Adult but not childhood onset asthma is associated with the metabolic syndrome, independent from body mass index

Abstract

Introduction: Adult-onset asthma (AOA) is usually more severe compared to childhood onset asthma (CoA). Given the increasing evidence that AoA is associated with obesity, we investigated the relationship of other related metabolic comorbid conditions with AoA compared to CoA.

Study design and methods: This cross-sectional study compared the metabolic syndrome and lipid derived inflammatory markers in patients with AoA, CoA and age- and sex-matched control subjects without asthma. Participants were asthma patients visiting the outpatient clinic of two teaching hospitals in Rotterdam, The Netherlands. All participants underwent lung function tests, blood tests and physical activity tracking. AoA was defined as asthma age of onset after the age of 18 years. Metabolic syndrome was defined according to the international joint interim statement criteria.

Results: Eighty-one participants were included (27 AoA, 25 CoA, 29 controls). AoA was associated with the metabolic syndrome (Odds Ratio = 3.64 95% CI (1.16-11.42) p = 0.03, Nagelkerke R² = 0.26), adjusted for age, sex, body mass index and smoking habits. AoA patients had higher median serum IL-6 and leptin-adiponectin (LA) ratio compared to controls (IL-6 (pg/mL): 3.10 [1.11-4.30] vs. 1.13 [0.72-1.58], p = 0.002 and LA ratio (pg/mL): 6.21 [2.45-14.11] vs. 2.24 [0.67-4.71], p = 0.0390). This was not observed in CoA and controls.

Conclusion: AoA was associated with the metabolic syndrome and its related pro-inflammatory endocrine and cytokine status. This may suggest adipose tissue derived inflammatory markers play a role in the pathophysiology of AoA.

Keywords: Adult-onset asthma; Asthma; Inflammation; Lipid mediators; Metabolic syndrome.