A linear regression analysis of the effect of bioelements on acute respiratory infections incidence in preschool children

Abstract

Purpose - to identify the bioelements having the most significant impact on the susceptibility of preschool children to frequent episodes of acute respiratory infections (ARI). Materials and methods. A total of 30 children (14 boys and 16 girls) aged 1-6 years, undergoing inpatient treatment on ARI, were involved in the clinical study. Two integral indicators of acute respiratory infections recurrence, i.e. the infection index and the resistance index, were taken into account for each patient. The children were tested by X-ray fluorescence analysis of 17 bioelements in their hair - Zn, Fe, Cu, Se, Mn, Cr, Co, Br, Ni, Rb, Sr, Sn, Pb, Ca, K, S, and Cl. The statistical processing of the obtained digital material was performed with IBM SPSS Statistics 28 licensed software. A linear regression analysis with stepwise involvement of predictors was applied. Results. In preschool children, there is a moderate negative correlation between hair Rb content and the calculated resistance index (ρ=-0.405; p=0.026; 95% CI: (-0.674)-(-0.042)), according to which lower concentrations of this bioelement are associated with more frequent episodes of ARI. Additionally, Rb has a statistically significant pairwise relationship with several other bioelements studied and the ratios between them. Rb was demonstrated to be directly and most closely correlated with K (ρ=0.842; p<0.001; 95% CI: 0.678-0.926). A prognostic model of the resistance index was obtained, using the linear regression analysis of independent factors. The formula of the prognostic model included only one of the factors studied - the ratio of Mn/Cr content in hair. The informativeness of the mentioned model was 24.9%, which is a quite significant value, taking into consideration a broad range of known predictors for recurrent respiratory infections. Conclusions. The findings are complementary to the available scientific data on the participation of the bioelements in providing resistance to frequent ARI in preschool children. It is planned to continue examining the status of particular bioelements in combination with other potential predictors of recurrent respiratory infections. The study was conducted in accordance with the principles of the Declaration of Helsinki. The study protocol was approved by the local ethics committees of the institutions mentioned in the paper. An informed parental consent was obtained for the study in children. No conflict of interests was declared by the authors.