title: Serum chitotriosidase in postmenopausal women with severe osteoporosis.
abstract: Human chitotriosidase (Chit) increases during the osteoclast differentiation and their activity. We demonstrated that serum Chit was significantly higher in osteoporotic subjects than in healthy control ones and revealed a negative correlation between Chit and bone mineral density (BMD). This is the first study showing a correlation between Chit and severe postmenopausal osteoporosis.
  
  
  BACKGROUND
  Mammalian chitinases exert important biological roles in the monocyte lineage and chronic inflammatory diseases. In particular, Chit seems to promote bone resorption in vitro. No in vivo studies have been performed to confirm this finding. We aim to evaluate Chit activity in postmenopausal women affected by severe osteoporosis.
  
  
  METHODS
  In this cross-sectional study, 91 postmenopausal women affected by osteoporosis and 61 with either osteopenia or normal BMD were screened. All subjects were assessed by dual-energy X-ray absorptiometry (DXA) and X-ray vertebral morphometry. Osteoporotic subjects were considered eligible if they were affected by at least one vertebral osteoporotic fracture (group A = 57 subjects). Osteopenic or healthy subjects were free from osteoporotic fractures (group B = 51 subjects). Enzymatic Chit and serum β-CrossLaps (CTX) were measured in the whole population.
  
  
  RESULTS
  Group A showed higher serum levels of beta-CTX compared to group B (0.40 ± 0.26 ng/mL vs 0.29 ± 0.2 ng/mL, p = 0.022). Chit was significantly higher in group A than in group B (1042 ± 613 nmol/mL/h vs 472 ± 313 nmol/mL/h, p < 0.001, respectively) even after adjustment for age (p < 0.001). Spearman correlation test revealed a negative correlation between Chit and BMD at each site (lumbar spine: r = -0.38, p = 0.001, femoral neck: r = -0.35, p = 0.001, total femur: r = -0.39, p < 0.001). Furthermore, a positive correlation between Chit and PTH was observed (r = 0.26, p = 0.013). No significant correlation was found between Chit and beta-CTX (r = 0.12, p = 0.229). After a multivariate analysis, a positive correlation between severe osteoporosis and Chit (p < 0.001), beta-CTX (p = 0.013), and age (p < 0.001) was observed.
  
  
  CONCLUSIONS
  This is the first clinical study showing a correlation between Chit and severe postmenopausal osteoporosis. Larger and prospective studies are needed to evaluate if Chit may be a promising clinical biomarker and/or therapeutic monitor in subjects with osteoporosis.
authors.affiliation: Clinical Pathology and Microbiology Laboratory, University Campus Bio-Medico, Rome, Italy.|Department of Orthopaedic surgery, University Campus Bio-Medico, Rome, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Musumeci
authors.affiliation: Department of Endocrinology and Diabetes, University Campus Bio-Medico, Via Alvaro del Portillo, 21 - 00128, Rome, Italy. a.palermo@unicampus.it.
authors.forename: A
authors.initials: A
authors.lastname: Palermo
authors.affiliation: Department of Endocrinology and Diabetes, University Campus Bio-Medico, Via Alvaro del Portillo, 21 - 00128, Rome, Italy.
authors.forename: L
authors.initials: L
authors.lastname: D'Onofrio
authors.affiliation: Department of Orthopaedic surgery, University Campus Bio-Medico, Rome, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Vadalà
authors.affiliation: Department of Endocrinology and Diabetes, University Campus Bio-Medico, Via Alvaro del Portillo, 21 - 00128, Rome, Italy.
authors.forename: V
authors.initials: V
authors.lastname: Greto
authors.affiliation: Institute of Biochemistry and clinical Biochemistry, University Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Di Stasio
authors.affiliation: Department of Endocrinology and Diabetes, University Campus Bio-Medico, Via Alvaro del Portillo, 21 - 00128, Rome, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Maddaloni
authors.affiliation: Department of Bio-medical Sciences, University of Catania, Catania, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Di Rosa
authors.affiliation: Department of Clinical and Molecular Biomedicine, University of Catania, Ospedale Ferrarotto, Catania, Italy.
authors.forename: D
authors.initials: D
authors.lastname: Tibullo
authors.forename: S
authors.initials: S
authors.lastname: Angeletti
authors.affiliation: Clinical Pathology and Microbiology Laboratory, University Campus Bio-Medico, Rome, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Silvia
authors.affiliation: Department of Endocrinology and Diabetes, University Campus Bio-Medico, Via Alvaro del Portillo, 21 - 00128, Rome, Italy.
authors.forename: N
authors.initials: N
authors.lastname: Napoli
authors.affiliation: Department of Orthopaedic surgery, University Campus Bio-Medico, Rome, Italy.
authors.forename: V
authors.initials: V
authors.lastname: Denaro
authors.affiliation: Department of Endocrinology and Diabetes, University Campus Bio-Medico, Via Alvaro del Portillo, 21 - 00128, Rome, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Manfrini
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D015519:Bone Density / Q000502:physiology; D016022:Case-Control Studies; D004796:Clinical Enzyme Tests / Q000379:methods; D003430:Cross-Sectional Studies; D005260:Female; D005269:Femur / Q000503:physiopathology; D006596:Hexosaminidases / Q000097:blood*; D006801:Humans; D008159:Lumbar Vertebrae / Q000503:physiopathology; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000175:diagnosis / Q000201:enzymology* / Q000503:physiopathology; D058866:Osteoporotic Fractures / Q000201:enzymology / Q000503:physiopathology; D016103:Spinal Fractures / Q000201:enzymology / Q000503:physiopathology
chemical_list: D015415:Biomarkers; D006596:Hexosaminidases; C086400:chitotriosidase
keywords: Chitotriosidase; Fracture; Osteoporosis; Serum CTX