The Influence of Body Mass Index on Monocytes and Eosinophil Levels and Their Relationship With Spirometric Parameters in Children and Adolescents With Bronchial Asthma

<b>Objectives:</b> Excess adipose tissue induces low-intensity inflammation, which is an important pathogenetic factor adversely affecting the course of bronchial asthma (BA) in overweight/obese patients. The key effector cells of this inflammation are monocytes and macrophages. However, there are currently no studies characterising the effect of body mass index (BMI) on peripheral blood monocyte levels in children and adolescents with BA and their relationship with spirometric parameters reflecting bronchial patency. The aim of this study was to investigate the effect of BMI on peripheral blood monocyte and eosinophil levels and their relationship with spirometric parameters in children and adolescents with asthma. <b>Methods:</b> A single-centre, observational cross-sectional study was conducted. A total of 212 patients with asthma aged 7-17 years were studied. Anthropometric and spirometric parameters and the cellular composition of peripheral blood were evaluated. The children were divided into two groups: Group 1: with normal body weight (BW) and Group 2: with overweight/obesity. <b>Results:</b> In overweight/obesity patients, the number of peripheral blood monocytes (0.62 ± 0.19) was significantly higher compared to the group of normal weight patients (0.54 ± 0.15, <i>p</i> < 0.001). In contrast, eosinophil levels were statistically lower in the overweight/obesity group (0.22 [0.12; 0.42]) than in the normal weight patients (0.30 [0.14; 0.56], <i>p</i> = 0.039). A statistically significant negative correlation was found between the absolute number of monocytes and z FEV1/FVC, z MMEF_25-75 in the overweight/obesity group (<i>R</i> = -0.32, <i>p</i> = 0.005, <i>R</i> = -0.30, <i>p</i> = 0.007, respectively) and a statistically significant negative correlation between eosinophil count and z FEV1/FVC, z MMEF25-75 in normal weight patients (<i>R</i> = -0.20, <i>p</i> = 0.021, <i>R</i> = -0.22, <i>p</i> = 0.010, respectively). <b>Conclusions:</b> The results obtained may indicate a modifying effect of overweight/obesity on inflammation endotypes in children and adolescents with BA.