Markus Herrmann1, Wolfgang Herrmann. 1. Department of Clinical Chemistry and Laboratory Medicine, University Hospital of Saarland, 66421 Hamburg/Saar, Germany.
Abstract
PURPOSE: Premature osteoporosis is a frequent problem in female athletes. Current concepts suggest that a disruption of the hypothalamic-pituitary axis leads to hypoestrogenism, which then causes amenorrhea and osteoporosis. However, the underlying mechanisms have been insufficiently investigated. Osteoprotegerin (OPG) and soluble TNF-alpha receptor antagonist ligand (sRANKL) regulate the balance of osteoblasts and osteoclasts. Their role in the pathogenesis of osteoporosis in female athletes has not been studied yet. METHODS: We measured OPG and sRANKL in relation to biochemical bone markers [osteocalcin (OC), bone alkaline phosphatase (BAP), serum beta-crosslaps (CTx)] and female sex hormones [estradiol (E2) and luteinizing hormone (LH)] in fastening blood samples from 25 female elite endurance athletes and 25 matched controls. RESULTS: Athletes exhibited significantly higher levels of the bone resorption marker CTx than controls (0.61 +/- 0.26 vs. 0.44 +/- 0.15 ng/ml). OPG and sRANKL were not changed. Subgroup analysis revealed that athletes using oral contraceptives [A-OCC(-)] had significantly higher levels of CTx (0.82 +/- 0.20 vs. 0.50 +/- 0.14 ng/ml), BAP [37.3 (23.2-54.4) U/l vs. 25.2 (20.3-35.6) U/l] and OPG (3.4+/-0.8 vs. 2.7+/-0.8 ng/ml) than controls who did not use oral contraceptives [C-OCC(-)]. While the difference for CTx exceeded the least significant change in this marker by approximately 30%, the differences for the bone formation markers OC and BAP were close to the least significant change. In athletes using oral contraceptives [A-OCC(+)] we found no differences compared to controls. CONCLUSIONS: A-OCC(-) athletes have increased bone turnover with a particular stimulation of bone resorption. The increased bone resorption is not accompanied by a shift of the OPG/sRANKL relationship towards an osteoclastogenic constellation. Since increased bone resorption was not detectable in A-OCC(+) athletes, it can be suggested that OCC use might protect bone health in female athletes.
PURPOSE:Premature osteoporosis is a frequent problem in female athletes. Current concepts suggest that a disruption of the hypothalamic-pituitary axis leads to hypoestrogenism, which then causes amenorrhea and osteoporosis. However, the underlying mechanisms have been insufficiently investigated. Osteoprotegerin (OPG) and soluble TNF-alpha receptor antagonist ligand (sRANKL) regulate the balance of osteoblasts and osteoclasts. Their role in the pathogenesis of osteoporosis in female athletes has not been studied yet. METHODS: We measured OPG and sRANKL in relation to biochemical bone markers [osteocalcin (OC), bone alkaline phosphatase (BAP), serum beta-crosslaps (CTx)] and female sex hormones [estradiol (E2) and luteinizing hormone (LH)] in fastening blood samples from 25 female elite endurance athletes and 25 matched controls. RESULTS: Athletes exhibited significantly higher levels of the bone resorption marker CTx than controls (0.61 +/- 0.26 vs. 0.44 +/- 0.15 ng/ml). OPG and sRANKL were not changed. Subgroup analysis revealed that athletes using oral contraceptives [A-OCC(-)] had significantly higher levels of CTx (0.82 +/- 0.20 vs. 0.50 +/- 0.14 ng/ml), BAP [37.3 (23.2-54.4) U/l vs. 25.2 (20.3-35.6) U/l] and OPG (3.4+/-0.8 vs. 2.7+/-0.8 ng/ml) than controls who did not use oral contraceptives [C-OCC(-)]. While the difference for CTx exceeded the least significant change in this marker by approximately 30%, the differences for the bone formation markers OC and BAP were close to the least significant change. In athletes using oral contraceptives [A-OCC(+)] we found no differences compared to controls. CONCLUSIONS: A-OCC(-) athletes have increased bone turnover with a particular stimulation of bone resorption. The increased bone resorption is not accompanied by a shift of the OPG/sRANKL relationship towards an osteoclastogenic constellation. Since increased bone resorption was not detectable in A-OCC(+) athletes, it can be suggested that OCC use might protect bone health in female athletes.
Authors: L Maïmoun; O Coste; D Mariano-Goulart; F Galtier; T Mura; P Philibert; K Briot; F Paris; C Sultan Journal: Osteoporos Int Date: 2011-02-26 Impact factor: 4.507