Table 2

Associations between BMI status at 8 and 16 years and impulse oscillometry 16 years (n=1016 girls at 8 years and 1258 girls at 16 years, n=999 boys at 8 years and 1191 boys at 16 years)

	R_5–20 (Pa·L⁻¹·s)						AX^0.5 (Pa·L⁻¹)^0.5
	Girls			Boys			Girls			Boys
	β*	95% CI	P value	β*	95% CI	P value	β*	95% CI	P value	β*	95% CI	P value
BMI status 8 years
Thinness	8.6	−10.0 to 27.2	0.36	−8.8	−25.2 to 7.5	0.29	0.8	−1.0 to 2.7	0.36	−1.0	−2.6 to 0.6	0.21
Normal weight	Referent			Referent			Referent			Referent
Overweight	10.9	2.0 to 19.7	0.02	6.8	−0.57 to 14.1	0.07	1.1	0.3 to 2.0	0.009	0.4	−0.3 to 1.2	0.23
Obesity	11.6	−8.2 to 31.3	0.25	31.7	16.7 to 46.7	<0.001	−0.4	−2.4 to 1.5	0.65	2.3	0.8 to 3.8	0.003
BMI status 16 years
Thinness	−15.9	−25.8 to −6.0	0.002	−12.9	−21.9 to −3.9	0.005	−0.4	−1.4 to 0.6	0.42	−0.3	−1.2 to 0.7	0.58
Normal weight	Referent			Referent			Referent			Referent
Overweight	32.7	24.5 to 40.9	<0.001	22.3	16.1 to 28.5	<0.001	3.1	2.3 to 3.9	<0.001	1.6	0.9 to 2.2	<0.001
Obesity	56.8	38.3 to 75.4	<0.001	47.8	34.9 to 60.7	<0.001	3.1	1.3 to 4.9	0.001	3.5	2.2 to 4.8	<0.001

*Represent median difference in outcome compared with the reference group, calculated by linear regression on the median adjusted for age and height.
AX^0.5, area under the reactance curve; BMI, body mass index; R, frequency dependence of resistance.