Table 3. Association between metabolic syndrome and electronic cigarette exposure.

	Never user (n = 13,459)	Ever user (n = 954)	Current user (n = 325)	P trend
	Reference	OR (95% CI)	OR (95% CI)
Prevalence of MetS, % (SE)	23.6 (0.4)	26.8 (1.6)	25.9 (0.2)	0.08
Model 1	1	1.51 (1.26–1.82)	1.53 (1.16–2.01)	<0.001
Model 2	1	1.28 (1.05–1.54)	1.27 (0.96–1.69)	0.01
Model 3	1	1.26 (1.04–1.52)	1.28 (0.96–1.70)	0.01
Model 4	1	1.25 (1.03–1.51)	1.27 (0.96–1.69)	0.01

a) Model 1 was adjusted for age and sex; Model 2 was additionally adjusted for conventional cigarette exposure; Model 3 was additionally adjusted for alcohol consumption; and Model 4 was additionally adjusted for physical activity, household income, and education level.

b) The P-value for trend was measured using a logistic regression analysis considering electronic cigarette exposure as a continuous variable.

OR: odds ratio, CI: confidence interval.