Diagnosis Of Osteomalacia Research Articles

Osteopenia and osteomalacia after gastrectomy: interrelations between biochemical markers of bone remodelling, vitamin D metabolites, and bone histomorphometry.

The prevalence of metabolic disease in a population of 68 postgastrectomy patients was assessed using histomorphometric evaluation of transiliac bone biopsy specimens after tetracycline double labelling. Trabecular bone volume was significantly lower in the postgastrectomy group (p less than 0.01): 62% of the patients had increased osteoid surface, 56% increased osteoid thickness, and 24% increased mineralisation lag time. Only 18%, however, fulfilled the diagnostic criteria for osteomalacia--increased osteoid thickness and increased mineralisation lag time. Postgastrectomy patients had reduced serum concentrations of calcium (p less than 0.01), phosphate (p less than 0.01), and 25-hydroxyvitamin D, while levels of alkaline phosphatase and 1,25 dihydroxyvitamin D were high (p less than 0.01). The severity of the mineralisation defect as reflected by mineralisation lag time was positively correlated to serum 25-hydroxyvitamin D, but unrelated to serum 1,25-dihydroxyvitamin D. Multiple linear regression analysis showed that serum 25-hydroxyvitamin D, age, and the duration of postoperative follow up were significant determinants of the mineralisation defect in a given patient. The limited value of serum markers in the diagnosis of osteomalacia was emphasised by the fact that six of the eight patients with osteomalacia had normal serum levels of calcium and alkaline phosphatase, and five of the eight had values for 25-hydroxyvitamin D in the normal range for healthy control subjects. The results clearly show the need for vitamin D supplementation and regular control after gastric resection.

Low Prevalence of Osteomalacia in Elderly Patients with Hip Fracture

In order to establish the prevalence of osteomalacia in elderly patients with hip fracture, trans-iliac biopsies were obtained from 49 patients, aged 67-92 years, admitted to Cardiff Royal Infirmary with hip fracture. Undecalcified sections were quantitatively assessed and the diagnosis of osteomalacia was made when there was an increase in mean osteoid seam width (greater than 15 microns) associated with a reduction in calcification fronts (less than 60% of osteoid-covered surfaces). Osteomalacia was present in only one patient; in the remaining patients, osteoid surface extent, volume and mean seam width were within normal limits. Thus osteomalacia, when defined by rigorous histomorphometric criteria, was rare in these elderly subjects with hip fracture.

Timing of screening for osteomalacia in the acutely ill elderly.

Hypocalcaemia and hypophosphataemia either on admission or before discharge from hospital are poor discriminators for the presence of subclinical osteomalacia in the elderly. Reliance has to be placed on the measurement of alkaline phosphatase even though false positive tests are common. Use of paired admission and predischarge data reduces the false positive rate by approximately 50% thereby reducing the requirement for histological confirmation of the diagnosis of osteomalacia. Since the prevalence of osteomalacia is low in this type of hospital population, any measure which reduces the requirement for bone biopsy is of considerable practical value.

Osteomalacia associated with prostatic cancer and osteoblastic metastases

A patient with carcinoma of the prostate, extensive bony metastases, and osteomalacia is reported. The diagnosis of osteomalacia was suspected because of generalized weakness and bone pains, hypocalcemia, hypophosphatemia, and raised alkaline phosphatase. It was documented by low 1,25-hydroxyvitamin D level. Furthermore, it was confirmed by improvement in patient's symptomatology and normalization of serum calcium and phosphorus after treatment with 1,25-hydroxyvitamin D 3 (Rocaltrol).

Value of plasma calcium, phosphate, and alkaline phosphatase measurements in the diagnosis of histological osteomalacia.

Plasma calcium and phosphate concentrations and alkaline phosphatase activities were examined retrospectively in 50 patients with histologically proven osteomalacia and 50 age- and sex-matched control subjects with normal bone histology. An abnormal plasma alkaline phosphatase activity was more useful than an abnormal plasma calcium or phosphate concentration in distinguishing between normal and osteomalacic subjects, producing a false-negative rate of 14% and a false-positive rate of 8%. False-negative and false-positive rates of 10% and 8% respectively were obtained when the presence of an abnormality in any one of the three biochemical measurements was used as a predictor of histological osteomalacia. When discriminant analysis was applied to plasma calcium, phosphate and alkaline phosphatase together a false-negative rate of 12% and a false-positive rate of 0% was obtained.Sixty-two patients in whom a diagnosis of osteomalacia was suspected were investigated prospectively, using both single biochemical abnormalities and the classification functions derived from the discriminant analysis of all three biochemical measurements to predict the presence or absence of histological osteomalacia. Plasma alkaline phosphatase activity gave false-negative and false-positive rates of 10% and 32% respectively but was a more reliable predictor of abnormal bone histology than were plasma calcium or plasma phosphate concentrations or the presence of an abnormality in any one of the three measurements. Discriminant analysis using plasma calcium, phosphate and alkaline phosphatase together produced a false-negative rate of 16% and a false-positive rate of 10%. We conclude that plasma alkaline phosphatase activity is the best single routine biochemical screening test for osteomalacia, although a high false-positive rate may occur. Direct discriminant analysis of plasma calcium, phosphate and alkaline phosphatase together provides a more sensitive method of detecting histological osteomalacia which should be useful in determining the prevalence of osteomalacia within high-risk populations.

Isotopic scanning of bone in the diagnosis of osteomalacia.

Results of a study performed over 18 months in 21 elderly patients showed that isotopic bone scanning is a sensitive technique for the detection of osteomalacia. It can be used not only to indicate the presence of the disease but the response to treatment.

Concentrations of Calcium, inorganic phosphorus and alkaline phosphatase in the sera of lactating women in North India.

Serum calcium, inorganic phosphorus and alkaline phosphatase (SAP) have been determined in 75 lactating women and 25 controls. 25 lactating women were re-investigated after administration of calcium and vitamin D supplements of 1 month. Lactating women showed statistically significant hypocalcaemia and raised SAP. However, the elevation of the enzyme level was significantly lower in women with milk intakes of more than 1/2 litre per day and in those in later months of lactation. The effects of calcium and vitamin D supplementation supported a diagnosis of osteomalacia in a large percentage of lactating women.

Osteomalacia in rheumatoid arthritis.

Fifty-four patients with rheumatoid arthritis and severe osteomalacia were found to have considerable bone and general deficiency problems. In 46 of them 14 stress fractures occurred and 32 minimal trauma fractures necessitating admission to hospital. Radiological abnormalities of absorption were found in nearly 25% of the total, implying that dietary factors alone are not always responsible for osteomalacia in patients with rheumatoid arthritis. A high index of suspicion is necessary in the diagnosis of osteomalacia in patients with rheumatoid arthritis, so they may benefit from treatment.

Effect of vitamin D 3 (cholecalciferol) in anticonvulsant osteomalacia

Two patients who had been receiving anticonvulsant drugs for 12 and 18 years respectively are described. The findings of myopathy, bone pain and fractures combined with hypophosphatemia, a raised alkaline phosphatase and generalised aminoaciduria were consistent with a diagnosis of osteomalacia. Undecalcified bone sections confirmed the presence of severe osteomalacia. The finding of a low circulating level of 25-OH vitamin D combined with a dramatic clinical, biochemical and histological response to a single dose of intravenous vitamin D 3 (cholecalciferol), 1 mg, suggested a state of vitamin D deficiency. Dietary intake of vitamin D was normal and intestinal malabsorption excluded in both patients. Absorption of 25-OH vitamin D 3, studied in one patient, was normal. These observations support the view that in anticonvulsant osteomalacia, the state of vitamin D deficiency is related to deranged metabolism of the vitamin induced by anticonvulsant drugs.

Calcium balance in drug‐induced osteomalacia: Response to vitamin D

The effect of oral vitamin D3 therapy on calcium balance was compared in 18 institutionalized subjects with drug-induced osteomalacia and in 18 similar subjects without osteomalacia. The subjects with osteomalacia were receiving standard doses of phenytoin and phenobarbital. Diagnosis of osteomalacia was based on low serum calcium and phosphorus, elevated alkaline phosphatase, and appropriate roentgenographic bone changes. The study group achieved positive calcium balance at approximately 975 IU of vitamin D3 per day, while the control group achieved positive calcium balance at approximately 380 IU of vitamin D3 per day. The difference is highly significant (p less than 0.001). These data support previous observations that the osteomalacia of patients receiving anticonvulsant drugs is related to the drugs and that these patients require supplemental doses of vitamin D.