Why Do Young Adults Sleep Less? A Comparative Analysis of Sleep Duration and Smoking Status among University Students of Karachi, Pakistan

Background: Smoking tobacco, either in the form of traditional combustion cigarettes (TCC) or electronic cigarettes (EC) are recognized for their long-term adverse health outcomes. In addition, tobacco smoking has been linked to sleep quality, which in turn undermines overall health and well-being. Objective: To examine the association between sleep duration and smoking status, distinguishing between exclusive TCC users, exclusive EC users, dual users of both products, and non-smokers among university students in Karachi, Pakistan. Method: This cross-sectional study included 450 university students of Karachi, Pakistan, aged 18-25 years using non-probability multistage sampling technique. Participants were categorized as exclusive use of TCC, exclusive EC use, dual use or non-smoking. Structured questionnaire was used, focusing on duration and perceived changes. Data was analyzed using SPSS version 25. Results: Out of 450 participants, 351(78%) reported use of smoking products. Multivariate logistic regression model revealed that dual users had significantly higher odds of less than six hours (AOR=9.60; 95% CI: 3.99–23.11, p<0.001). Traditional cigarette use was also strongly associated with short sleep duration (AOR=3.09; 95% CI: 1.31–7.28, p=0.010), whereas the relationship for EC users approached statistical significance (AOR=2.28; 95%; CI: 0.99–5.27, p=0.054). Conclusion: Dual tobacco users are more likely to experience reduced sleep duration than non-smokers, highlighting an important public health concern. Longitudinal studies are essential in future to establish causality and to design interventions that address the behavioral and psychological factors of smoking behavior.