Progression of knee osteoarthritis among female occupational breath-hold divers (Haenyeo): A Retrospective Cohort Study

BACKGROUND: Knee osteoarthritis (OA) is a prevalent degenerative disease in older adults, particularly postmenopausal women. Aquatic activity is known to relieve symptoms and may protect joint health. Haenyeo, traditional female occupational breath-hold divers of Jeju Island, South Korea, perform lifelong breath-hold diving with intense aquatic labour, offering a unique model to study long-term aquatic exposure and knee OA outcomes. AIMS: To evaluate the impact of lifelong aquatic activity on OA progression and postoperative outcomes in Haenyeo compared with non-diving women. METHODS: We performed a retrospective cohort study of 16 763 women aged ≥50 years with clinically confirmed primary knee OA treated at a tertiary hospital in South Korea between 2004 and 2023. Of these, 2390 were identified as Haenyeo from occupational history. Patients were followed until total knee arthroplasty (TKA), death, or August 2024. Outcomes included age at diagnosis, risk of TKA, 30-day readmission, complications and length of hospital stay. Cox proportional hazards models adjusted for disease severity and comorbidities. RESULTS: Haenyeo were diagnosed later than non-Haenyeo (mean difference 2.8 years; 95% confidence interval [CI], 2.4-3.2) and showed a reduced risk of TKA (adjusted hazard ratio [HR], 0.86; 95% CI, 0.77-0.95). Among 3989 TKA patients, Haenyeo had lower 30-day readmission (adjusted HR, 0.70; 95% CI, 0.58-0.85), with no significant differences in complications or length of hospital stay. CONCLUSIONS: Haenyeo exhibited delayed diagnosis, slower OA progression and favourable short-term postoperative outcomes. Sustained aquatic activity may provide protective effects on joint health and recovery in older women.