Skeletal turnover and total body elemental composition during extended calcitonin treatment of Paget's disease

Radiological demonstration of healing in Paget's disease of bone treated with APD

Twenty-three patients with Paget's disease received the bisphosphonate APD and were examined radiologically every 6 months. Because routine roentgenographic procedures were followed, a number of the X rays were not fit for comparison. The radiographic technique, as well as the positioning of the patients, is critical since both could lead to artefacts. All patients reached normal biochemical levels, usually within 6 months. Out of the 23 patients 11 showed definite radiological improvement in one or more lesions; probable improvement was seen in another three. Of the 65 individual lesions, with films that were comparable, 30% definitely and 20% probably improved; 50% did not change but deterioration was never encountered. Osteolytic lesions in the long bones are most suitable for the evaluation of radiological changes and follow-up of these lesions during treatment should be most rewarding.

Intravenous clodronate in the treatment and retreatment of Paget's disease of bone

The effects of short courses (5 days) of intravenous clodronate 300 mg daily were studied in 31 patients with active Paget's disease of bone. The diphosphonate induced a striking reduction in biochemical indices of disease activity, which was sustained for at least 6 months after withdrawal of treatment. Apparent resistance to further treatment in patients previously treated for Paget's disease was an artefact due to incomplete relapse before retreatment. There was no significant difference in the degree of suppression of alkaline phosphatase activity between patients given intravenous clodronate and 45 patients given clodronate 1.6 g daily by mouth for 6 months. Short-term intravenous clodronate provides a useful alternative strategy for the treatment of patients with Paget's disease.

Sodium excess in postmenopausal osteoporosis

The sodium excess (Naes) which represents the nonexchangeable sodium compartment of bone was calculated from the total body sodium and total body chlorine of 95 women with vertebral crush fracture syndrome. No evidence was found for a subpopulation with increased or decreased Naes or Naes:TBCa ratio (TBCa is total body calcium which reflects total skeletal mass). Correlations in the osteoporotic women were found between the Naes and serum alkaline phosphatase (r = 0.31), PTH (r = 0.53), urinary hydroxyproline excretion (r = 0.42) and serum 250H vitamin D (r = -0.32). These data suggest that the state of vitamin D nutrition as well as parathyroid hormone levels may influence the quantity of sodium in bone in osteoporotic women. It is of great interest that these relationships were not observed in two control populations consisting of elderly women and women who recently underwent spontaneous menopause.

Lithium effects on calcium, magnesium and phosphate in man: effects on balance, bone mineral content, faecal and urinary excretion

Calcium, magnesium and phosphate metabolism was studied in lithium-treated patients, using a metabolic balance technique. Two groups of patients participated in the study: 1) Patients who were to start on a prophylactic lithium treatment, and 2) Long-term lithium-treated patients whose treatment was to be terminated. Lithium treatment produced a positive balance in both calcium, phosphate and magnesium. By continuous lithium treatment the effect on magnesium wore off, whereas the effect on calcium and phosphate persisted. In urine, lithium induced a decrease in both calcium and phosphate excretion, whereas the excretion of magnesium was increased. Bone mineral content was measured by photon absorption, and lithium treatment resulted in a decrease in bone mineral content occurring within the first 6 months of lithium treatment. In the patients, bioavailability of the Li2CO3 preparation was found to be about 95%, and the patients contained about one 24-h dose of lithium just before the next dose of lithium was administered.

Long-term measurement of skeletal and lean body mass in Paget's disease of bone treated with synthetic human calcitonin

Total body calcium (an index of skeletal mass), ulnar bone density, and total body potassium (lean body mass) were followed for up to 5 years in 38 patients with Paget's disease during treatment with synthetic human calcitonin. Calcium was measured by neutron activation, ulnar density by X-ray photodensitometry, and potassium by counting its natural 40K radioactivity. There was a significant rise in total skeletal mass in a group of 8 patients in the 12 months following the start of therapy, but overall, total bone mass and ulnar density remained constant during treatment. Small mean losses of body potassium were observed (approximately 4%) after several years elapsed on treatment. Over an average period of 12 months after discontinuation of therapy in 21 patients there was no significant mean change in calcium or potassium. The means of the ratios of total body calcium divided by predicted normal calcium (over the whole period of measurement) were 1.08 (males) and 0.99 (females) and were not significantly different. Comparison of the ulnar densities of patients and normal subjects gave similar results. The average ratio of measured to predicted normal potassium was 1.13 (both males and females). Thus there was no indication of depletion in skeletal mass below normal either in the untreated disease or resulting from treatment.

Bone turnover in Paget's disease: biochemical and kinetic measurements during salmon calcitonin therapy

A comparison of calcium-47 kinetics and biochemical measurements has been made in 25 previously untreated patients with Paget's disease. The rate of disappearance of 47Ca into bone with a turnover time of more than 5 days was measured as A5, and the pool size with a turnover time of less than 5 days as E5. In moderately active disease the reductions in A5 and E5 to be anticipated from treatment seem to be offset by an increase in exchangeability due to remineralization of osteoid. In more active disease the effect of calcitonin may be to shift bone formation from a woven to a lamellar pattern as well as to reduce turnover. Under these circumstances both A5 and E5 are reduced by treatment more in keeping with biochemical changes.

Influence of parathyroid hormone and calcitonin on tissue zinc homeostasis in the rat

Tissue zinc accumulation kinetics and compartmental analysis models were evaluated in thyroparathyroidectomized (TPTX) rats treated with parathyroid extract or calcitonin. The animals were injected with 65Zn and studied at multiple time intervals. SAAM-25 was utilized to generate models from the plasma specific activity decay curves. Calcitonin had a marked effect to decrease the fractional influx and efflux transfer coefficients in the model and inhibit tissue zinc accumulation in several, but not all, tissues. Parathyroid extract increased accumulation in all tissues studied, but had minimal effects on the model. It is concluded that parathyroid hormone acts nonspecifically and that calcitonin appears to have specific influences on zinc homeostasis.

Paget's disease and the nervous system

Paget's disease usually is found in patients past the age of 40. Early presenting symptoms include headache, deafness, tinnitus, and pain due to radicular compression. The diagnosis is confirmed by radiographic features and elevated levels of serum alkaline phosphatase and urinary hydroxyproline. Bony overgrowth results in pressure on nearby soft tissues such as the brain, spinal cord, and certain peripheral nerves. The abnormally soft quality of the calvarial bone permits distortion by the weight of the brain. Dorsal inclination of the plane of the foramen magnum and the projection of the odontoid process into the posterior fossa lead to stretching of the brain stem over the odontoid process and the ventral margin of the foramen. Obstructive hydrocephalus may result. Sarcoma of the crainial vault may develop in cases of Paget's disease. Once cervicomedullary or spinal compression has occurred, surgical decompression may be necessary. Three drugs--calcitonin, disodium etidronate, and mithramycin--have been used with some benefit in the treatment of Paget's disease.

Calcitonin therapy of children with osteogenesis imperfecta

Two children, ages 13 2/12 and 6 6/12 years, with osteogenesis imperfecta were treated with salmon calcitonin. During the course of therapy the older child developed calcitonin dose-related hypomagnesemia on two occasions. The younger child, coincident with otitis media and vomiting, developed hypomagnesemia, hypophosphatemia, hyponatremia, and hypokalemia. Since rib biopsies obtained before and after one year of treatment with salmon calcitonin failed to demonstrate any histologic changes, therapy was discontinued because of the induced metabolic consequences of calcitonin therapy.

Total body sodium and chlorine in normal adults

Absolute levels of total body sodium (TBNa) and total body chlorine (TBCl) were determined in 81 normal adults (39 males, 42 females) by means of total body neutron activation analysis (TBNAA). The ages of the subjects ranged from 30 to 90 yr. The mean values for both TBNa and TBCl remained relatively constant throughout the age span studied for males, but decreased slightly for females over 60 yr of age. In order for the absolute measurements of Na and Cl to be of clinical value, the values must be compared to a predicted value based on the sex and body habitus of the individual. Normalization of TBNa values relative to body dimensions (weight, height, body surface area) were evaluated. In addition, TBNa was related to total body calcium (TBCa), which reflects skeletal mass, and TBK, which reflects muscle, or lean body mass. Normalization in terms of a linear combination of the TBCa and TBK was found to be the most satisfactory of all those studied. Sodium excess, NaES, defined as the amount of body sodium (mEq) in excess of body chlorine (mEq) was determined. Sodium excess correlated well with total body calcium. Values for total body sodium and chlorine obtained in the present study were compared with values previously reported in the literature.