Oxidative stress constitutes an important risk factor for tissue/cell damage and is involved in the occurrence and progression of Osteoarthritis (OA).
The aim of this study was to evaluate the concentration of Malondialdehyde (MDA) in Synovial Fluid (SF) and blood as well as the activity of serum and SF paraoxonase (PON1) of patients with OA. Our study aimed to assess local and systemic responses to oxidative stress.
The study included 43 subjects with OA qualified to total joint replacement. The control group consisted of 58 subjects with no musculoskeletal disorders. The malondialdehyde level were measured in venous blood plasma, erythrocytes (MDAe) and Synovial Fluid (SF) while PON1 activities were estimated in serum and SF.
No differences in MDA concentrations in erythrocytes and blood plasma between healthy subjects and OA patients were observed. The significant higher level of MDA in SF compared with blood serum was seen in both genders (in woman about 46.2%, in men - 75.0%) and in both assessed joints (in hip about 53.8%, in knee - 115.9%). Total protein concentration and PON1 activity in serum were significantly higher in OA patients (about 14.6% and 87.9% respectively). The systemic response to osteoarthritis (serum PON1 activity) was higher about 33.6% in men than women and not dependent on affected joint.
The changes observed in osteoarthritic SF show that the process of antioxidant enzymatic defence is intensified locally, not systemically. The lipid hydroperoxides elimination may lead to restore joints homeostasis.