Osteomalacia revisited : a report on 28 cases.
The aim of this study was to analyse the clinical manifestations and the most frequent causes of osteomalacia (OM) in a group of 28 patients diagnosed with this disorder during a 20-year period. OM was diagnosed by bone biopsy and/or by Bingham and Fitzpatrick criteria (two of the following: low calcium, low phosphate, elevated total alkaline phosphatase [total AP] or suggestive radiographs). Of these patients, 13 had vitamin D deficiency OM (VD-OM), 14 hypophosphatemic OM (HypoP-OM) and one had OM-associated hypophosphatasia. Deficient sun exposure and celiac disease were the most frequent etiologies of VD-OM, whereas most HypoP-OM were hereditary forms. The main clinical symptoms were polyarthralgias (89%), frequently associated with fractures (75%). Fifty seven percent had densitometric criteria of osteoporosis. Patients with VD-OM showed significantly higher total AP and PTH serum values, but lower vitamin D, serum calcium, calciuria and bone mass than patients with HypoP-OM. Conversely, HypoP-OM patients had significantly lower serum phosphate and higher phosphaturia than patients with VD-OM. Briefly, high total AP, low serum calcium and low serum phosphate were observed in 85%, 65% and 15%, respectively, of patients with VD-OM, being observed in 64%, 14% and 100%, respectively, of HypoP-OM patients. Nearly 50% of these latter showed increased FGF23 levels. In conclusion, in this study, the frequencies of HypoP-OM and VD-OM were similar. The most frequent laboratory abnormalities were increased total AP and decreased serum phosphate. A urinary calcium loss of less than 50 mg/dl was highly discriminatory for VD-OM and a serum phosphate less than 2.3 mg/dl was also high discriminatory for HypoP-OM. Low densitometric values and fractures were frequent among these patients.
Metabolic Bone Diseases Unit, Service of Rheumatology, Hospital Clínic, University of Barcelona, Villarroel 170, 08036, Barcelona, Spain. lgifre@clinic.ub.es
Laia
L
Gifre
Pilar
P
Peris
Ana
A
Monegal
Maria Jesús
MJ
Martinez de Osaba
Luisa
L
Alvarez
Núria
N
Guañabens
D000328:Adult; D000368:Aged; D001706:Biopsy; D015519:Bone Density; D001842:Bone and Bones / Q000473:pathology; D005260:Female; D000089703:Fibroblast Growth Factor-23; D050723:Fractures, Bone; D006801:Humans; D007014:Hypophosphatasia / Q000150:complications; D017674:Hypophosphatemia / Q000150:complications; D007015:Hypophosphatemia, Familial / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D010018:Osteomalacia / Q000150:complications / Q000175:diagnosis* / Q000628:therapy*; D010281:Parathyroid Hormone / Q000097:blood; D014808:Vitamin D Deficiency / Q000150:complications
C000717427:FGF23 protein, human; D010281:Parathyroid Hormone; D000089703:Fibroblast Growth Factor-23