Is obesity related to the lung function of non-asthmatic children?

Table 1 Summary of studies that investigated the impact of overweight/obesity on the plethysmographic indices of lung function

No.	Ref.	No. of children, age range (yr)	Exclusion criteria for the study population	Obesity indices	Plethysmographic variables
1	Li et al[9], 2003	64, 7-18	Children with chronic cardiorespiratory problems	BMI, Trunk Body Fat, and Subtotal Body Fat (total-head). The last 2 indices were calculated as a percentage of body mass	TLC, RV, FRC
2	van de Griendt et al[8], 2012	112, 8.5-18.9	Children diagnosed as asthmatics	BM, WC	TLC, ERV
3	Davidson et al[12], 2014	327, 6-17	Children diagnosed as asthmatics	BMI	TLC, RV, FRC, ERV, VC
4	Rastogi et al[11], 2014	168, 13-18	History of smoking or chronic inflammatory conditions	BMI, WC, Waist-hip ratio	TLC, RV, FRC, RV/TLC, ERV, IC
5	Kongkiattikul et al[10], 2015	45, 8.6-17.3	Children with an underlying pulmonary disease	BMI, WC, WHR Hip circumference Body fat percentage Truncal fat percentage Fat mass index Fat free mass index	TLC, RV, FRC, RV/TLC (only results for FRC were presented)

BMI: Body mass index; TLC: Total lung capacity; RV: Residual volume; FRC: Functional residual capacity; IC: Inspiratory capacity; WC: Waist circumference; WHR: Waist-hip ratio; ERV: Expiratory reserve volume.