Clinical characteristics and etiologic factors of premenopausal osteoporosis in a group of Spanish women.
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.
Peris
Pilar
P
Service of Rheumatology, ICAL, IDIBAPS, Hospital Clinic, University of Barcelona, Barcelona, Spain.
Guañabens
Núria
N
Martínez de Osaba
Ma Jesús
MJ
Monegal
Ana
A
Alvarez
Luisa
L
Pons
Francesca
F
Ros
Inmaculada
I
Cerdá
Dacia
D
Muñoz-Gómez
José
J
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