Correlation between serum leptin,cytokines, cartilage degradation and functional impact in obese knee osteoarthritis patients

Aim of the workThe aim of the present work was to correlate between serum level of leptin, matrix metalloproteinase-13 (MMP13), interleukin-1β (IL1β), tumour necrosis factor (TNF-α), nitric oxide (NO) and functional impact in obese patients with knee osteoarthritis (KOA).Patients and methodsThe study included 84 obese patients suffering from primary KOA. The knees were examined; pain assessed by visual analogue scale (VAS) and Lequesne’s index for functional impact calculated. Serum leptin, MMP13, IL1β, TNF-α and NO were assessed.ResultsThe mean age of the patients was 54.64 ± 7.7 years. They were 72 females and 12 males (F:M = 6:1) with a mean BMI of 35.29 ± 4.8. Sixty patients had knee effusion which was bilateral in 54 (64.3%), unilateral in 6 (7.2%) while 24 (28.6%) did not have any effusion. Knee deformities were present in 60 (71.4%) patients. Female patients were only significantly higher than males regarding Lequesne’s index (15.08 ± 4.4 vs 11 ± 3.4, p = 0.003). Patients with knee deformity had significantly higher VAS (9.12 ± 1.3 vs 6.96 ± 0.46, p = 0.001), IL1β (621.1 ± 98.8 vs 503.9 ± 74.6 pg/ml, p = 0.001), TNF-α (115.4 ± 29.1 vs 87.4 ± 4.4 pg/ml, p = 0.001), NO (67.32 ± 5.7 vs 59.2 ± 2.2 μmol/L, p = 0.001), MMP13 (33.98 ± 2.24 vs 30.1 ± 1.7 ng/ml, p = 0.012) and leptin (13.2 ± 1.6 vs 10.4 ± 0.6, p = 0.004) than those without. The VAS, Lequesne index, IL1β, TNF-α NO, MMP13 and leptin were significantly higher in patients with bilateral knee effusion (p < 0.0001 for all) compared to those with unilateral effusion or without. Leptin significantly correlated with BMI, VAS, Lequesne’s index, IL1β, TNFα, NO and MMP13 (p < 0.0001 for all).ConclusionLeptin plays a key role in obese patients with knee OA. It significantly correlates with knee pain, functional impairment, inflammatory cytokines and cartilage degradation.