Table 5.

Multiple linear regression analysis showing the association of smoking and living in PM_2.5 areas with AHRR (cg05575921) methylation in the study participants stratified by sex

Variable	Men		Women
	β	P value	β	P value
Smoking status (reference: never)
Former	− 0.01996	0.0374	− 0.04276	< 0.0001
Current	− 0.17221	< 0.0001	− 0.17706	< 0.0001
P-trend	< 0.0001		< 0.0001
Area (reference: north)
North-center	− 0.00577	0.3174	0.00092	0.9198
Center	− 0.00935	0.0820	− 0.01770	0.0361
South	− 0.01620	0.0016	− 0.02076	0.0092
P-trend	0.0013		0.0025
Exercise (no)
Yes	0.00294	0.4651	0.00001	0.9986
Age	− 0.00033	0.0939	− 0.00045	0.1278
BMI	0.00105	0.0407	− 0.00006	0.9477
Alcohol drinking (reference: no)
Former	0.03356	0.0977	− 0.00934	0.4539
Current	0.03177	0.1127	0.00115	0.9022
Secondhand smoke exposure (reference: no)
Yes	0.00361	0.5589	− 0.00060	0.9489