Association of Serum Uric Acid with the Severity of Knee Osteoarthritis in a Tertiary Care Hospital

Background: Osteoarthritis (OA) is the most common musculoskeletal condition and the most common cause of activity limitation among the middle aged and elderly population. Uric acid (UA) is constitutively present in normal cells, increased in concentration when cells are injured, and released from dying cells. Reaction of UA with oxidizing species generates UA radicals which is capable of causing biological damage. Several studies have previously showed an association between raised uric acid level and OA. Objectives: The objectives of this study were to determine the correlation between serum uric acid level and radiological severity of knee osteoarthritis according to Kellgren-Lawrence grading. Methods: This was a cross sectional study done among 80 cases of knee osteoarthritis for the period from August 2017 to May 2018 in Department of Physical Medicine and Rehabilitation, Bangabandhu Sheikh Mujib Medical University, (Shahbagh, Dhaka). Correlation between serum uric acid level and severity of knee osteoarthritis was made by Spearman’s rho correlation. Continuous variables were tested with paired t-tests. Ordinal variables were tested with Wilcoxon signed rank test. Results: Mean serum Uric Acid was 6.08 ± 1.11 mg/dl in male and 5.99 ± 0.97 mg/dl in female patients. Majority of the patients (42.5%) suffered from Grade 3 knee osteoarthritis radiologically. Maximum uric acid level was found (6.53 ± 1.54) in Grade 4 osteoarthritis. Mean Serum Uric acid Level was 5.85 ± 0.28 in Grade 3 and 5.52 ± 0.47 in Grade 2 knee osteoarthritis. Serum Uric acid level with severity of knee osteoarthritis Spearman’s rho correlation was done. There was significant correlation between severity of knee osteoarthritis and serum uric acid (rs=+0.288; p=0.013). Conclusions: Serum uric acid levels are significantly related to the radiological severity of knee osteoarthritis. The level of serum UA was found to be in increasing order, parallel to the grades of the disease.