Adipokines in Obese Asthma: A Complex Relationship Influenced More by Sex, Weight, and Oral Steroid Treatment Than Disease Severity.

BACKGROUND

Obesity-related asthma (OBA) is a distinct asthma phenotype, with increased severity. Adipokine release from excessive adipose tissue is suggested to be a key feature of OBA pathophysiology. However, it is unclear how the clinical characteristics of severe asthma associate with adipokine mediators. We examined systemic adipokine levels and evaluated relationships with disease severity, weight, sex, and steroid treatment in asthma.

METHODS

A multiplex immunoassay for nine adipokines with proposed involvement in obesity-related inflammation (adiponectin, adipsin, BAFF, chemerin, FGF-21, leptin, lipocalin-2/NGAL, osteonectin and resistin) was designed. Plasma adipokines were measured in 127 patients with mild-to-moderate asthma (MMA) or severe asthma (SA) from the European BIOAIR cohort at baseline and after a controlled 2-week oral corticosteroid (OCS) intervention.

RESULTS

Leptin and chemerin were significantly increased in patients with SA vs. MMA. Leptin, adiponectin, adipsin, and NGAL were affected by sex, whereas leptin and adipsin were strongly affected by weight. OCS increased leptin and adiponectin, decreased adipsin and BAFF, and did not affect osteonectin, resistin, or chemerin. No adipokines showed positive associations with exhaled NO, blood or sputum eosinophils, although certain correlations with serum CRP, blood, and sputum neutrophils were observed.

CONCLUSIONS

Overall, we observe variable relationships between the nine adipokines, obesity and asthma severity. There were no relationships between adipokine levels and type-2 airway inflammation, yet associations with systemic neutrophilic inflammation were seen. Although one adipokine, chemerin, was independently associated with asthma severity, deciphering the role of adipokines in OBA is complex due to the influence of sex, BMI, and OCS.