Chronic fatigue syndrome: a risk factor for osteopenia?
No data documenting a possible depletion of bone mineral density in patients with chronic fatigue syndrome (CFS) are currently available. However, recent pathophysiological observations in CFS patients may have deleterious consequences on bone density. Firstly, the deregulation of the 2,5A synthetase RNase L antiviral pathway and its associated channelopathy, implicates increased demands for calcium and consequent increased calcium-re-absorption from the skeletal system. Secondly, Mycoplasma fermentans which has been frequently associated with CFS, produces a lipopeptide, named 2-kDa macrophage-activating lipopeptide (MALP-2), which stimulates macrophages. MALP-2 has been shown to enhance bone resorption in a dose-dependent manner, at least in part by stimulating the formation of prostaglandins. Thirdly, decreased levels of insulin-like growth factor I (IGF-I) have been reported in CFS-patients. IGF-I is critical to the proliferation of osteoblasts. Consequently, depleted levels of IGF-I may shift the balance between osteoclastic and osteoblastic activity towards bone resorption.
Nijs
Jo
J
Department of Human Physiology, Faculty of Physical Education and Physiotherapy, Vrije Universiteit Brussel, Brussel, Belgium. Jo.Nijs@vub.ac.be
De Meirleir
Kenny
K
Englebienne
Patrick
P
McGregor
Neil
N
D015088:2',5'-Oligoadenylate Synthetase / Q000378:metabolism; D015519:Bone Density; D001851:Bone Diseases, Metabolic / Q000209:etiology* / Q000503:physiopathology; D001862:Bone Resorption; D004722:Endoribonucleases / Q000378:metabolism; D015673:Fatigue Syndrome, Chronic / Q000150:complications* / Q000503:physiopathology; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000172:deficiency; D008954:Models, Biological; D009175:Mycoplasma Infections / Q000150:complications / Q000503:physiopathology; D016858:Mycoplasma fermentans / Q000472:pathogenicity; D012307:Risk Factors
D007334:Insulin-Like Growth Factor I; D015088:2',5'-Oligoadenylate Synthetase; D004722:Endoribonucleases; C031956:2-5A-dependent ribonuclease