Metabolic Bone Diseases Unit, Service of Rheumatology, Hospital Clínic, University of Barcelona, Villarroel 170, 08036, Barcelona, Spain, lgifre at clinic.ub.es.
Clin Rheumatol. 2010 Oct 15.
Osteomalacia revisited : A report on 28 cases.
Gifre L, Peris P, Monegal A, Martinez de Osaba MJ, Alvarez L, Guañabens N.
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. PMID: 20949298