Severity of diabetes mellitus and risk of total hip or knee replacement: A population based case-control study

Background: It is generally thought that people with diabetes mellitus (DM) are more likely to suffer from OA due to an increased Body Mass Index (BMI), resulting in the mechanical destruction of cartilage. However, previous studies have shown that DM could also be an independent risk factor for OA, suggesting other causative factors are involved (Nieves-Plaza M, 2013; Schett G, 2013). Objectives: To evaluate the risk of hip or knee replacement, as a proxy for severe osteoarthritis (OA), in patients with diabetes mellitus (DM) compared to non-diabetic patients. We additionally evaluated the risk of total joint replacement (TJR) with various proxies for increased DM severity. Methods: We performed a population based case-control study using the Clinical Practice Research Datalink (CPRD). Cases (n=94,609) were defined as patients >18 years who had undergone TJR between 2000 and 2012. Controls were matched by age, gender and general practice. Conditional logistic regression was used to estimate the risk of total knee (TKR) and total hip replacement (THR) surgery associated with use of antidiabetic drugs (ADs). We additionally stratified current AD users by proxies for DM severity. Results: Current AD use was significantly associated with a lower risk of TKR (OR=0.86 (95% CI=0.78-0.94)) and THR (OR=0.90 (95% CI=0.82-0.99)) compared to patients not using ADs. Moreover, risk of TKR and THR was decreased with increasing HbA1c. Conclusions: In contrast to previous research, this study does not support the hypothesis that diabetic patients are more likely to suffer from severe OA as compared to non-diabetic patients. This is possibly due to methodological and medical dissimilarities between studies.