Obesity-related asthma in children and adolescents

Abstract

There is substantial epidemiological and experimental evidence of an obesity-related asthma phenotype. Compared to children of healthy weight, children with obesity are at higher risk of asthma. Children with obesity who have asthma have greater severity and poorer control of their asthma symptoms, more frequent asthma exacerbations, and overall lower asthma-related quality of life than children with asthma who have a healthy weight. In this Review, we examine some of the latest evidence on the characteristics of this phenotype and its main underlying mechanisms, including genetics and genomics, changes in airway mechanics and lung function, sex hormone differences, alterations in immune responses, systemic and airway inflammation, metabolic dysregulation, and modifications in the microbiome. We also review current recommendations for the treatment of these children, including in the management of their asthma, and current evidence for weight loss interventions. We then discuss initial evidence for potential novel therapeutic approaches, such as dietary modifications and supplements, antidiabetic medications, and statins. Finally, we identify knowledge gaps and future directions to improve our understanding of asthma in children with obesity, and to improve outcomes in these susceptible children. We highlight important needs, such as designing paediatric-specific studies, implementing large multicentric trials with standardised interventions and outcomes, and including racial and ethnic groups along with other under-represented populations that are particularly affected by obesity and asthma.

Figure 1:. Obesity-related asthma and underlying pathways

Adapted from Forno and Celedón. Blue = omics (genomics, microbiome, and immune) changes. Green = dietary and nutritional factors. Red = metabolic and inflammatory effects.

Figure 2:. Immune and metabolic mechanisms in obesity-related asthma

HDL = high-density lipoprotien. Il-6 = interleukin 6. ILC3 = type 3 innate lymphoid cells. LDL = low-density lipoprotien. Th1 = T helper 1 cell. Th2 = T helper 2 cell.

Figure 3:. Pathways to improving outcomes in obesity-related asthma

Proposed approaches and pathways to improve the diagnosis and management of paediatric patients with obesity and asthma. Blue = direct interventions. Green = changes as consequence of direct interventions. Red = non-interventions but rather, clinical and research improvements.