Diabetes, poor glycemic control, and a longer duration of diabetes were found to be associated with increased risk for symptomatic knee osteoarthritis, according to the results of a study published in Arthritis Care & Research.
Investigators used data from the China Health and Retirement Longitudinal Study to evaluate the independent associations of symptomatic knee OA with diabetes status, glycemic control as measured by glycated hemoglobin (HbA1c), diabetes duration, and biomarkers of hyperglycemia.
Diabetes was defined as an individual having an HbA1c ≥6.5% (48 mmol/mol), a self-reported physician diagnosis, or reported use of glucose-lowering drugs. The investigators dichotomized HbA1c at 7% (53 mmol/mol) in patients with diabetes.
A total of 10,730 participants without knee osteoarthritis (mean age, 58.2 years; 52.1% women) were included, of whom 1003 met the diagnostic criteria for diabetes. The median follow-up for incident events was 5 years (mean, 4.8 years).
Among participants without knee osteoarthritis at baseline, 55 symptomatic knee osteoarthritis cases occurred in patients with diabetes with an HbA1c <7% (53 mmol/mol), and 63 symptomatic knee osteoarthritis cases occurred in those with an HbA1c ≥7% (53 mmol/mol). These rates corresponded with incidence rates of 21.9 (95% CI, 16.9-28.6) and 29.4 (95% CI, 22.9-37.6) per 1000 person-years, respectively. Patients with diabetes regardless of HbA1c value were more likely to develop symptomatic knee osteoarthritis (hazard ratio [HR], 1.38; 95% CI, 1.14-1.67), according to unmodulated Cox models.
The presence of diabetes regardless of HbA1c level vs no diabetes remained a significant predictor of symptomatic knee osteoarthritis after the investigators controlled for other putative risk factors, including age and body mass index (HR, 1.32; 95% CI, 1.09-1.61; P =.005). No differences were observed following the exclusion of participants with hand pain or hip pain at baseline (HR, 1.29; 95% CI, 1.02-1.78).
Duration of diabetes was significantly greater in patients who developed symptomatic knee osteoarthritis vs those without symptomatic knee osteoarthritis during follow-up (mean ± SD, 10.4 ± 8.8 vs 8.2 ± 7.2 years, respectively). A greater risk of incident symptomatic knee osteoarthritis was significantly associated with higher HbA1c (>7.7% [61 mmol/mol]) and with higher fasting blood glucose (>186 mg/dL).
In participants in the first tertile of baseline age (<53 years), the risk of symptomatic knee osteoarthritis was approximately twice as high for those with a duration of diabetes longer than >5 years vs those with a duration of diabetes shorter than 5 years, although this finding was not significant (adjusted HR, 2.02; 95% CI, 0.83-4.96). In the medium tertile of baseline age (53-62 years), duration of diabetes shorter than 5 years vs longer than 5 years was associated with an increased risk of symptomatic knee osteoarthritis (adjusted HR, 1.27; 95% CI, 0.63-2.56).
Study limitations include the absence of data regarding glycated albumin, 1,5-anhydroglucitol, or fructosamine, as well as a population comprising only Chinese adults with diabetes. Also, osteoarthritis was confirmed according to self-reported data, and the definition of diabetes included receiving diabetes medicine.
“Glycemic control is related to the risk of symptomatic knee OA in older adults, which may provide a simple and direct way to identify older adults at high risk for symptomatic knee OA,” concluded the study authors.
Zheng J, Huang X, Huang J, et al. Associations of diabetes status and hyperglycemia with symptomatic knee osteoarthritis. Arthritis Care Res (Hoboken). Published online February 28, 2022. doi:10.1002/acr.24872