Association of Diabetes Mellitus Status and Hyperglycemia With Symptomatic Knee Osteoarthritis

Emerging evidence indicates that hyperglycemia has an adverse impact on the knee joint which, in turn, may increase the risk of knee osteoarthritis (OA), but evidence from the real-life settings of large-scale cohort studies remains unclear. We sought to evaluate the association of glycemic control and the risk of symptomatic knee OA in a community-based cohort of older adults.

We conducted a prospective analysis of 10,730 participants without knee OA. Comprehensive blood biomarker data were obtained. Diabetes mellitus (DM) was defined mainly using a glycosylated hemoglobin (HbA_1c ) level of ≥6.5%; poor glycemic control in individuals with DM was defined as an HbA_1c level of ≥7%. We fit Cox regression models, stratified according to DM status. We evaluated the hazards associated with HbA_1c and fasting blood glucose levels using a spline model.

During a median follow-up of 5 years, knee OA developed in 1,089 participants (108 with DM and 971 without). Knee OA was related to DM (hazard ratio [HR] 1.29 [95% confidence interval (95% CI) 1.02-1.78]), bad glycemic regulation in DM patients (HR 1.41 [95% CI 1.05-2.09]), and long-term DM (≥5 versus <5 years; HR 1.49 [95% CI 1.02-2.17]). High levels of HbA_1c (>7.7% and 61 mmoles/mole) and fasting blood glucose (>186 mg/dl) were significantly associated with higher risk of incident knee OA.

DM, bad glycemic management, and long-term DM are potential risk factors of symptomatic knee OA independent of age and body mass index. Targeting blood glucose, in addition to bodyweight, may be an important avenue for prevention of knee OA.