Smoking Cessation, Weight Change, Diabetes, and Hypertension in Korean Adults

Introduction: This study investigates the association of smoking cessation and postcessation weight gain with the development of type 2 diabetes mellitus and hypertension. Methods: A total of 96,524 individuals without diabetes mellitus and hypertension aged ≥20 years between 2006 and 2008 were included, with follow-up until December 31, 2015. Smoking status and weight changes were monitored for 2 years. Hazard ratios and 95% CIs were calculated for the respective risks of the 2 conditions. Analyses were completed in 2020. Results: Compared with current smokers, the adjusted hazard ratios for the risk of type 2 diabetes and hypertension were 0.90 (95% CI=0.85, 0.96) and 1.00 (95% CI=0.95, 1.05) in recent quitters, 0.89 (95% CI=0.84, 0.95) and 0.92 (95% CI=0.88, 0.97) in long-term quitters, and 0.82 (95% CI=0.78, 0.86) and 0.92 (95% CI=0.89, 0.95) in never smokers. Compared with current smokers, the adjusted hazard ratios for the risk of type 2 diabetes and hypertension were 0.86 (95% CI=0.80, 0.93) and 0.98 (95% CI=0.92, 1.04) in recent quitters with no weight gain, 0.94 (95% CI=0.87, 1.03) and 1.00 (95% CI=0.94, 1.07) in those with 0.1-5 kg weight gain, 0.93 (95% CI=0.73, 1.19) and 1.14 (95% CI=0.96, 1.36) in those with 5.1-10 kg weight gain, and 1.49 (95% CI=0.84, 2.62) and 1.10 (95% CI=0.68, 1.77) in those with a weight gain of >10 kg. Conclusions: Smoking cessation with no subsequent weight gain is associated with a reduced risk of developing type 2 diabetes. However, weight gain after smoking cessation attenuates the reduced risk of type 2 diabetes. The association between recent quitting and incident hypertension was nonsignificant, whereas long-term quitters had reduced risk of developing hypertension and type 2 diabetes.restrictio