What the Genetic Background of Individuals with Asthma and Obesity Can Reveal: Is β2-Adrenergic Receptor Gene Polymorphism Important?

The goal of this review was to evaluate the association of β2-adrenergic receptor ( ADRB2 ) gene polymorphisms with asthma and obesity. Asthma is the most common pediatric inflammatory disorder. The prevalence, severity, and hospitalization index for asthma have increased markedly in the last several decades. Interestingly, asthma is often diagnosed along with obesity. Genetic factors are essential for both conditions, and some of the candidate pleiotropic genes thought to be involved in the development of these diseases are ADRB2 , vitamin D receptor ( VDR ), leptin ( LEP ), protein kinase C alpha ( PRKCA ), and tumor necrosis factor alpha ( TNFα ). The ADRB2 has been studied in multiple populations and more than 80 polymorphisms, mainly single-nucleotide polymorphisms, have been identified. For nonsynonymous Arg16Gly, Gln27Glu, and Thr164Ile, functional effects have been shown. In vivo , these polymorphisms have been evaluated to determine their association with both obesity and asthma, but the results are inconsistent and depend on the population studied or how the disease was defined. Currently, there are only few reports describing the genetic background for the comorbidity of asthma and obesity.