title: Prevalence of subclinical contributors to low bone mineral density and/or fragility fracture.
abstract: OBJECTIVE
  The prevalence of subclinical contributors to low bone mineral density (BMD) and/or fragility fracture is debated. We evaluated the prevalence of subclinical contributors to low BMD and/or fragility fracture in the presence of normal 25-hydroxyvitamin D (25OHVitD) levels.
  
  
  METHODS
  Prospective observational study.
  
  
  METHODS
  Among 1095 consecutive outpatients evaluated for low BMD and/or fragility fractures, 602 (563 females, age 65.4±10.0 years) with apparent primary osteoporosis were enrolled. A general chemistry profile, phosphate, 25OHVitD, cortisol after 1-mg overnight dexamethasone suppression test, antitissue transglutaminase and endomysial antibodies and testosterone (in males) were performed. Serum and urinary calcium and parathyroid hormone levels were also evaluated after 25OHVitD levels normalization. Vertebral deformities were assessed by radiograph.
  
  
  RESULTS
  In total, 70.8% of patients had low 25OHVitD levels. Additional subclinical contributors to low BMD and/or fragility fracture were diagnosed in 45% of patients, with idiopathic hypercalciuria (IH, 34.1%) and primary hyperparathyroidism (PHPT, 4.5%) being the most frequent contributors, apart from hypovitaminosis D. Furthermore, 33.2% of IH and 18.5% of PHPT patients were diagnosed only after 25OHVitD levels normalization. The subclinical contributors to low BMD and/or fragility fracture besides hypovitaminosis D were associated inversely with age (odds ratio (OR) 1.02, 95% CI 1-1.04, P=0.04) and BMI (OR 1.1, 95% CI 1.05-1.17, P=0.0001) and directly with fragility fractures (OR 1.89, 95% CI 1.31-2.73, P=0.001), regardless of BMD.
  
  
  CONCLUSIONS
  Subclinical contributors to low BMD and/or fragility fracture besides hypovitaminosis D are present in more than 40% of the subjects with apparent primary osteoporosis. Hypovitaminosis D masks a substantial proportion of IH and PHPT patients.
authors.affiliation: Endocrinology and Diabetology Unit, Department of Clinical Sciences and Community Health, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, University of Milan, Pad. Granelli, Via F Sforza 35, 20122 Milan, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Eller-Vainicher
authors.forename: Elisa
authors.initials: E
authors.lastname: Cairoli
authors.forename: Volha V
authors.initials: VV
authors.lastname: Zhukouskaya
authors.forename: Valentina
authors.initials: V
authors.lastname: Morelli
authors.forename: Serena
authors.initials: S
authors.lastname: Palmieri
authors.forename: Alfredo
authors.initials: A
authors.lastname: Scillitani
authors.forename: Paolo
authors.initials: P
authors.lastname: Beck-Peccoz
authors.forename: Iacopo
authors.initials: I
authors.lastname: Chiodini
mesh_terms: D015502:Absorptiometry, Photon; D000368:Aged; D015519:Bone Density / Q000502:physiology*; D002118:Calcium / Q000097:blood / Q000652:urine; D005260:Female; D005272:Femur Neck / Q000000981:diagnostic imaging; D050723:Fractures, Bone / Q000097:blood / Q000000981:diagnostic imaging / Q000378:metabolism*; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000097:blood / Q000000981:diagnostic imaging / Q000378:metabolism*; D010281:Parathyroid Hormone / Q000097:blood; D011446:Prospective Studies; D012372:ROC Curve; D012680:Sensitivity and Specificity; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014953:Wrist / Q000000981:diagnostic imaging
chemical_list: D010281:Parathyroid Hormone; D014807:Vitamin D; C104450:25-hydroxyvitamin D; D002118:Calcium; D006854:Hydrocortisone