TABLE 4.

Estimated differences in forced expiratory volume in 1 s (FEV₁) with 95% confidence intervals (CIs) stratified by both changes in body mass index (BMI) and waist circumference (WC) at a fixed level of the other variable

	Comparison between WC values cm	BMI kg·m−2 (fixed level)	FEV1 z-score (estimated difference)	95% CI
Men	90 versus 70	20	−0.44	−0.78 to −0.10
	105 versus 85	25	−0.56	−0.70 to −0.42
	115 versus 95	30	−0.83	−0.96 to −0.69
Women	85 versus 65	20	−0.21	−0.35 to −0.06
	95 versus 75	25	−0.36	−0.45 to −0.28
	105 versus 85	30	−0.34	−0.48 to −0.20
	Comparison between BMI values kg·m−2	WC cm (fixed level)	FEV1 z-score (estimated difference)	95% CI
Men	28 versus 22	90	0.48	0.33–0.63
	30 versus 24	100	0.39	0.26–0.52
	32 versus 26	105	0.31	0.20–0.42
Women	26 versus 20	80	0.32	0.23–0.42
	28 versus 22	90	0.27	0.18–0.36
	30 versus 24	95	0.21	0.11–0.31