The thesis deals with the improvement of the prevention and treatment of gastroesophageal reflux diseases (GERD); in children with nasopharyngeal signs. For the study, 88 children were examined; during clinical-anamnestic and instrumental studies (daily pH monitoring in the esophagus), they were divided into four groups: group 1 (main group) comprised 22 children (mean age-4,14±0, 25 years), diagnosed with GERD with nasopharyngeal signs; group 2 included 22 children (mean age-4,14±0,19) with chronic ENT pathology without GERD; group 3 contained 22 children (mean age-4,8±0,25) with GERD without ENT signs, the control group (group 4) consisted of 22 children without pathology of the gastrointestinal tract (GIT) and ENT organs. Children with GERD with nasopharyngeal signs have GERD-specific complaints, namely abdominal and chest pain (63,6%), belching (54,5%), "wet spot" symptom (86,4%) and sleep disturbances (68,2%), as well as coughing after eating and morning hoarseness, which in addition to laryngeal hyperemia and edema of the vocal cords may indicate laryngopharyngeal reflux (LFR).Children who have GERD with nasopharyngeal signs present with grade 3 tonsil hypertrophy (81,8%), more frequent episodes of stomatitis, common carious lesions of tooth enamel, mappy tongue, plaque and tooth marks on the tongue. In addition, these children suffer from ARI significantly more often than children with GERD without ENT signs and need treatment with antibacterial drugs more often than children with chronic ENT pathology without GERD. A feature of children with GERD is a history of frequent and profuse vomiting in the first months of life. Besides, children with nasopharyngeal signs of GERD present with rickets and belateddentition (after a year), which may be associated with insufficient vitamin D intake. It was found that the deficiency of vitamin D in pregnant women, and subsequent deficiency of vitamin D in childrenin general and after the first year of life increases the risk of developing GERD with nasopharyngeal signs in 3,51 and 3,99 times, respectively. It was found that all children with GERD with nasopharyngeal signs and most children with chronic ENT pathology without GERD have vitamin D deficiency, while 91,0% of children with GERD without nasopharyngeal signs demonstrate insufficient vitamin D level. The analysis of levels of vitamin D metabolites in blood serumdemonstrated that children with nasopharyngeal signs of GERD had lower 25(OH)D3levels (13,3 (11,6; 14,9) ng/ml than children in other study groups (group 2-17,6 (16,7; 18,9) ng/ml, group 3-21,6 (20,3; 22,9); group 4-24,6 (22,8; 28,2) ng/ml. According to the results of the study of α defensins content in the serum, it was found that children with nasopharyngeal signs of GERD have the lowest levels of α defensins 1-3 in the blood serum (2535,0 (1950,0; 3120,0) pg/ml) in contrast to other groups and control group. A study of LL-37 content in the serum of the observed children also showed its decrease in children with nasopharyngeal manifestations of GERD (17,9 (5,8; 33,3) ng/ml vs. 36,6 (34,6; 40,9) ng/ml of the control group). In children of other study groups, the indicators were higher than in children of the control group. Under conditions of reduced serum vitamin D levels, the adequate immune response is not fully activated, which leads to a decrease in the body's inflammatory immunoreactivity and makes one of the reasons for the more severe course of the disease. Contamination of the faucial and nasal mucous membranes in children with nasopharyngeal signs of GERD is represented by pathogenic microflora (95,5%) with a predominance of Haemophilus influenza. Treatment of children with nasopharyngeal signs of GERD by addingvitamin D3 (2,000 IU/day) to basic therapy during 30 days led to a more rapid regression of such symptoms as cough after eating and morning hoarseness. Prophylactic intake of vitamin D3 at a dose of 1000 IU/day daily from September to April, including a break for May-August, significantly reduced the number of exacerbations of chronic ENT pathology, the number and duration of ARI episodes, the number of antibacterial therapy courses in the development of ARI bacterial complications and their duration than in the control group children. Periodic gastrointestinal complaints during the year were noted only in 18.2% of the main group children, which is 4 times less than in children of the control group. For the first time, the content of endogenous antimicrobial peptides in preschool children with nasopharyngeal signs of GERD, taking into account the vitamin D sufficiency. For the first time, the clinical effectiveness of inclusion of vitamin D3 in the basic therapy and prevention of GERD with nasopharyngeal signs has been proven. The additional administration of vitamin D in the basic treatment of preschool children with GERD and nasopharyngeal signshas been proposed and substantiated.
