Background/Purpose: The strength of association between obesity and osteoarthritis (OA) is reported to vary by joint (e.g. stronger association with knee than hip). As well, the association between obesity and non weight-bearing joints, such as the hands, suggests that systemic/metabolic factors are involved. The presence of multiple symptomatic joints among individuals with severe OA in at least one joint further suggests likely systemic factors in OA. Given known associations between systemic/metabolic factors and cardiovascular disease (CVD) risk, this study investigated the likelihood of reporting CVD between those with hip vs. knee OA, and further considered if the number of symptomatic joints influenced this likelihood.

Methods: Patients with severe OA (443 hip; 540 knee) reported CVD, diabetes, high blood pressure (HBP), symptomatic joints, height, weight, age and sex. The cross-sectional association between study measures and prevalent CVD was investigated using logistic regression, with the inclusion of an interaction term between symptomatic joint count and knee/hip group membership. Subsequently, the analysis was stratified by knee/hip.

Results: Knee: ages 41-88 years, 64% female, 4% CVD, 14% diabetes, 50% HBP. Hip: ages 40-91 years, 55% female, 5% CVD, 9% diabetes, 43% HBP. Mean joint count was 5 (±4), ranging from 1-20.  Adjusted for age, sex, body mass index, and presence of diabetes or HBP, the knee cohort had odds 4 times greater than hips for reporting CVD (p<0.01). There was a significant interaction between joint count and knee/hip group status, such that the effect of increasing joint count was greater for the hip cohort. From stratified analyses, joint count was associated with CVD in the hip cohort only, with a 25% increased odds with each numerical increase in symptomatic joint count (odds ratio (OR): 1.25, p<0.001). In the knee cohort, the presence of diabetes or HBP was significantly associated with reporting CVD (OR: 3.74, p=0.02), whereas a similar association was not found in the hip cohort (OR: 1.23, p=0.68).

Conclusion: The variable association observed with CVD between hip and knee OA, alongside the differential influence of the extent of symptomatic joint involvement between joint groups suggests different OA phenotypes, with potentially varying roles for systemic factors. This has potential implications for our understanding of OA, and suggests a potential need for multimodal approaches to treatment and management.

---

« Back to 2013 ACR/ARHP Annual Meeting

ACR Meeting Abstracts - https://acrabstracts.org/abstract/cardiovascular-disease-in-osteoarthritis-hip-versus-knee-and-the-influence-of-multiple-symptomatic-joint-involvement/