The Impact of Diabetes on Osteoarthritis Prevalence and Pain

Abstract

A growing body of evidence shows that there is an association between osteoarthritis (OA) and Type 2 diabetes mellitus (DM). However, the impact of DM on OA prevalence, specific OA locations, and pain remain poorly understood. Therefore, the primary purpose of this work was to examine the association of DM with OA in terms of prevalence and pain using large data sets. Particularly, three specific aims were studied in this dissertation. First, we examined the prevalence and risk factors for generalized OA (involving 3 or more joints) compared localized OA (involving only one or two joints). Second, we examined the association between type 2 DM and pain severity in people with localized OA. Finally, we examined the association between DM and knee pain locations, including localized, regional and diffused knee pain in people with knee OA. Chapter 2 describes a preliminary work for this dissertation examining the association of DM with knee pain severity and knee pain distribution (unilateral or bilateral versus no pain) in people with knee OA. This work included a cross-sectional analysis of the baseline visit of individuals who were enrolled in the Osteoarthritis Initiative. Data for participants with knee OA were used for this analysis (n=1319). Pain severity was measured using a numeric rating scale from 0 to 10 over the past 7 and 30 days for each knee. We found that DM was significantly associated with increased knee pain severity. Moreover, we observed a significant association between DM and unilateral and bilateral knee pain. These results indicated the potential effect of DM on short-term and long-term knee pain severity as well as joint distribution. Building upon the preliminary findings from the preliminary study in chapter 2, we examined the association between DM and OA with a focus on comparing people with generalized and localized OA. As described in chapter 3, we examined the prevalence of type 2 DM among people with generalized OA compared to localized OA along with the associated risk factors including demographic risk factors and chronic diseases (i.e. Type 2 DM, hypertension, dyslipidemia, neuropathy, and body mass index). A retrospective review of data was performed using the Healthcare Enterprise Repository for Ontological Narration (HERON), and patients with diagnostic codes for OA were selected. Data from 3855 individuals included patients with generalized OA (n=1265) and localized OA (n=2590). The prevalence of type 2 DM was significantly greater among patients with generalized OA compared to localized OA. Significant associations were found between generalized OA and type 2 DM, hypertension, and dyslipidemia. The findings from this chapter highlighted that chronic diseases including type 2 DM, hypertension and dyslipidemia might affect any joints or multiple parts due to their systemic inflammatory impact on joints and vascular systems innervating joints resulting in generalized OA. Investigating the association between type 2 DM and OA in further details, we analyzed the association of type 2 DM with pain severity in people with localized OA to understand the association whether limited to knee joint as described in chapter 2 or at any other localized joint. Chapter 4 examined the association between Type 2 Diabetes and pain severity in people with localized OA, and explored the association between glycemic control measured by A1c level and pain severity in people with localized OA and type 2 DM. A retrospective design using HERON database was used, and data from 819 patients were obtained and grouped into localized OA only (n=671) and localized OA+type2 DM (n=148) based on diagnoses codes. An index date was set as the first diagnosis date of localized OA and linked to pain severity, measured by numeric rating scale from 0 to 10. Hemoglobin A1c values were