Association between Knee Osteoarthritis and Cardiovascular Disease in Type 2 Diabetes Mellitus: Impact of Exercise

Abstract Knee osteoarthritis (OA), type 2 diabetes mellitus (T2DM), and cardiovascular disease (CVD) are major chronic conditions that frequently co-occur, posing substantial health burdens. This study aimed to investigate the association between knee OA and CVD outcomes in patients with T2DM, as well as the impact of exercise behavior on these associations. Utilizing data from the National Health Insurance Service (NHIS) in South Korea, we examined a cohort of 1,091,898 individuals diagnosed with T2DM between 2009 and 2012. The incidence rates of CVD, myocardial infarction (MI), stroke, heart failure (HF), and cardiovascular mortality were significantly higher in the knee OA group compared to those without knee OA (CVD: 23.25 vs. 18.23 per 1000 person-years; MI: 4.38 vs. 3.86; stroke: 11.70 vs. 8.97; HF: 10.62 vs. 8.19; CV mortality: 2.26 vs. 1.91). After adjusting for confounding factors, knee OA was associated with an increased risk of CVD (HR 1.13, 95% CI 1.11–1.16), MI (HR 1.07, 95% CI 1.02–1.13), stroke (HR 1.14, 95% CI 1.10–1.18), and HF (HR 1.13, 95% CI 1.09–1.17). Regular and intermittent exercise significantly reduced the risk of CVD, MI, stroke, HF, and cardiovascular mortality in T2DM patients with knee OA (e.g., regular exercise: HR 0.63, 95% CI 0.52–0.76; intermittent exercise: HR 0.69, 95% CI 0.61–0.78 for CV mortality). The association between knee OA and increased CVD risk was more pronounced in non-insulin users (HR 1.13, 95% CI 1.10-1.16) and those with a shorter duration of diabetes (HR 1.10, 95% CI 1.07-1.13). These results underscore the importance of promoting physical activity to mitigate cardiovascular risks in T2DM patients with knee OA. Incorporating exercise into care strategies is crucial for improving cardiovascular health in this population.