Background: Childhood obesity is an important public health problem worldwide, while the effect of obesity on exhaled nitric oxide in children remains unclear. This study aimed to investigate the prevalence of obesity and overweight in Asian children in Taiwan, with emphasis on the influence of increasing weight status on fraction of exhaled nitric oxide (FeNO). Methods: Asian children aged 4 – 18 years (N = 5393) in the Prediction of Allergies in Taiwanese Children (PATCH) study were evaluated using questionnaires and anthropometric measurements. Single-breath online FeNO was measured in a sampling cohort of 1717 subjects that is representative of the source population. Results: With the use of the International Obesity Task Force (IOTF) criteria, the prevalence of obesity and overweight in children was 8.3% and 20.8%, respectively. The prevalence of obesity (11.5% of boys and 5.1% of girls) and overweight (23.0% of boys and 18.6% of girls) was significantly higher among boys than girls (both P < 0.001). After adjusting for confounders, obese children had significantly lower FeNO levels than normal-weight children, with mean difference of 4.7 ppb (SE, 2.1 ppb; P = 0.026). Overweight children also had lower FeNO levels than normal-weight children, though the difference did not reach statistical significance after adjusting for confounders. Similar results were obtained when children with asthma were excluded from the analysis. Conclusion: Our study highlights a high prevalence of childhood obesity and overweight in Taiwan, with 3 out of 10 preschool and school children are either obese or overweight. Our results demonstrate that obesity is associated with a decrease in FeNO in children.
