Objectives In this study we aimed to measure plasma adiponectin concentrations in obese and non-obese patients with knee osteoarthritis and to investigate the relation between plasma levels of adiponectin with clinical and radiological disease severity.
Methods Sixty patients with knee osteoarthritis and twenty-five healthy controls were included in the study. Patients were divided into two groups. Group 1 (n=30) was the non-obese patients group with body mass index (BMI)<24.9 and group 2 (n=30) was the obese patients group with BMI>29.9. Healthy controls were accepted as group 3 (n=25). Patients were clinically evaluated by means of pain, functional disability, quality of life(QoL). Pain intensity was measured with visual analog scale(VAS), functional disability with Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and QoL with short form 36 (SF-36). Also all patients were radiologically evaluated and graded according to Kellgren Lawrence(KL) scale by anteroposterior knee radiography. Fasting blood serum were collected from both patient and control groups to measure plasma concentrations of adiponectin by enzyme-linked immunosorbent assay (ELISA). Additionally, sedimentation rate, CRP, and RF were measured from the same blood sample.
Results Serum adiponectin levels were significantly higher in OA patients than the control group (group 1= 123.54 ± 85.08, group 2=100.61 ± 57.34, group 3= 65.47 ± 39.36 p=0.018). There were no statistically significant differences between group 1 and 2 (p=0.487). There was a statistically significant correlation between adiponectin concentration and KL grading scores which means higher grades have higher adiponection levels. Additionally, there was a positive correlation between adiponectin levels, WOMAC total scores and VAS in OA patients independent of age and BMI (respectively r=0.583 p=0<001, r=0.326 p=0.012). SF-36 scores were inversely associated with adiponectin levels. There were no statistically significant correlation between sedimentation rate, CRP, RF levels of plasma and adiponectin concentration(p>0.05). In contrast to high adiponectin level with low BMI in healthy controls, we could not find any significant correlation between them in knee OA patients.
Conclusions According to this pilot study results, plasma adiponectin concentrations were elevated in knee osteoarthritis patients and associated with both clinical and radiological disease severity. Thus, adiponectin levels can be taken into consideration in assessing disease severity in daily practice in future.
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Disclosure of Interest N. Cüzdan Coşkun Grant/research support from: TLAR-Turkish League Against Rheumatism, S. Ay: None Declared, D. Evcik: None Declared, D. Oztuna: None Declared