Lauren King1, Esther Waugh1, Ian Stanaitis2, Alanna Weisman1, Baiju Shah1, Lorraine Lipscombe1 and Gillian Hawker1, 1University of Toronto, Toronto, ON, Canada, 2Women's College Hospital, Toronto, ON, Canada
Background/Purpose: Knee osteoarthritis (OA) and type 2 diabetes commonly co-occur due to shared risk factors. Both knee OA and type 2 diabetes negatively impact health-related quality of life (HRQoL). However, the extent to which knee OA symptoms impact the HRQoL of individuals with type 2 diabetes is unknown. Our objective was to assess the relationship between symptomatic knee OA (yes/no) and HRQoL in persons with type 2 diabetes and, if a relationship was found, to determine if it is due to depressed mood, sleep disturbance, fatigue, and/or walking limitation, which we hypothesized could be explanatory factors.
Methods: This was a cross-sectional study of individuals with type 2 diabetes ≥45 years old followed in outpatient endocrinology clinics at three academic hospitals in Toronto, Canada. Participants completed standardized online questionnaires that assessed sociodemographic factors, comorbidities to calculate the functional comorbidity index (FCI), depressed mood (PROMIS Depression 8b), sleep disturbance (PROMIS Sleep Disturbance 4a), fatigue (PROMIS Fatigue 4a), walking limitation (health assessment questionnaire walking difficulty item), HRQoL (EQ-VAS), and joint symptoms. Knee OA was defined as fulfilling NICE UK clinical criteria (activity-exacerbated knee pain, morning joint stiffness ≤ 30 minutes, no history of inflammatory rheumatic disease). We used linear regression to assess the association between knee OA (yes/no) and HRQoL, adjusting for potential confounders (age, gender, education level, BMI, and FCI). We then examined the effect of further adjustment for depressed mood, sleep disturbance, fatigue and walking limitation on the knee OA estimate of effect.
Results: Our study included 166 participants. Mean age was 66.9 (SD 9.4) years, 48.2% women, 83.1% had a post-secondary education, mean BMI 29.4 (SD 6.7) kg/m2, and 44 (26.5%) fulfilled NICE criteria for knee OA. Mean HRQoL was 62.3/100 (higher = better) (SD 20.5). Individuals with knee OA had worse HRQoL, sleep, fatigue, depressed mood, and walking limitation (p< 0.01 for all) compared to those without. After adjustment, the presence of comorbid symptomatic knee OA was associated with worse perceived HRQoL (ß -7.33, 95%CI -14.67 – 0.004). Sleep, fatigue and depressed mood were moderately correlated (Spearman r=0.42 to r=0.64). Adding any of these variables, or walking limitation, into the model fully attenuated the association between knee OA and HRQoL.
Conclusion: The presence of symptomatic knee OA adversely affects the HRQoL of persons living with type 2 diabetes. Our results suggest that this may be due to any of the downstream effects of symptomatic OA. Efforts to address quality of life in individuals with type 2 diabetes must include increased attention to diagnosis and treatment of OA.
Disclosures: L. King, None; E. Waugh, None; I. Stanaitis, None; A. Weisman, None; B. Shah, None; L. Lipscombe, None; G. Hawker, None.
