Bone mineral content (BMC) was determined by photon absorptiometry on both forearms in 28 patients with myelomatosis. Nineteen patients had received intermittent treatment with cytostatic agents and prednisone. No significant reduction of BMC was found between the patients with myelomatosis and an age- and sex-matched normal population. Neither was any significant decrease in BMC with the duration of the disease demonstrated. In 16 patients, routine X-ray indicated osteoporosis, but their BMC was not reduced compared to the patients without osteoporosis on X-ray. However, the former patients were significantly older than the latter. Provided the term "generalized osteoporosis" implies reduced mineral content in all bones, the study indicates that patients with myelomatosis have not generalized osteoporosis.

Thirty-one patients scheduled for long-term (24 weeks) treatment with prednisone in comparatively high doses were randomly allocated to two further treatment groups. Group A received prednisone plus 'triple-treatment' (vitamin D2 45000 iu twice weekly, sodium fluoride 50 mg and calcium phosphate 4.5 g daily), group B received only prednisone. The study was undertaken in order to evaluate the effect of prednisone- and triple-treatment upon bone mineral content (BMC) and vitamin D metabolism. The groups were comparable with regard to age, sex and prednisone dose. BMC fell rapidly and similarly in both groups, demonstrating that the triple-treatment has no preventive effect on corticosteroid induced osteopenia. Serum concentrations of 25OHD2, 25OHD3 and 1,25(OH)2D were unchanged in group B (without triple-treatment), whereas in group A 25OHD2 increased enormously, 25OHD3 was suppressed possibly by substrate competition for hydroxylation in the liver and 1,25(OH)2D was halved. The suppression of 1,25(OH)2D may be an effect of raised 25OHD2 alone, or in combination with corticosteroid excess.

ABSTRACT To evaluate changes in bone composition during treatment with corticosteroids, the bone mineral content (BMC, measured by photon absorptiometry) and the degree of bone mineralization (measured as the bone phosphorus/hydroxyproline ratio) were determined in 18 patients during prednisone treatment for haematological and connective tissue diseases. The prednisone dose ranged from 12 to 51 mg/day (mean 27). The BMC decreased significantly (mean 2.5%) during the studied 12 weeks of treatment, but the change did not correlate significantly to the prednisone dose. The degree of bone mineralization remained unchanged, indicating equal losses of mineral and of collagen in bone during prednisone treatment. The changes correspond to a rapidly developing osteoporotic state.