Effect of serum calcidiol on the course and outcomes of bronchopulmonary dysplasia in children

Background. The multifaceted effects of vitamin D (VD) on the inflammation system have attracted particular attention of researchers. It is known that VD is involved in the activation of monocytes, stimulation of cellular and humoral immunity; at the same time, it has an indirect ability to bind extracellular actin and endotoxin. The variety of immunological interference makes it possible to consider the VD status as a candidate factor influencing the transformation of the clinical picture of bronchopulmonary dysplasia (BPD) and variants of the disease outcomes. Objective. Determination of the clinical significance of changes in serum calcidiol levels on the course and outcomes of BPD in children. Methods. According to the study design, 146 children with BPD were examined at the stage of revision of the diagnosis due to age-related transformation, and 92 children of the same age, born prematurely, but did not develop BPD were included in comparison group. The complex of examinations included general clinical and instrumental research methods in accordance with the standard of medical care. The severity and form of BPD in patients were determined according to the working classification of clinical forms of bronchopulmonary diseases in children. Determination of the serum total hydroxycalciferol level was carried out by the enzyme-linked immunosorbent assay using test systems from ZAO TechSystems. Taking into account the normal distribution of the variables, the statistical analysis was carried out using the parametric statistics. Results. According to the results obtained, VD insufficiency was registered statistically significantly more often in the main cohort of patients, while reference values were determined in the comparison group. Reference VD values were identified in 54.9% of children in the comparison group; in other cases, a decrease in the serum calcidiol level of varying degrees was noted, namely, VD deficiency (27.5%) and insufficiency (17.6%). According to the statistical analysis, VD deficiency was associated with a variant of the severity of the course of the disease. Namely, children with deficient values were statistically significantly more likely to have a severe form, while with reference values and a level corresponding to deficiency - a moderate BPD course. A comparative analysis of the frequency of respiratory infections in children with BPD revealed that ARVI episodes were significantly more often recorded with VD deficiency - more than 8 times a year, while with reference values - no more than 5 times a year. VD deficiency was associated with the development of chronic lung diseases as outcomes in children with BPD, while with reference values, recovery or recurrent bronchitis were statistically significantly more frequent. Conclusion. An association between the VD status of children with BPD at the stage of diagnosis revision with the severity of the course, the frequency of respiratory infections, and variants of the disease outcome was revealed.

bronchopulmonary dysplasia, children, disease outcomes, vitamin D