Relationship Between Serum Levels of Oxidized Lipoproteins, Circulating Levels of Myeloperoxidase and Paraoxonase 1, and Diet in Young Subjects with Insulin Resistance

Oxidized low-density lipoproteins (ox-LDLs) are involved in atherosclerotic plaque formation and progression and have been linked to insulin resistance (IR). Myeloperoxidase is a potent oxidant of lipoproteins related to atherogenic risk. High-density lipoproteins (HDLs) are considered antioxidants due to their association with paraoxonase 1 (PON1). However, HDL can also be oxidized (ox-HDL), and its relationship with IR has not been described. This study evaluated the relationship between circulating levels of myeloperoxidase and paraoxonase 1, diet, and serum levels of ox-LDL and ox-HDL in young people with IR. This cross-sectional study examined 136 young subjects (67 and 69 with and without insulin resistance, respectively). Serum levels of ox-LDL, ox-HDL, myeloperoxidase, and PON1 were quantified using an enzyme-linked immunosorbent assay. The nutritional dietary content of the foods was determined with a food frequency questionnaire, which was analyzed with Nutrimind 2013 software. Serum ox-HDL levels were higher in young subjects without IR than those with IR (<i>p</i> = 0.031). Women with IR presented increased ox-LDL levels compared with women without IR (<i>p</i> = 0.012) and men with IR (<i>p</i> < 0.001). In the IR group, serum ox-LDL levels were negatively correlated with total cholesterol, triglycerides, and LDL-C, whereas the correlation was positive in the insulin-sensitive group. Consumption of vitamins B1 and B2 was related to increased HDL-C levels, while higher ox-LDL levels were related to vitamin K intake. In addition, low energy consumption and phosphorus increased PON1 levels. The results suggest that insulin resistance in young women may promote lipoprotein oxidation, and the intake of B complex vitamins may have an antiatherogenic effect.