Association of increased reactive oxygen species production with abdominal obesity in type 2 diabetes

Objective: The close relationship between oxidative stress and abdominal obesity is well known, but the association is unclear in diabetic patients. The aim of this study was to confirm that increased reactive oxygen species (ROS) production is associated with abdominal obesity in diabetic patients. Methods: ROS production was assayed in Epstein-Barr virus-transformed immortalized lymphoblasts by means of a cypridina luciferin analogue chemiluminescence method. We divided 96 Japanese male diabetic patients into 2 groups: patients with abdominal obesity according to the accepted Japanese criteria (waist circumference is more than 85 cm) (group AO, n = 36); and patients without abdominal obesity (group N, n = 60). Subjects with body mass index (BMI) in the normal range (21 ≤ BMI < 25 kg/m²) were then selected and assigned to 2 subgroups (group AO_normal-BMI [n = 13]; and group N_normal-BMI [n = 35]); ROS production was compared between these 2 subgroups. Results: Stimulation with arachidonic acid (AA) and 12-O-tetradecanoylphorbol-13-acetate (TPA) increased ROS production in lymphoblasts, which was more greatly elevated in lymphoblasts derived from group AO than those from group N. Even in the subjects with normal BMI, AA- and TPA-stimulated ROS production in group AO was significantly higher than that in group N. Conclusions: These data suggest that increased ROS production is more closely associated with abdominal obesity than high BMI or insulin resistance in diabetic patients.