Diet-induced weight loss in obese children with asthma: a randomized controlled trial
Article first published online: 21 JUN 2013
© 2013 John Wiley & Sons Ltd
Clinical & Experimental Allergy
Volume 43, Issue 7, pages 775–784, July 2013
How to Cite
Clinical & Experimental Allergy, 2013; (43) 775–784., , , , .
- Issue published online: 21 JUN 2013
- Article first published online: 21 JUN 2013
- Accepted manuscript online: 26 MAR 2013 01:25PM EST
- Manuscript Accepted: 20 FEB 2013
- Manuscript Revised: 18 FEB 2013
- Manuscript Received: 10 DEC 2012
- Hunter Medical Research Institute Gastronomic Society Donor Grant
- Australian National Health and Medical Research Council Career Development Fellowship
- University of Newcastle Priority Research Centre
- body composition;
- body mass index;
- respiratory function tests;
- weight loss
Obesity is highly prevalent in asthmatic children and associated with worse clinical outcomes. Energy restriction to induce weight loss in asthmatic children has not been investigated in a randomized controlled trial (RCT).
To assess if (1) weight loss can be achieved in obese asthmatic children using a dietary intervention; and (2) changes in asthma outcomes occur following diet-induced weight loss.
In a 10-week pilot RCT, obese asthmatic children, aged 8–17 years, were randomized to a wait-list control (WLC) (n = 15) or dietary-intervention group (DIG) (n = 13). Lung function, Asthma Control Questionnaire (ACQ) score, and sputum and systemic inflammation were assessed at baseline and post-intervention. (Australian New Zealand Clinical Trials Registry: ACTRN12610000955011).
Body mass index (BMI) z-score reduced significantly in the DIG vs. the WLC (−0.2 [−0.4, −0.1] vs. 0.0 [−0.1, 0.0], P = 0.014). Expiratory reserve volume (ERV) increased significantly within the DIG, but not compared to the WLC (0.7 [0.0, 1.0] L vs. 0.3 [0.0, 0.8] L, P = 0.355). ACQ improved significantly in the DIG, compared to the WLC (−0.4 [−0.7, 0.0] vs. 0.1 [0.0, 0.6], P = 0.004). Airway and systemic inflammation did not change within the DIG. In comparison, C-Reactive Protein (CRP) increased significantly in the WLC (−0.4 [−0.5, 0.4] vs. 0.7 [−0.1, 1.9], P = 0.037). Change (∆) in BMI z-score correlated with ∆CRP (r = 0.47, P = 0.012) and ∆exhaled nitric oxide (eNO) (r = 0.46, P = 0.034), and ∆ACQ was associated with ∆CRP (r = 0.43, P = 0.029).
Conclusion and Clinical Relevance
Dietary intervention can induce acute weight loss in obese asthmatic children with subsequent improvements in static lung function and asthma control. Systemic and airway inflammation did not change following weight loss. However, changes in BMI z-score were associated with changes in airway and systemic inflammation and this requires further investigation in a larger RCT. This is the first weight loss RCT conducted in obese asthmatic children. Diet-induced weight loss can achieve significant improvements in clinical outcomes for obese children with asthma.