The association of cigarette smoking and alcohol drinking with body mass index: a cross-sectional, population-based study among Chinese adult male twins

Table 2 Adjusted effects (with 95 % CI and coefficient[β]) of cigarette smoking and alcohol drinking on BMI (N = 12242)

Lifestyle factors	All twins (Model 1)		Within MZ twin pairs (Model 2)		Within DZ twin pairs (Model 3)
Lifestyle factors	β (95 % CI)	P	β (95 % CI)	P	β (95 % CI)	P
Cigarette pack-years^a	−0.008 (−0.013, −0.003)	0.001	−0.007 (−0.014, −.0004)	0.038	−0.019 (−0.032, −0.005)	0.007
Cigarette smoking status (reference group: nonsmoker)^a
Former smoker	0.475 (0.196, 0.754)	0.001	0.376 (0.049, 0.704)	0.024	0.612 (−0.077, 1.300)	0.082
Light smoker	−0.008 (−0.178, 0.161)	0.926	0.122 (−0.092, 0.336)	0.264	−0.194 (−0.620, 0.233)	0.373
Moderate to heavy smoker	−0.115 (−0.223, −0.007)	0.037	−0.163 (−0.310, −0.017)	0.029	−0.357 (−0.642, −0.071)	0.014
Alcohol drinking status (reference group: nondrinker)^b
Former drinker	0.075 (−0.286, 0.435)	0.686	0.402 (0.003, 0.801)	0.048	−0.960 (−1.986, 0.067)	0.067
Current drinker	0.317 (0.203, 0.430)	< 0.001	0.096 (−0.066, 0.258)	0.245	0.307 (−0.008, 0.622)	0.056

Abbreviations: MZ monozygotic, DZ dizygotic, BMI body mass index, CI confidence interval
^aAdjusted for age, region, zygosity, marital status, education level, alcohol drinking status and regular physical activity in three models
^bAdjusted for age, region, zygosity, marital status, education level, cigarette smoking status and regular physical activity in three models

ISSN: 1471-2458