Association Between Knee Osteoarthritis and the Risk of Cardiovascular Disease and the Synergistic Adverse Effects of Lack of Exercise

Abstract

Abstract Objectives: We aimed to determine whether knee OA is associated with CVD risk and to evaluate whether the association differs by exercise behavior. Methods: We used Korea National Health Insurance Service (KNHIS) database and included 201,466 participants (7,572 subjects diagnosed with knee OA) who underwent health screening between 2009 and 2015. Those who had been diagnosed with knee OA or CVD before the index year were excluded. Cox proportional hazard models were used after adjusting for sociodemographic and CVD risk factors to evaluate the association between knee OA and CVD risk. Stratification analysis was further performed to determine the effect of exercise behavior on this relationship. Results: During a median follow-up of 7.06 ± 2.24 years, 8,743 CVD (2,510 MI and 6,553 stroke) cases developed. Individuals with knee OA had increased risks of CVD (hazard ratio (HR) 1.26, 95% confidence interval (CI) 1.15–1.38), myocardial infarction (MI) (HR 1.20, 95% CI 1.00–1.44), and stroke (HR 1.29, 95% CI 1.16–1.43) compared with those without knee OA. Those with knee OA who did not exercise had an increased risk of CVD (HR 1.25, 95% CI 1.11-1.40), whereas no significant increased CVD risk was observed in those with knee OA who exercised at least once a week (HR 1.11, 95% CI 0.96-1.28). Conclusion: Knee OA was independently associated with an increased risk of CVD. Lack of exercise might have a synergistic adverse effect on the association between knee OA and CVD.