No abstract

Oxidative stress (OS) is important in the pathogenesis of atherosclerosis. Paraoxonase-1 (PON1) is an enzyme found in the circulation associated with high-density lipoprotein (HDL). HDL-associated enzyme PON1 has an important role in the attenuation of atherogenic low-density lipoprotein (LDL) oxidation. The aim of this study was to determine PON1 and arylesterase (AREST) enzyme levels in relation to insulin resistance (IR) or obesity among children and adolescents. The study included healthy school children and adolescents. Blood was drawn for the determination of blood glucose, lipid, PON1 and AREST enzyme levels. Overall, we observed a positive correlation between PON1 enzyme activity and high-density lipoprotein cholesterol (HDL-C) levels (r = 0.189, P = 0.014). The correlation appeared to be more significant in boys (r = 0.271, P = 0.009). For subjects with IR and obesity, PON1 enzyme activity did not correlate with HDL-C levels (r = 0.038, P = 0.790), instead PON1 levels correlated negatively with BMI (r = -0.309 and P = 0.026). Multiple linear regression analysis was performed to find the predictors of log PON1 activity. HDL-C level was the strongest predictor of PON1 activity in the lean control group, while BMI appeared to be the strongest predictor in the subjects with obesity or IR. In conclusion, determinants of PON1 enzyme activity are variable in children and adolescents based on IR and obesity. Future studies will shed light on the underlying mechanisms and biomarkers of OS in children and may reveal possible targets for therapeutic intervention.

Ağırbaşlı M, Tanrıkulu A, Azizy M. Free estradiol index levels associated with high sensitivitiy CRP levels in male children. Turk J Pediatr 2017; 59: 49-55. Biomarkers of inflammation such as high-sensitivity C-reactive protein (hs-CRP) associate with subclinical atherosclerosis. Atherosclerosis is an early onset disease in life. Sex hormones and puberty modulate metabolism in children. Studies indicate that low sex hormone binding globulin (SHBG) levels associate with insulin resistance and metabolic syndrome in children. The aim of this study is to study the correlation between sex hormones and hs-CRP levels in children and adolescents. The study sample was derived from a cross sectional survey on the prevalence of cardiovascular risk factors in a representative sample of school children (8-17 year-old) in Istanbul, Turkey. In addition to anthropometric and biochemical characteristics of cardiovascular risk, sex hormones such as free androgen index, free estradiol index (FEI), SHBG and hs-CRP levels were measured in all study participants: 91 boys (12.4 ± 3.4 years) and 77 girls (12.7 ± 3.4 years) were included in the study. Median (interquartile range) hs-CRP levels were similar among boys and girls [0.36 (0.9) versus 0.45 (0.7) mg/dl, p= 0.725]. Gender stratified analysis displayed that hs-CRP levels positively correlated with FEI levels (r=0.438, p < 0.001) in boys. Linear regression analysis was performed to determine the predictors of hs-CRP. Among covariates of FEI, homeostasis model assessment-estimated insulin resistance, body mass index, age, and SHBG; FEI was shown to significantly and independently predict hs-CRP levels in boys [β=2.758, p < 0.001, 95% confidence interval (CI) for β 1.471-4.045]. FEI levels associate with subclinical inflammation in boys. Future studies may elucidate the role of sex hormone levels in inflammation among children.