Longitudinal changes in body mass index Z- scores during infancy and risk of childhood allergies

Background: Few studies address the dynamic changes of body mass index (BMI) Z -scores during infancy with breastfeeding and their impact on childhood atopic diseases.Methods: A total of 183 children from a birth cohort regularly followed-up for 4 years were enrolled in this study. Time series data of BMI Z-scores from 1 month to 2 years of age was clus-tered using K-means method in R software. Breastfeeding status during the first 6 months of life was recorded and classified. The total serum and specific immunoglobulin E (IgE) levels to food and inhalant allergens were measured at age 0.5, 1, 1.5, and 2 years.Results: Using K-means clustering, the dynamic changes in BMI Z-scores were classified into three clusters (cluster A, increasing, n = 62; cluster B; decreasing, n = 62; cluster C, constant low, n = 59). Despite having no statistical association with atopic diseases, a decreasing trend in infantile BMI Z-scores was significantly associated with a higher prevalence of IgE sensitization at age 1 which increased the risk of rhinitis development at age 4 (P = 0.007). No difference in BMI Z-scores was determined between different breastfeeding patterns. Howev-er, exclusive formula feeding >= 6 months was found to be significantly associated with mite sensitization at age 1.5 years which risks asthma development at age 4 (P = 0.001).Conclusions: A decreasing trend of BMI Z-scores during infancy is determined to be inversely associated with IgE and allergen sensitization, which may potentially increase the risk of al-lergies in early childhood. Copyright 2021, Taiwan Society of Microbiology. Published by Elsevier Taiwan LLC. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

The dynamic changes in BMI Z-scores during infancy are associated with atopic diseases, with a decreasing trend increasing the risk of IgE sensitization at age 1 and subsequent development of rhinitis at age 4. Exclusive formula feeding for over 6 months is significantly associated with mite sensitization at age 1.5 and risks asthma development at age 4.