Association of Childhood Obesity and the Immune System: A Systematic Review of Reviews.

The growing prevalence of childhood obesity has become a serious health problem over the past decades. As the immune system is greatly affected by excess weight, in this review of reviews, we discuss the findings of review articles about the relationship between childhood/maternal obesity and children's immune system. We searched English-language articles in PubMed, Scopus, ISI Thomson Reuters, and Google Scholar databases. All relevant reviews, either systematic or narrative, were retrieved. Then their quality was assessed by using the Assessment of Multiple Systematic Reviews and International Narrative Systematic Assessment tools, respectively. In the final step, 26 reviews were included. Our review suggests that childhood obesity is associated with extensive changes in the serum levels of inflammatory and anti-inflammatory cytokines and proteins, as well as the number of immune cells and their behavior. Therefore, it might cause or exacerbate diseases such as asthma, allergy, atopic dermatitis (AD), and obstructive sleep apnea syndrome. Moreover, childhood obesity may reduce the immune system responsiveness to vaccines and microorganisms. Furthermore, studies suggest that maternal obesity increases the risk of asthma in offspring. Future studies are needed to determine different associations of childhood obesity with allergy, atophic dermatitis, and autoimmune diseases.