Independent and synergistic associations of asthma and obesity with systemic inflammation in adolescents

Introduction. Both asthma and obesity often occur in the same individual. Each increases the risk of cardiovascular disease (CVD) with systemic inflammation likely playing a vital role. We examined the independent and synergistic associations of asthma and obesity with systemic inflammation using high-sensitivity C-reactive protein (hs-CRP) levels in adolescents. Methods. This study involves the cross-sectional design carried out in the adolescent and respiratory medicine practices in a children's hospital. Out of 124 adolescents (mean age 16.1 ± 2.3 years), who were either of obese (N = 75) or of normal weight (N = 49). 51 had asthma (18 normal weight and 33 obese). Results. hs-CRP levels were higher in obese versus normal weight groups (geometric mean ± SD: 2.38 ± 2.91 vs. 0.72 ± 3.54; p < .001), and in the asthmatic versus non-asthmatic groups (geometric mean ± SD: 1.21 ± 3.71 vs.1.96 ± 3.28; p = .039). We found a trend of increasing hs-CRP levels across the four groups (p < .001), with the obese asthmatic group having the highest level. In multivariate regression, we found a strong association between obesity and log-CRP (β ± SE: 1.43 ± 0.23; p < .001) and a moderate association between asthma and log-CRP (β ± SE: 0.48 ± 0.21; p < .028), with additive synergy between obesity and asthma. Conclusions. Both asthma and obesity are independently and synergistically associated with systemic inflammation. These findings underline the need of a multifaceted approach to address CVD risk in adolescence.