Fasting Lipid, Inflammatory And Oxidative Stress Associations with Vascular Function In Pre- And Early-pubertal Children

Abstract

Elevated lipids and inflammatory and oxidative stress markers are associated with reduced vascular health in older teens and adults. The impact of obesity on these markers and on vascular function in young children is unclear. PURPOSE: To determine the impact of fasting lipids, insulin, inflammatory and oxidative stress markers on vascular structure and function in pre- and early-pubertal children. METHODS: 26 lean (n=12) and obese (n=14) children (10.2±1.6 yrs, 15M/11F, Tanner 1-2) were studied after a 12hr fast. Glucose, insulin, FFA, TG, cholesterol, HDL, CRP, IL6, TNFa, oxLDL were tested using standard assays, and insulin resistance by HOMA. Flow mediated dilation (FMD) and carotid intima media thickness (IMT) were measured by ultrasound scans. Tanner stage and baseline vessel diameter were used as covariates in comparing lean/obese groups. Significance at p<0.05, mean ± sem presented. RESULTS: As expected, obese were heavier (56±3 vs 32±2kg, p<0.0001) with greater body fat % (46±1 vs 31±2%, p<0.0001) than lean. Insulin (24±5 vs 10±1uU/ml, p<0.05), CRP (4±1 vs 0.3±0.1mg/L, p<0.01) were higher, and HDL lower (43±2 vs 51±3mg/dl, p<0.05) in obese than lean. Glucose, FFA, TG, cholesterol, IL6, TNFa, oxLDL did not differ by group. There were no group differences in IMT or FMD, nor in HOMA (p=0.07). We found no association between fasting insulin, CRP or HDL with vascular measures in either group. CONCLUSIONS: Although obese had greater adiposity, insulin and CRP with lower HDL, there were no differences in vascular structure and function in these young children like that seen in obese versus lean adolescents and adults. This in combination with a lack of association between circulating lipids, inflammatory and oxidative stress markers with FMD suggests that prior to the onset of puberty, blood vessels in young children may not yet be impacted by aberrant circulating markers. It may be that the development of insulin resistance and increased sex hormone levels that occur during the pubertal transition may play a critical role in the early development of cardiovascular risk factors. Thus it is crucial to reduce detrimental factors prior to the onset of puberty so that early CV risk factor development might be avoided. Support: UCD CTSI (NIH M01RR00069 & M01RR00051), Childrens Hospital Research Institute, Thrasher Foundation