  Oxidative stress may be associated with the pathophysiology of knee osteoarthritis (OA), a health-care issue. The present study aimed to compare oxidative status levels of patients with and without knee OA, using the Reactive Oxygen Metabolites (d-ROMs, Diacron, Italy) test, which has proved to be clinically useful as an oxidative stress marker.
  Forty-nine women (mean age 71.3 ± 5.8 years, mean body mass index 24.4 ± 2.2 kg/m(2) ) with mildly severe knee OA and 49, without knee OA, female controls' serum d-ROMs concentrations were assessed together with mean blood pressure, fasting plasma glucose and serum total cholesterol concentrations, using the age-, sex- and body mass index-matched method.
  Patients with knee OA showed significantly higher d-ROMs levels than controls (338 ± 56 vs 315 ± 47 U. Carr., P < 0.05). This difference remained statistically significant after adjusting for other clinical variables.
  The present results suggested that knee OA might be an impaired oxidative condition. Further studies are necessary to establish the knee OA-oxidative status relationship, which may lead to its clinical application in the management of knee OA.