Mediating pathways from central obesity to childhood asthma: a population-based longitudinal study

Abstract

The mediating pathways linking obesity and asthma are largely unknown. We aimed to investigate the mediating pathways and to search for the most prominent pathological mechanism between central obesity and childhood asthma.In the Taiwan Children Health Study, we collected data on an open cohort of children aged 9-13 years. Children's respiratory outcomes, atopic conditions, obesity measures and pulmonary function were surveyed annually between 2010 and 2012. Exhaled nitric oxide fraction concentrations were recorded in 2012. Generalised estimating equations and general linear models were used to examine the associations between central obesity, possible mediators and asthma. Structural equation models were applied to investigate the pathways that mediate the link between central obesity and asthma.Central obesity (waist-to-hip ratio) most accurately predicted childhood asthma. In the active asthma model, the percentage of mediation was 28.6% for pulmonary function, 18.1% for atopy and 5.7% for airway inflammation. The percentage of mediation for pulmonary function was 40.2% in the lifetime wheeze model. Pulmonary function was responsible for the greatest percentage of mediation among the three mediators in both models.Decline in pulmonary function is the most important pathway in central obesity related asthma. Pulmonary function screening should be applied to obese children for asthma risk prediction.

The effect of obesity, weight gain, and weight loss on asthma inception and control

“…On the other hand, obese children have been shown to have a low FEV 1 /FVC ratio 3,31 consistent with an obstructive deficit that could partly account for their increased asthma morbidity. For example, a study of over 2,700 children Taiwanese children showed that low FEV 1 /FVC was the most significant “mediator” between central obesity and active childhood asthma 32 . Moreover, normal-weight children with asthma who become obese in early adulthood have further worsening of FEV 1 /FVC (up to ~3% per each 10-kg/m 2 change in BMI), without significant changes in FVC 33 .…”

Expression Levels of Predominant Adipokines and Activations of STAT3, STAT6 in an Experimental Mice Model of Obese Asthma

“…The interactions between obesity and the accompanying metabolic syndrome and diseases such as asthma have proven complex and often counterintuitive in human studies. 20,21 Hence, there is a growing need for relevant experimental approaches to understand the interactions between obesity and the lung. It is well known that obesity is a low-grade chronic pro-inflammatory condition and obesitymediated changes in plasma adipokines have been associated with increased systemic and airway inflammation.…”

The Challenge of Obesity and Asthma in Children and Adolescents

“…Moreover, conversion to sexand age-adjusted percentiles or z-scores may not suffice. For obese children and adolescents, BMI percentiles or z-scores correlate poorly with other measures of adiposity 3 when using markers of central obesity such as waist circumference or waist-to-hip ratio 95 , neck circumference 96,97 , skinfold-derived calculations of body fat 48 , ultrasound 98 , or dual-energy X-ray absorptiometry (DXA) 98,99 . Improved ways to evaluate obesity, as well as increased recognition of different adiposity distribution patterns, may improve our understanding of the impact of obesity on asthma.…”