Correlation of serum and synovial leptin concentrations with body condition scores in healthy and osteoarthritic dogs

• Published in: Veterinary surgery Vol. 48; no. 5; pp. 780 - 785
• Main Authors: Kleine, Stephanie A., Sanderson, Sherry L., George, Clinton, Roth, Ira, Gogal, Robert M., Thaliath, Mary Ann, Budsberg, Steven C.
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01-07-2019; Blackwell Publishing Ltd
• Subjects: Anterior cruciate ligament; Arthritis; Biocompatibility; Body weight; Cattle; Dogs; Interleukins; Knee; Leptin; Osteoarthritis; Overweight; Pain; Radiographs; Radiography; Surgery; Synovial fluid
• ISSN: 0161-3499; 1532-950X
• DOI: 10.1111/vsu.13244

Objective
To evaluate the relationship between serum and synovial fluid (SF) leptin concentrations and body condition score (BCS) in healthy and osteoarthritic dogs.
Study design
Controlled, prospective, clinical study.
Animals
Nineteen healthy dogs and 29 dogs with osteoarthritis (OA) secondary to cranial cruciate ligament injury.
Methods
Synovial fluid was obtained from the femorotibial joint under sedation (healthy dogs) or during surgery (OA dogs). Serum and SF leptin and interleukin (IL)‐1β concentrations were measured via enzyme‐linked immunosorbent assay. Dogs were classified as optimal weight (BCS 4–5/9) or overweight (BCS >5/9). Radiographs were scored for OA severity by a radiologist. Owners completed the Liverpool Osteoarthritis in Dogs (LOAD) questionnaire.
Results
Mean (± SD) SF leptin (4.09 ± 4 ng/mL) was lower than serum leptin (6.88 ± 5.52 ng/mL, P < .0001). Synovial fluid leptin was higher in overweight (5.28 ± 4.21) than in optimal body weight dogs (1.54 ± 1.72 ng/mL, P < .0001). Serum (P < .001) and SF leptin (P = .004) concentrations were associated with BCS. Concentration of SF leptin did not differ between healthy (2.4 ± 2.04 ng/mL) and OA (4.9 ± 4.3 ng/mL, P = .25) dogs. Synovial fluid leptin and LOAD scores were weakly associated (P = .03). No association was detected between SF leptin and radiographic score or IL‐1β (P = .73).
Conclusion
Serum and SF leptin correlated with BCS in this population. Synovial fluid leptin was weakly associated with LOAD scores but not with radiographic severity of OA or IL‐1β.
Clinical significance
Serum and SF leptin concentrations do not predict radiographic severity of canine OA but contribute to joint pain and dysfunction.