Association of Serum Uric Acid Levels with Severity of Knee Osteoarthritis: A Cross-sectional Study
Introduction: Osteoarthritis (OA) of the knee is a common degenerative joint disorder and a leading cause of chronic pain, stiffness and disability among middle-aged and elderly individuals. Serum Uric Acid (SUA) has been suggested as a potential metabolic factor associated with OA severity. Aim: To evaluate the association between SUA levels and the severity of knee OA and to assess their relationship with pain intensity and functional status. Materials and Methods: This cross-sectional observational study was conducted in the Department of Orthopaedics, Maharishi Markandeshwar (MM) Medical College and Hospital, Kumarhatti, Solan, Himachal Pradesh, India, over a period of 18 months (January 2023 to June 2024). A total of 100 patients aged 40-70 years with clinically and radiologically confirmed OA of the knee were included. SUA levels were categorised as normal (<6 mg/dL), moderately elevated (6-8 mg/dL) and high (>8 mg/dL). Pain severity was assessed using the Visual Analogue Scale (VAS), functional status using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and radiological severity using the Kellgren-Lawrence (KL) grading system. Statistical analysis was performed using Stata version 17.0. Associations between variables were assessed using the Pearson’s Chi-square test, Analysis of Variance (ANOVA), while correlation analysis was performed to evaluate the relationship between SUA levels and WOMAC scores. A p-value <0.05 was considered statistically significant. Results: The mean age of the participants was 57.65±5.65 years, with an age range of 48-68 years. Among the 100 participants, 37% had normal SUA levels, 35% had moderately elevated levels and 28% had high SUA levels. A significant association was observed between SUA levels and radiological severity of OA based on KL grading (χ2 =26.21, p=0.006). Higher SUA levels were also significantly associated with greater pain severity on the VAS scale (χ2 =16.15, p=0.013). Mean WOMAC scores increased progressively with rising SUA levels and a strong positive correlation was observed between SUA levels and total WOMAC score (r=0.67, p<0.001). Conclusion: Elevated SUA levels are significantly associated with greater radiological severity, increased pain intensity and poorer functional status in patients with knee OA.