Serum cholesterol and osteoarthritis. The baseline examination of the Ulm Osteoarthritis Study

To assess the association between serum cholesterol and osteoarthritis (OA).

OA patterns were studied in 809 patients with knee or hip joint replacement due to OA in 4 hospitals in southwest Germany. Participants had a standardized interview and examination. Radiographs of the contralateral joint as well as both hands and a blood sample were obtained. Serum cholesterol levels were divided into tertiles and hypercholesterolemia was defined as > or = 6.2 mmol/l or use of antihyperlipidemic drugs. According to the presence or absence of radiographic OA in the contralateral joint, participants were categorized as having bilateral or unilateral OA. If radiographic OA of different finger joints was present, participants were categorized as having generalized OA. Odds ratios and 95% confidence intervals for the association of serum cholesterol with OA patterns were calculated with logistic regression, adjusting for potential confounders.

Eighty-five percent of participants with radiographs had bilateral OA and 26% generalized OA. No association was observed between hypercholesterolemia and bilateral OA. Hypercholesterolemia (OR 1.61; 95% CI 1.06-2.47) and high serum cholesterol levels (3rd versus 1st tertile: OR 1.73; 95% CI 1.02-2.92) were independently associated with generalized OA. This association was almost exclusively due to participants with knee OA.

These data add to the evidence regarding the independent role of serum cholesterol as a systemic risk factor for OA. The discrepant associations observed for different OA patterns are likely due to the relative weight of other risk factors.