Evaluation of paraoxonase 1 arylesterase activity and lipid peroxide levels in patients with type 1 diabetes.

INTRODUCTION Poor metabolic control of type 1 diabetes is one of the most important factors accelerating the development of late diabetic complications. Several other factors that might contribute to this process are currently being investigated. Low paraoxonase 1 (PON1) activity and high lipid peroxide (LPO) levels contribute to endothelial damage, but it remains unclear whether they are critical for the development of late diabetic complications. OBJECTIVES The aim of the study was to evaluate PON1 arylesterase activity and LPO levels in patients with type 1 diabetes and to investigate whether these parameters are associated with metabolic control and late complications. Moreover, we aimed to establish whether PON1 activity and LPO levels differ between women and men with type 1 diabetes. PATIENTS AND METHODS The study involved 80 patients with type 1 diabetes and 24 healthy subjects. PON1 activity was measured by a spectrophotometric method. LPO levels were measured by a commercial assay kit. RESULTS Diabetic patients had lower PON1 activity and higher LPO levels than healthy people. We observed a negative correlation between PON1 activity and LPO levels in diabetic patients. There was no association between PON1 activity or LPO levels and metabolic parameters or late diabetic complications. There was a positive correlation between LPO levels and the body mass index (BMI) in women with type 1 diabetes. CONCLUSIONS Our study showed that low PON1 activity and high LPO levels are not the most critical factors involved in late diabetic complications in type 1 diabetes. Increased LPO levels in women with type 1 diabetes may result from enhanced lipogenesis in this subgroup compared with diabetic men.