title: Clinical characteristics and etiologic factors of premenopausal osteoporosis in a group of Spanish women.
abstract: OBJECTIVE
  To analyze the clinical characteristics and the principal causes of osteoporosis in premenopausal women.
  
  
  METHODS
  This study included 52 osteoporotic premenopausal women ages 20-51 years (mean 36.2 +/- 7) who were referred to an outpatient rheumatology department for osteoporosis evaluation. Bone mass assessment, automated biochemical profile, urinary calcium excretion, and bone marker assays were performed on all patients. Hormonal measurements were made when a specific etiology was not readily apparent. The diagnosis of osteoporosis was defined by the presence of atraumatic vertebral fractures and/or by densitometric criteria. Previous skeletal fractures, weight, height, body mass index (BMI), age at menarche, and family history of osteoporosis also were recorded.
  
  
  RESULTS
  Twenty-nine patients (56%) had idiopathic osteoporosis and 23 (44%) had secondary osteoporosis. Fifteen patients (29%) had vertebral fractures and 12 had previous peripheral fractures. Patients with secondary osteoporosis showed higher BMI (23.2 +/- 3 v 21.2 +/- 2, P =.02) and lower femoral Z-scores of bone mineral density (BMD) (-2.1 +/- 0.6 v -1.5 +/- 0.9, P =.02) than those with idiopathic disease. The most frequent causes of secondary osteoporosis included Cushing syndrome, pregnancy osteoporosis, and osteogenesis imperfecta. Nearly half of the patients (48%) with idiopathic osteoporosis had a family history of osteoporosis. In addition, 11 patients (38%) with idiopathic osteoporosis had associated hypercalciuria. Except for an increase in urinary calcium excretion (248 +/- 53 v 143 +/- 47 mg/24 h, P <.0001), no other significant differences in the remaining variables analyzed were found between hypercalciuric and normocalciuric patients with idiopathic osteoporosis.
  
  
  CONCLUSIONS
  Idiopathic osteoporosis was the most frequent diagnosis of pre-menopausal osteoporosis in our unit. These patients showed lower BMI and higher femoral neck Z-scores than patients with secondary causes. A family history of osteoporosis and hypercalciuria were factors frequently associated with this disorder.
authors.affiliation: Service of Rheumatology, ICAL, IDIBAPS, Hospital Clinic, University of Barcelona, Barcelona, Spain.
authors.forename: Pilar
authors.initials: P
authors.lastname: Peris
authors.forename: Núria
authors.initials: N
authors.lastname: Guañabens
authors.forename: Ma Jesús
authors.initials: MJ
authors.lastname: Martínez de Osaba
authors.forename: Ana
authors.initials: A
authors.lastname: Monegal
authors.forename: Luisa
authors.initials: L
authors.lastname: Alvarez
authors.forename: Francesca
authors.initials: F
authors.lastname: Pons
authors.forename: Inmaculada
authors.initials: I
authors.lastname: Ros
authors.forename: Dacia
authors.initials: D
authors.lastname: Cerdá
authors.forename: José
authors.initials: J
authors.lastname: Muñoz-Gómez
mesh_terms: D000328:Adult; D015519:Bone Density; D005260:Female; D005272:Femur Neck / Q000000981:diagnostic imaging / Q000378:metabolism; D015775:Fractures, Stress / Q000453:epidemiology; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000378:metabolism; D008875:Middle Aged; D010024:Osteoporosis / Q000453:epidemiology / Q000209:etiology* / Q000378:metabolism; D010045:Outpatients; D017697:Premenopause; D011859:Radiography; D013030:Spain / Q000453:epidemiology; D016103:Spinal Fractures / Q000453:epidemiology