Reference values for exhaled nitric oxide in healthy children aged 6–18 years in China: a cross-sectional, multicenter clinical study

The reference values of eNO have certain differences among people of different countries and races. We aimed to obtain the reference value of eNO in healthy children and adolescents (6-18 years old) in China and to explore the associations between the reference values with ages, gender, heights, BMI, and regions.