Measurement of glycosaminoglycans in canine synovial fluid and its correlation with the cause of secondary osteoarthritis, age and body weight

Abstract

Glycosaminoglycans are natural components of healthy joint cartilage and they also appear in healthy synovial fluid. An increased amount of glycosaminoglycans in synovial fluid is believed to be a marker of secondary osteoarthritis, regardless of its primary cause. The aim of our study was to define the relationship between glycosaminoglycans in the synovial fluid and joint disorders, age, and body weight. The samples of synovial fluid were obtained from dogs suffering from secondary secondary osteoarthritis (n = 35) and from control dogs (n = 18); control dogs had normal body weight. The results were compared among joints of dogs with secondary osteoarthritis divided into groups according to the criteria mentioned above and control dogs. Glycosaminoglycan concentrations in synovial fluid were measured using dimethylmethylene blue assay. The lowest mean value of glycosaminoglycans in synovial fluid was measured in the control group. Significantly higher glycosaminoglycan content (P < 0.05) was found in synovial fluid isolated from obese dogs compared to control dogs. Furthermore, we observed an agerelated trend, in which the highest mean values were reached either in old dogs or pups. Despite the absence of significant differences in glycosaminoglycan values among dogs suffering from various types of secondary secondary osteoarthritis, the highest mean values were measured in fragmented coronoid processus group. Our data suggest that abnormally increased body weight has an impact on glycosaminoglycan concentration in synovial fluid which may imply faster degradation and turnover of joint cartilage. Such observation has not yet been published in veterinary medicine.

Canine synovial fluid biomarkers for early detection and monitoring of osteoarthritis

“…In contrast, Johnson and others (2002) reported no significant difference between sGAG levels in stifles with naturally occurring CCLR and normal stifles (Tables 3). Corroborating these results, a more recent study observed a non‐significant, yet increasing trend in sGAG concentration from patients with OA in various affected joints (Andrysikova and others 2012) (Table 4). An important note concerning the comparison and interpretation of this biomarker is that sGAG gradually decreases with progression of OA and finally becomes normal again (Andrysikova and others 2012).…”

“…Corroborating these results, a more recent study observed a non‐significant, yet increasing trend in sGAG concentration from patients with OA in various affected joints (Andrysikova and others 2012) (Table 4). An important note concerning the comparison and interpretation of this biomarker is that sGAG gradually decreases with progression of OA and finally becomes normal again (Andrysikova and others 2012). Obesity also affects its concentration in synovial fluid: an excessive bodyweight has a negative impact on cartilage and therefore results in an increased release of sGAG (Andrysikova and others 2012).…”

“…An important note concerning the comparison and interpretation of this biomarker is that sGAG gradually decreases with progression of OA and finally becomes normal again (Andrysikova and others 2012). Obesity also affects its concentration in synovial fluid: an excessive bodyweight has a negative impact on cartilage and therefore results in an increased release of sGAG (Andrysikova and others 2012).…”