FEATURES OF BONE METABOLISM UNDER THE CONDITIONS OF DIETARY-INDUCED ZINC DEFICIENCY IN THYROID, CARBOHYDRATE HOMEOSTASIS DISORDERS AND OBESITY

Abstract

Periodontal tissue diseases are prevalent in the adult population of Ukraine and reach 90%. Among the causes of their development are inflammatory processes of various genesis, oxidative stress, metabolic disorders, endocrine pathology, and microelement imbalance. Purpose of the study. To study in an experiment the features of bone metabolism, energy supply and distribution of bioelements in the blood and periodontal tissues under conditions of diet-induced zinc deficiency against the background of thyroid and carbohydrate homeostasis disorders and obesity. Material and methods of the study. The studies were conducted on 100 white outbred sexually mature male rats (150–180 g), which were fed a standard diet (control group), zinc and iodine-deficient diets, high-carbohydrate or highfat feeding for two months. The content of zinc, calcium and magnesium was determined in the cementum of the tooth root, the alveolar process and part, and the erythrocyte mass. The state of bone metabolism, energy supply, thyroid status and carbohydrate metabolism were assessed in the animals, and the body mass index was determined. Results of the study and their discussion. As a result of the study, in rats of all experimental groups, a decrease in the content of zinc, calcium and magnesium in the erythrocyte mass was established relative to the values in intact animals. In rats that were on a zinc-deficient diet, in the cementum of the tooth root and the alveolar process and part, a significant decrease in the content of zinc (by 27.28 and 53.67%) and an increase in the concentration of magnesium (by 2.81 times and by 12.45%, respectively) relative to the control were found. Under conditions of iodine-deficient and highcalorie diets, a decrease in the content of zinc (by 44.35–56.17%), calcium (by 71.96–91.69%), magnesium (by 86.28–92.52%) relative to the initial values was observed in the alveolar process and part. In the cementum of the tooth root under conditions of iodine deprivation and a high-carbohydrate diet, the level of zinc and magnesium increased, but the calcium content decreased, and under a high-fat diet, the concentration of zinc and calcium decreased, but magnesium increased. Against the background of microelement imbalance, an increase in the activity of acid phosphatase (by 36.13–88.53%) and inhibition of alkaline phosphatase (by 17.98–51.68%) in the blood serum were established. Under the studied conditions, the activity of succinate dehydrogenase and lactate dehydrogenase decreased, but malate dehydrogenase was activated (only after high-calorie feeding). The detected diet-induced changes in the hormonal profile (hypothyroid dysfunction, insulin resistance and obesity) are a risk of progression of periodontal tissue lesions. Conclusion. Zinc deficiency diet is accompanied by redistribution of zinc, calcium and magnesium in periodontal tissues, affects the dynamic balance of re-/demineralization of tissues of the dento-maxillary system, disrupts energy supply processes. Such changes are a trigger of the inflammatory process, significantly affect the formation of dental plaque and tartar formation. Zinc deficiency causes the development of hypothyroid dysfunction, insulin resistance and weight gain, which increases the risk of developing dental pathology. One of the links in the damage to periodontal tissues in conditions of hypothyroidism, diabetes mellitus and obesity may be a violation of the zinc balance, which stimulates the progression of the inflammatory process, oxidative stress, changes in bone metabolism processes and the development of destructive processes.