TGF-β1, bone metabolism, osteoprotegerin, and soluble receptor activator of nuclear factor-kB ligand in girls with anorexia nervosa.
BACKGROUND
Numerous investigations, and especially in vitro studies, indicate that TGF-β1 may act as an important regulator of bone remodelling. Thus, it could be expected that disturbances of this cytokine production observed by several researchers might play a role in the mechanism leading to the development of osteoporosis in girls with anorexia nervosa (AN). The aim of the study was to determine whether 1) girls with AN exhibited a relationship between TGF-β1 and bone metabolism (as assessed based on serum OC and CTx concentrations) and 2) whether OPG and sRANKL might modify the possible relationship between TGF-β1 and bone metabolism.


METHODS
Serum concentrations of TGF-β, OC, CTx, OPG, and its soluble ligand sRANKL were determined by ELISA in 60 girls with AN and in 20 healthy controls (C). All study participants were aged 13 to 17 years.


RESULTS
Body weight, BMI, BMI-SDS and the Cole index, serum TGF-β1, OC, CTx, and the OPG/sRANKL ratio were significantly reduced, while OPG and sRANKL levels were significantly increased, in girls with AN compared to healthy participants. BMI and the Cole index correlated negatively and significantly with serum CTx and OPG (AN group) or CTx only (groups C and C + AN). Girls with AN showed a positive and significant correlation between the Cole index and serum TGF-β1. The combination group (C + AN) showed a positive and significant correlation between BMI, the Cole index, and the OPG/sRANKL ratio and TGF-β1 concentration, while TGF-β1 correlated positively and significantly with OC concentrations and the OPG/sRANKL ratio. The Cole index and BMI were identified to be significant and independent predictors of CTx (C, AN, and C+AN groups) and OPG (AN group); the Cole index, BMI, and TGF-β1 independently predicted the OPG/sRANKL ratio (C, AN, and C + AN groups); TGF-β1 was found to be an independent predictor of OC (C + AN group).


CONCLUSIONS
Changes in bone markers, OPG, and/or OPG/sRANKL ratio observed in girls with AN are associated with changes in serum TGF-β1 concentrations. TGF-β1 suppression in girls with AN might lead to disturbances in the relationship between bone metabolism and the OPG/sRANKL system, which, in turn, might compromise the mechanism compensating for bone remodelling disturbances. (Endokrynol Pol 2016; 67 (5): 493-500).
Department of Medical and Molecular Biology, School of Medicine with the Division of Dentistry in Zabrze, Medical University of Silesia, Katowice. ozdrasiek@wp.pl.
Zofia
Z
Ostrowska
Katarzyna
K
Ziora
Joanna
J
Oświęcimska
Elżbieta
E
Świętochowska
Bogdan
B
Marek
Dariusz
D
Kajdaniuk
Joanna
J
Strzelczyk
Karolina
K
Gołąbek
Kinga
K
Wołkowska-Pokrywa
Beata
B
Kos-Kudła
D000293:Adolescent; D000856:Anorexia Nervosa / Q000150:complications / Q000378:metabolism* / Q000503:physiopathology; D016723:Bone Remodeling; D001842:Bone and Bones / Q000378:metabolism* / Q000503:physiopathology; D005260:Female; D006801:Humans; D010024:Osteoporosis / Q000209:etiology; D053244:Osteoprotegerin; D053246:Receptor Activator of Nuclear Factor-kappa B; D053773:Transforming Growth Factor beta1
D053244:Osteoprotegerin; D053246:Receptor Activator of Nuclear Factor-kappa B; C508960:TGFB1 protein, human; C506030:TNFRSF11B protein, human; D053773:Transforming Growth Factor beta1
OPG; TGF-β1; anorexia nervosa; bone metabolism; girls; sRANKL