Associations of dual use of tobacco cigarettes and e-cigarettes, sleep duration, physical activity and depressive symptoms among middle-aged and older Korean adults.

In multinomial logistic regression, dual users of tobacco cigarettes and e-cigarettes were more likely to have sleep duration of less than 7 h per day and to report both mild and moderate-to-severe depressive symptoms than non-smokers. Single use of either cigarettes or e-cigarettes increased the risk of short sleep duration and moderate-to-severe depressive symptoms.