Impact of Smoking, Alcohol Use and Exercise on Underweight after Gastrectomy: A Nationwide Cohort Study of Gastric Cancer Patients in Korea

Background/Aims: ) after gastrectomy, focusing on variation across sex and age groups. Methods: We utilized a population-based cohort provided by the Korean National Health Insurance Service, which included cancer screening data. In total, 27,854 patients who underwent GC surgery between 2010 and 2016 were included. Results: Among the 27,854 patients in the study cohort, 3,064 (11.0%) were underweight. Female sex (odds ratio [OR], 1.74; 95% confidence interval [CI], 1.55 to 1.96; p<0.001) was a significant risk factor for becoming underweight postoperatively. Engaging in regular exercise (OR, 0.73; 95% CI, 0.60 to 0.89; p=0.002) and ceasing smoking (OR, 0.31; 95% CI, 0.13 to 0.78; p<0.001) emerged as substantial preventive factors against becoming underweight, particularly in female patients. Exercise (OR, 0.76; 95% CI, 0.65 to 0.89; p=0.001) proved more beneficial for patients aged <65 years. Conclusions: Smoking cessation and regular exercise are associated with a reduced risk of postoperative underweight in GC patients following gastrectomy.