased exercise capacity and fitness levels in subjects with CFS,
and inconsistent data regarding heart rate responses to exercise. 13-23
A single, uncontrolled pediatric study demonstrated that
maximal exercise capacity was reduced in 5% to 30% of subjects with CFS. 24
Because there were no previous controlled pediatric trials,
we undertook to prospectively examine exercise testing in our cohort of adolescents with CFS and recovered control subjects.
Neither absolute nor percent predicted work capacity was statistically significantly different between recovered control subjects and patients with CFS.
However, oxygen consumption, work slope, and peak oxygen pulse were significantly higher in recovered control
subjects than in patients who met the criteria for CFS 6 months after IM,
indicating a lower degree of fitness in CFS cases 6 months after IM versus recovered control subjects.
The 11% difference in peak oxygen consumption between adolescents with CFS and recovered control subjects is likely clinically meaningful,
because 10% to 25% increases in VO2 max are seen after aerobic training in normal individuals. 25
Because there were no abnormalities related to the efficiency of breathing,
baseline lung function, or peak work capacity,
we did see a greater rise in salivary cortisol in response to exercise in subjects with CFS,
the lower degree of fitness we saw in our CFS cohort may be related to subtle regulatory abnormalities of cardiac function.
We do not believe that there was a difference in conditioning between the 2 groups
because both baseline resting heart rate and peak hear rate were similar between the 2 groups.
Exercise tolerance testing in a prospective cohort of adolescents with chronic fatigue syndrome and recovered controls following infectious mononucleosis
J Pediatr 2010; 10.1016/j.jpeds.2010.03.025.
Ben Z. Katz, MD, Steven Boas, MD, Yukiko Shiraishi, PhD, Cynthia J. Mears, DO, and Renee Taylor, PhD
Six months after acute infectious mononucleosis (IM),
13% of adolescents meet criteria for chronic fatigue syndrome (CFS).
exercise tolerance in adolescents with CFS and control subjects 6 months after IM.
Twenty-one adolescents with CFS 6 months after IM and
21 recovered control subjects
performed a maximal incremental exercise tolerance test
with breath-by-breath gas analysis.
Values expressed are mean ± standard deviation.
The adolescents diagnosed with CFS and control subjects
did not differ in age, weight, body mass index, or peak work capacity.
Lower oxygen consumption peak percent of predicted was seen
in adolescents with CFS compared with control subjects
(CFS 99.3 ± 16.6 vs control subject 110.7 ± 19.9, P = .05).
Peak oxygen pulse also was lower in adolescents with CFS
compared with recovered control subjects
(CFS 12.4 ± 2.9 vs control subjects 14.9 ± 4.3, P = .03).
Adolescents with CFS 6 months after IM
have a lower degree of fitness and efficiency of exercise than recovered adolescents.
Whether these abnormal exercise findings are a cause or effect of CFS is unknown.
IM can lead to both fatigue and measurable changes in exercise testing
in a subset of adolescents.