Association between asymptomatic hyperuricemia and knee osteoarthritis in older outpatients

To investigate the association between asymptomatic hyperuricemia and knee osteoarthritis in older outpatients in Vietnam.

This cross-sectional study included 257 older outpatients (195 in the knee osteoarthritis group and 62 in the non-knee osteoarthritis group) aged ≥60 years (mean age 73.31 ± 7.96 years) attending rheumatologic and geriatric clinics from November 2020 to May 2021. Data were collected for both groups, including demographics, symptoms and signs of knee osteoarthritis, serum uric acid levels, and knee radiographs. The association between asymptomatic hyperuricemia and knee osteoarthritis was assessed using logistic regression.

The mean serum uric acid level among patients with knee osteoarthritis was higher than that among patients without knee osteoarthritis (6.3 ± 1.74 mg/dl vs. 5.71 ± 1.45 mg/dl, p = 0.017). Hyperuricemia was more common among older outpatients with knee osteoarthritis than among those without knee osteoarthritis (39% vs. 19%, p = 0.005). After adjusting for age, sex, body mass index (BMI), and other comorbidities, the association between asymptomatic hyperuricemia and knee osteoarthritis remained significant (odds ratio [OR] 2.61, 95% confidence interval [CI] 1.22-5.60, p = 0.013). Subgroup analyses were performed according to sex and BMI groups. Significant associations between asymptomatic hyperuricemia and knee osteoarthritis were observed among women (p = 0.017) and among individuals who were underweight-normal-weight according to BMI (p = 0.009).

Asymptomatic hyperuricemia is a common comorbidity among older outpatients with knee osteoarthritis. An independent association was identified between asymptomatic hyperuricemia and knee osteoarthritis among older Vietnamese outpatients, although sex and BMI may be confounding factors that impact this association.