Ca&Bone - 2007;10(03)

Ca&Bone

SEPTEMBER 11, 2007

[Calcium and vitamin D supplementation in daily practice in view of contraindications]

KOVÁCS LÁSZLÓ

[The current reimbursement regulations that came into effect this summer for the prevention and the treatment of osteoporosis require calcium and vitamin D supplementation in addition to antiporotic agents if appropriate conditions are met. In this paper, the author reviews those conditions that represent contraindications for calcium and vitamin D supplementation. Among these, the extremely rare vitamin D intoxication is mentioned and a detailed list of disorders resulting in hypercalcaemia is given with emphasis on the most common causes such as hypercalcaemia associated with malignancy and primary hyperparathyroidism. With hypercalcuria and renal stone disease, the diet low in calcium appears to have no effect on the outcome; moreover recent studies demonstrate beneficial effect of increased calcium intake, although the optimal calcium and vitamin D supplementation needs further clarification in these conditions. This review highlights the role of additional factors in increasing the risk such as hyperoxaluria, hyperuricosuria, hypocitraturia, as wells as the excessive protein and potassium-chloride intake or the pharmacological differences of various calcium supplements. The article underscores the use of activated vitamin D products in severe renal failure to prevent secondary hyperparathyroidism and renal osteodystrophy. The new regulations represent a significant improvement in the therapy of patients with osteoporosis, however the individualized therapy and follow up, the good relationship between patient and physician contribute to the optimal therapeutic effects and to minimize the side effects.]

Ca&Bone

SEPTEMBER 11, 2007

[Femoral head osteonecrosis in a child with acute lypmhoblastic leukemia]

GÁCS ZSÓFIA, KOVÁCS GÁBOR, HOSSZÚ ÉVA

[INTRODUCTION - The treatment of pediatric leukemia has become increasingly successful, with a survival rate over 80%. Thus interest has been increasingly focused on the long-term side-effects of the treatment. The questions of reduced fertility rate, occurance of second malignancies, cardiomyopathy, impaired renal and pulmonal function have been extensively studied. Changes of bone metabolism in connection with the disease itself and the treatment have been analysed in the past decade. CASE REPORT - We present the case of a 15-year-old boy with acute lymphoblastic leukemia, who had bone pain soon after the diagnosis. During the course of chemotherapy his complaints were fluctuating, and he developed severe osteoporosis. The level of a bone resorption marker, β-CrossLaps, was elevated. In the second year of therapy an acute pain of the left hip occured with fever and restriction of joint movement, which was diagnosed and treated as osteomyelitis. A few months later avascular necrosis of the left femoral head was revealed. Both pharmaceutic (calcium, vitamin D, calcitonin, bisphophonate) and orthopedic treatment were used, as a result bone mineral density and movement restriction improved; his leukemia is now in remission. CONCLUSIONS - The factors influencing bone metabolism in leukemic children are reviewed. Firstly the effects of malignant cells on bone mineral content are analyzed, then the chemotherapeutic drugs’ mechanisms of action are examined extensively. The direct and indirect effects of secondary factors (hospitalization, immobility, lack of sun exposure, malabsorption, immunsuppression, peripheral neuropahty) are also analyzed. The advantages and disadvantages of drugs used in preventing and treating childhood osteopenia are reviewed.]