STRUCTURAL AND FUNCTIONAL BONE FEATURES IN CHILDREN RESIDING IN THE RADIOLOGICALLY CONTAMINATED TERRITORIES OF UKRAINE.

Objective: Evaluation of structural features and metabolic/biochemical abnormalities of the bone tissue and relevant regulation patterns in children, residing in the radiologically contaminated territories (RCT).

Materials and methods: Children (n = 148) aged 7 to 18 years old were involved in the study. Bone mineral density (BMD) is given in 3 grades according to the mean square deviation values, namely Grade I - standard (n = 75),Grade II - reduced (n = 45) and Grade III - very low one (n = 28). Cholelithiasis, urolithiasis, cancer and endocrinediseases, as well as bone fractures in the family members of children were taken into account. Bone fractures in thehistory and jaw anomalies were evaluated in study participants. A spectrum of blood biochemical parameters, namely the serum content of total protein, alkaline phosphatase (APh), serum iron (SI), creatinine, calcium, vitamin D,parathyroid hormone, calcitonin, pituitary thyroid stimulating hormone (TSH), free thyroxine (FT4), and cortisolboth with urine content of amino acids were assayed. Radiation doses in study participants were calculated.

Results: Abnormalities of the bone organic component were diagnosed according to the reduced serum level of creatinine, decreased urine levels of glycine and lysine, and increased urine content of oxyproline. A direct relationshipwas established between the urine level of oxyproline and serum TSH content (r = 0.42; p < 0.05). Abnormalities inthe bone mineral component were accompanied by calcium deficiency, increased serum content of APh anddecreased BMD. A direct relationship was established between the serum levels of calcium and APh (r = 0.33) andan inverse one between the APh serum content and BMD (r = -0.60) (р < 0.05). An inverse relationships were established between the serum vitamin D content and APh activity (r = -0.34), between the serum levels of vitamin D andSI (r = -0.35) (р < 0.05). Incidence and patterns of the abnormal parameters depending on BMD grades were established. Biochemical parameters reflecting the state of bone organic and mineral components both with the level ofserum iron and hormonal regulation of bone formation were ranked. Individual radiation doses of children were(0.66 ∓ 0.04) mSv being not correlated with any other studied parameters.

Conclusions: Evaluation of the structural and functional components of bone tissue sheds light on the mechanismsof bone formation processes, metabolism of biochemical cascade, and regulatory pathways aiming the timely correction of abnormalities.