Non-diabetic metabolic syndrome and obesity do not affect serum paraoxonase and arylesterase activities but do affect oxidative stress and inflammation

Objective: Paraoxonase-1 (PON-1), which has PON and arylesterase activities, is a high-density lipoprotein (HDL)-bound antioxidant enzyme that inhibits atherosclerosis. Diabetes has been shown to have an impact on oxidative stress. The effect of metabolic syndrome (MetS) on oxidative stress and PON-1 has been shown before, and PON-1 has been found to be related with accelerated atherogenesis. This study aimed to determine the oxidative state and PON and arylesterase activities in non-diabetic MetS and non-MetS obese patients. Design: Thirty obese patients (3 M and 27 F) without MetS, 40 non-diabetic obese patients (3 M and 37 F) with MetS, and 30 controls (2 M and 28 F) were enrolled. Methods: A 75 g glucose tolerance test was performed. PON-1, PON, arylesterase, total antioxidant status (TAS), high-sensitive C-reactive protein (hsCRP), and metabolic parameters were analyzed. Results: PON and arylesterase activities were similar between the groups, while TAS was low in both MetS and obese groups compared to controls (P<0.01 and P<0.05 respectively). CRP was higher in the MetS group compared with the obese and control groups (P<0.01 and P<0.001 respectively). In both the obese and MetS groups, CRP showed a positive correlation with body mass index (BMI). TAS was negatively correlated with BMI, waist circumference, triglyceride levels, and systolic and diastolic blood pressures (P<0.001). Conclusions: Oxidative stress is altered in non-diabetic MetS and non-MetS obese patients, but PON and arylesterase activities seem not to be affected. This result may be due to the absence of diabetes, the most severe form of altered carbohydrate metabolism.