Diagnosed Changes of Bone Mineral Density and Level of Calciotropic Hormones in Juvenile Hyperthyroidism

Abstract In childhood and adolescence, a genetically determined bone mass accumulates, which ensures the strength of the skeleton throughout life. But with thyrotoxicosis, a separation of the processes of bone resorption and synthesis and the formation of sites of osteoporosis and osteosclerosis occur, leading to the loss of 10% of bone mass in 1 cycle of remodeling. Because of the lack of information about this phenomenon, our work aimed to study the state of bone mineral density and levels of calciotropic hormones in children and adolescents with thyrotoxicosis. The study was conducted by 19 children and adolescents with thyrotoxicosis. The control group consisted of 23 healthy children and adolescents. All studies were conducted in the RSSPMCE. Thyroid status, PTH and vitamin D were determined using a closed-type immunochemistry analyser Cobas e 411 Hitachi company HoffmanLeRoche (Switzerland) and its reagents. Bone mineral density was evaluated by dual-energy absorptiometry on a Stratos X-ray densitometer from DMS, France. The results of the study showed that the average value of the level of vitamin D in the group with thyrotoxicosis was 12.3 ± 1.1 ng/ml, against 20.4 ± 6.2 ng/ml of the control group, while its deficiency was diagnosed in 84.2%, and its insufficiency - in 15.8% of pediatric patients. In the group with thyrotoxicosis, the average level of PTH was lower and amounted to 45.1 ± 23.9 ng/ml (p < 0.05) compared with the control (49.2 ± 21.3 ng/ml); hypoparathyroidism was found in 4.9 times more often than among healthy children, and 21.1% showed an increase in the level of PTH. In children and adolescents with thyrotoxicosis Z- index of the femoral neck, lumbar vertebrae and the general body were significantly lower than in the control group. 36.8% of children with thyrotoxicosis have osteoporosis. Conclusion: Thyrotoxicosis in children and adolescents causes a decrease in BMD and majorly increases the development of osteoporosis.