Increased plasma isoprostane is associated with visceral fat, high molecular weight adiponectin, and metabolic complications in obese children

Abstract

Oxidative stress is considered to be increased in obese subjects. However, the association of oxidative stress with visceral adiposity and adiponectin level is not fully understood in children. Forty-four obese Japanese children and adolescents, 28 boys and 16 girls, with median age of 9.9 years [5.2–13.8 years], and the 28 age-matched non-obese healthy controls, 15 boys and 13 girls, were enrolled in this study. The median BMI Z scores were +2.21 [1.31–4.38] for the obese subjects and −0.72 [−2.11–1.31] for the control. Plasma concentrations of 8-epi-prostaglandin ${{\hbox{F}}_{2\alpha }}$ (isoprostane), a marker of oxidative stress, and adiponectin fractions were assayed using ELISA. 8-epi-PGF$_{2\alpha }$ levels were significantly higher in the obese group (37.1 [4.7–112.7], median and the range) than in the control (11.5 [4.5–27.3]). In a univariate analysis, concentrations of 8-epi-PGF$_{2\alpha }$ positively correlated with visceral adipose tissue area measured by computed tomography, waist circumference, serum triglycerides, alanine aminotransferase, insulin levels, and the homeostasis of minimal assessment of insulin resistance and inversely correlated with high-density-lipoprotein cholesterol and high-molecular weight (HMW) adiponectin. Total-, medium-, or low-molecular weight adiponectin fraction did not show a significant correlation with 8-epi-PGF$_{2\alpha }$. Forty of 44 obese children had one or more metabolic complications. The 8-epi-PGF$_{2\alpha }$ levels also elevated with increasing numbers of obesity-related complications. These results suggest that oxidative stress is enhanced in relation to visceral fat accumulation and decreasing HMW adiponectin level in childhood obesity. Oxidative stress may be associated with the development of obesity-related complications.