Serum and dietary antioxidant status is associated with lower prevalence of the metabolic syndrome in a study in Shanghai, China.

OBJECTIVE: The aim of our study was to examine the association between the metabolic syndrome (MS) and serum antioxidant status.

METHODS: A cross-sectional study was conducted with 221 cases and 329 controls aged 18 to 65 years. Weight, height, body mass index, waist circumference, blood pressure, fasting blood glucose and lipids, as well as serum superoxide dismutase, glutathione peroxidase, malondialdehide, vitamins A, E, β-carotene and lycopene were examined. Intakes of antioxidants were also estimated.

RESULTS: Mean serum superoxide dismutase activity, β-carotene concentrations were significantly lower, malondialdehide was higher (p<0.05) in persons with the MS (after adjusting for age, sex) than those without. Superoxide dismutase, glutathione peroxidase, and β- carotene also decreased significantly (p<0.05) with increased number of components of the MS. Low levels of serum superoxide dismutase activity and β-carotene concentration appeared to be associated with the MS status. Moreover, dietary energy, carbohydrate, vitamin C, zinc and copper intake in the MS patients were lower, but fat intake were higher. Vitamins E, C and manganese intake decreased with the elevated number of the MS components. For zinc and manganese, a lower risk was observed for other quartile of intake compared with the first one. Inverse links between dietary fat, energy intake and serum antioxidant status were found in MS patients, meanwhile dietary vitamin C was positively related with serum antioxidant level.

CONCLUSIONS: Serum antioxidant status was associated with a lower prevalence of the MS, and with lower dietary fat, energy intake and higher vitamin C intake.