Impact of obesity on status of glutathione reductase activity and inflammatory response in patients with knee osteoarthritis.

Obesity is a significant risk factor for developing osteoarthritis (OA). The exact pathogenesis of obesity-associated OA is not completely understood. However, recent studies indicate that pro-oxidant and antioxidant status together with pro-inflammatory factors may contribute to an increase in osteoarthritis risk. Aim of work: : was to investigate glutathione reductase (GR) activity as an antioxidant enzyme and inflammatory markers in obese and non-obese knee osteoarthritic patients Patients and Methods: 36 patients with knee OA (21 obese and 15 non-obese), and 30 age/sex-matched controls were enrolled in this study. Western Ontario and Mc-Master University( WOMAC) score and pain were assessed. Radiological grading of knee joints by Kellgren and Lawrence (KL) score was performed. Blood samples were collected and analyzed for GR, lipid profile,C reactive protein( CRP), and interleukin-6 (IL-6). Results: Plasma activity of GR was significantly higher in controls than OA patients (obese and non-obese) (P=0.001, ?0.05 respectively) with more lower levels in obese than non-obese OA (p=0.04). On the other hand, Inflammatory markers (IL-6 and CRP) were significantly higher in obese OA patients than controls (P?0.001) and in obese than non obese OA(P?0.001). In obese OA group significant correlation was found between IL-6 and BMI. In addition, age correlated with KL scoring of knee, and CRP with serum cholesterol level. In non-obese OA group only WOMAC score correlated significantly with BMI (P=0.041). Conclusion: The results of this study suggest higher oxidative stress status in OA, evidenced by decreased GR activity. Association of obesity with OA adds a marked oxidative burden and inflammatory status on the joint much more than OA per se.