title: Physical training increases osteoprotegerin in postmenopausal women.
abstract: The purpose of this study was to explore whether mechanical loading by exercise over a 1-year period in postmenopausal women had an effect on the receptor activator for nuclear factor kappa B ligand/osteoprotegerin (RANKL/OPG) system or the levels of the Wnt-signaling antagonist sclerostin. A total of 112 postmenopausal were randomized to either sedentary life (controls) or physical activity (training group). Ninety-two women fulfilled the study protocol. The training program consisted of three fast 30-min walks and one or two 1-h aerobic training sessions per week. The effect on the bone mineral density of the hip assessed with dual X-ray absorptiometry was positive as reported earlier. Blood samples were taken from participants at baseline and after 1 year and serum levels of OPG, RANKL and sclerostin were quantified together with the bone metabolism markers C-terminal telopeptide of collagen type I (CTX) and bone-specific alkaline phosphatase (BALP). The results were analyzed using an analysis of covariance model using baseline values as the covariate. The training group displayed a clear mean increase of OPG +7.55 pg/ml compared to controls (p = 0.007). The mean changes for RANKL +0.19 pg/ml (square-root transformed data) and sclerostin +0.62 pmol/l were non-significant (p = 0.13 and p = 0.34). The changes in bone turnover markers CTX and BALP showed a tendency to decrease in the training group versus controls but the changes were small and non-significant. Although our study is limited in number of participating women, we have been able to show an OPG-associated, and RANKL- and sclerostin-independent, training-induced inhibition of postmenopausal bone loss.
authors.affiliation: Division of Endocrinology, Metabolism and Diabetes, Karolinska University Hospital, Karolinska Institutet, Stockholm, Sweden. Ingrid.B.Bergstrom@karolinska.se
authors.forename: Ingrid
authors.initials: I
authors.lastname: Bergström
authors.forename: Paolo
authors.initials: P
authors.lastname: Parini
authors.forename: Sven A
authors.initials: SA
authors.lastname: Gustafsson
authors.forename: Göran
authors.initials: G
authors.lastname: Andersson
authors.forename: Jonas
authors.initials: J
authors.lastname: Brinck
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000368:Aged; D000469:Alkaline Phosphatase / Q000097:blood; D015519:Bone Density / Q000502:physiology; D019485:Bone Morphogenetic Proteins / Q000097:blood; D001842:Bone and Bones / Q000201:enzymology; D024042:Collagen Type I / Q000097:blood; D005260:Female; D005819:Genetic Markers; D006615:Hip / Q000502:physiology; D006801:Humans; D008875:Middle Aged; D009043:Motor Activity; D053244:Osteoprotegerin / Q000097:blood*; D010455:Peptides / Q000097:blood; D017698:Postmenopause / Q000097:blood*; D053245:RANK Ligand / Q000097:blood
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D019485:Bone Morphogenetic Proteins; D024042:Collagen Type I; D005819:Genetic Markers; D053244:Osteoprotegerin; D010455:Peptides; D053245:RANK Ligand; C422903:SOST protein, human; C506030:TNFRSF11B protein, human; C052929:collagen type I trimeric cross-linked peptide; D000469:Alkaline Phosphatase