Effects of Shift Work on Knee Pain and Knee Osteoarthritis Among Retired Chinese Workers

摘要

Objectives: To evaluate the association between shift work with the risk of knee pain and knee osteoarthritis (KOA), we studied 13,906 retired workers from the Dongfeng-Tongji cohort. Methods: Physical examinations and face-to-face interviews were performed. Knee pain was diagnosed by self-reported pain or stiffness. Clinical KOA was diagnosed from knee pain complains and clinical X-ray radiographs. Occupation history including work content and shift work experience in each job was collected from questionnaires. Results: The prevalence of knee pain and clinical KOA was 39.0% and 6.7%, respectively. After adjusting for potential confounders, shift work was independently associated with elevated risk of knee pain (OR 1.24, 95% CI 1.15-1.33) and clinical KOA (1.15, 1.01-1.32). Such associations remained stable in stratified analyses by age, gender, BMI, work postures, or chronic diseases. Additionally, in comparison with daytime workers, the risks increased with prolonged duration of shift work, the ORs (95% CI) of knee pain for participants with 1-9 years, 10-19 years, and>20 years of shift work were 1.20 (1.08-1.33), 1.26 (1.14-1.40), and 1.26 (1.12-1.40), and ORs (95% CI) of clinical KOA were 1.06 (0.87-1.30), 1.15 (0.94-1.40), and 1.26 (1.02-1.56). However, the effects of shift work on knee gradually reduced with the extended duration of leaving shift work. Conclusions: Shift work might be independent risk factor for knee pain and clinical KOA among the retired workers.