Objective: Serum hyaluronan (sHA) is one of the leading biomarkers for knee osteoarthritis (OA). Although sHA levels increase in patients with knee OA, there has been little research regarding the association with knee symptoms related to OA. The purpose of this study was to investigate the relationship between sHA levels and changes of knee symptoms during a 3-year prospective cohort study.
Methods: There were 331 individuals (124 males and 207 females) from the general population who participated in an annual check-up project from 2008 to 2011, inclusive. Participants were stratified into three groups: low, middle and high, according to their sHA levels at entry into the study in 2008. Radiographic knee OA was graded according to the Kellgren-Lawrence (K-L) system, and grades 0 and 1 were defined as normal, grade 2 as moderate, and grades 3 and 4 as severe. Knee symptoms and function were evaluated by the Knee Injury and Osteoarthritis Outcome Score (KOOS). Changes of KOOS among the three groups were compared statistically.
Results: Prevalence of OA was 86 out of 331 subjects. Cross-sectional analysis at baseline showed that sHA levels increased with the severity of radiographic knee OA and knee symptoms. All subscales of KOOS significantly decreased with increasing sHA levels,with their correlation coefficients ranging from −0.20 to −0.41. Longitudinal analysis showed that KOOS Pain and activities of daily living (ADL) in the high group decreased 1 year after, and KOOS Symptom decreased gradually, while the values of the middle and low groups were maintained. Also, those individuals with higher sHA levels had worsening KOOS pain, ADL and sports scores.
Conclusion: Higher sHA levels are associated with worsening of knee symptoms as well as the severity of radiographic knee OA. Our results show that sHA is a potential predictor for worsening of knee OA symptoms.
