Cross-sectional association between long working hours and endoscopic gastritis: the Kangbuk Samsung Health Study

• Published in: BMJ open 2021-09, Vol.11 (9), p.e050037
• Main Authors: Mun, Eunchan, Lee, Yesung, Lee, Woncheol, Park, Soyoung
• Format: Article
• Language: English
• Subjects: Abdomen; Alcohol use; Anti-inflammatory agents; Body mass index; Cancer; Cardiovascular disease; Cholesterol; Classification; Diabetes; Employees; Endoscopy; Exercise; gastroduodenal disease; High density lipoprotein; Laboratories; Lifestyles; Medical screening; occupational & industrial medicine; Occupational and Environmental Medicine; Physical fitness; public health; Questionnaires; Womens health; Working hours
• ISSN: 2044-6055; 2044-6055
• DOI: 10.1136/bmjopen-2021-050037

ObjectivesThis study aimed to determine the cross-sectional association between long working hours and gastritis diagnosed by endoscopy.DesignCross-sectional study.SettingLarge university hospitals in Seoul and Suwon, South Korea.ParticipantsWorkers in formal employment who underwent a comprehensive health examination at the Kangbuk Samsung Hospital Total Healthcare Centre clinics in Seoul and Suwon, South Korea, between January 2011 and December 2018. Of the 386 488 participants, 168 391 full-time day workers met the inclusion criteria and were included in the analysis.Primary outcome measureEndoscopic gastritis.ResultsThe participants were predominantly college graduates or above (88.9%), male (71.2%) and in their 30s (51.1%), and the median age was 36 (IQR 31–42). Approximately 93.2% of participants had positive endoscopic gastritis, and there was a significant association between working hours and positive findings of endoscopic gastritis. The multivariate fully adjusted prevalence ratio (PR) of endoscopic gastritis for participants working >55 hours per week compared with 35–40 hours per week was 1.011 (95% CI 1.007 to 1.015). Furthermore, endoscopic findings were classified into nine subtypes of gastritis, including superficial gastritis, erosive gastritis, atrophic gastritis, intestinal metaplasia and haemorrhagic gastritis increased with longer working hours (p for trends 55 hours per week compared with 35–40 hours per week were 1.019 (95% CI 1.012 to 1.026), 1.025 (95% CI 1.011 to 1.040), 1.017 (95% CI 1.008 to 1.027), 1.066 (95% CI 1.028 to 1.105) and 1.177 (95% CI 1.007 to 1.375), respectively.ConclusionsWorking over 55 hours per week was cross-sectionally associated with positive findings of endoscopic gastritis. The study findings indicated potentially increased risks of superficial gastritis, erosive gastritis, atrophic gastritis, intestinal metaplasia and haemorrhagic gastritis among workers with long working hours (>55 hours per week), supporting the need for further exploration via longitudinal studies.