Idiopathic osteoporosis in premenopausal women. Clinical characteristics and bone remodelling abnormalities.
OBJECTIVE
Osteoporosis is infrequent in young premenopausal women and is often associated with secondary disorders. However, idiopathic osteoporosis may be found in this setting and few data are known on this condition. Therefore, the aim of this study was to analyse the clinical characteristics and bone remodelling abnormalities in premenopausal women with idiopathic osteoporosis.


METHODS
28 premenopausal women with idiopathic osteoporosis (aged 38.3+/-7.6 years) were included. The patients had one or more fragility fractures and/or decreased bone mass (z-score <-2 in the lumbar spine or femur). In all patients, secondary causes of osteoporosis were excluded and previous skeletal fractures, family history and risk factors for osteoporosis were recorded. In addition, bone mineral density at the lumbar spine and hip, spinal x-rays, and laboratory tests including PTH, 25-hydroxyvitamin D, 1,25 (OH)<inf>2</inf> vitamin D and urinary calcium excretion were measured. Bone markers such as serum bone alkaline phosphatase (bone AP) and P1NP, and urinary hydroxyproline (HYP), NTx and CTx were measured and results were compared with those observed in a control group of 28 healthy premenopausal women.


RESULTS
46% of the patients had previous fragility fractures, 53% had family history of osteoporosis, 36% had associated hypercalciuria and 30% had a BMI <20 Kg/m2. Patients with idiopathic osteoporosis had increased bone resorption markers (NTx and HYP) but normal bone formation markers when compared with healthy controls. No significant differences in the clinical and biochemical parameters were observed between patients with or without hypercalciuria.


CONCLUSIONS
Young women with idiopathic osteoporosis have an increased bone resorption without changes in bone formation when assessed by biochemical markers.
Peris
P
P
Services of 1Rheumatology, Hospital Clínic, University of Barcelona, Institut d'Investigacions Biomédiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.
Ruiz-Esquide
V
V
Monegal
A
A
Alvarez
L
L
Martínez de Osaba
M J
MJ
Martínez-Ferrer
A
A
Reyes
R
R
Guañabens
N
N
D000328:Adult; D015415:Biomarkers; D015519:Bone Density; D016723:Bone Remodeling; D005260:Female; D050723:Fractures, Bone / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology; D006801:Humans; D053565:Hypercalciuria / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology; D008875:Middle Aged; D010024:Osteoporosis / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology*; D017697:Premenopause; D012307:Risk Factors
D015415:Biomarkers