Association Between Smoking Behavior and Insulin Resistance Using Triglyceride-Glucose Index Among South Korean Adults

Context: Insulin resistance is a determinant of diabetes. With the increasing popularity of electronic smoking, the number of dual smokers (smoking both cigarettes and electronic cigarettes [e-cigarettes]) is increasing. However, few studies have assessed the association between insulin resistance and smoking behavior, including dual smoking. Objective: This work aims to investigate the association between smoking behaviors and insulin resistance. Methods: This prospective, cross-sectional study took place among the general community. A total of 11653 participants (4721 male and 6932 female) aged 19 years or older from the 2016 to 2018 Korea National Health and Nutrition Examination Survey were divided based on their smoking behaviors: dual smokers (both cigarettes and e-cigarettes), single smokers (cigarette smokers), previous smokers, and nonsmokers. Insulin resistance was determined based on the triglyceride-glucose index. Multiple logistic regression analysis was performed to investigate the association between smoking behavior and insulin resistance. Results: Among the participants, 205 males (3.9%) and 40 females (0.5%) were dual smokers, and 1581 males (29.9%) and 350 females (4.5%) were single smokers. Male and female smokers (dual and single) both had higher odds of being in a group with higher insulin resistance than nonsmokers (male, dual: OR=2.19; 95% CI, 1.39-3.44; single: OR=1.78; 95% CI, 1.43-2.22; female, dual: OR=2.32; 95% CI, 1.01-5.34; single: OR=1.76; 95% CI, 1.28-2.42). Conclusion: This study suggests that single and dual smoking both may increase the risk of insulin resistance in the general population. Education on the adverse effects of smoking behaviors may be an important strategy to improve the health of the population.