Vascular function in obese children with non-alcoholic fatty liver disease

OBJECTIVE: To test whether obese children with non-alcoholic fatty liver disease have impaired vascular function compared with obese children with normal liver fat content. METHODS: Obese children (n = 28, 16 males, mean age 10.9 ± 0.7 years, body mass index BMI 31.9 ± 4.5 kg/m(2)) with normal (HCLn) and increased hepatocellular lipid content (HCLi, 2.6 ± 0.8 vs. 12.4 ± 8.2%) were recruited, outcome measures being flow-mediated dilation of the brachial artery FMD measured by ultrasound, biochemical markers of inflammation (hs-CRP, hs-IL6) and cell adhesion molecules CAMs, hepatocellular lipids, visceral and subcutaneous fat quantified by nuclear magnetic resonance spectroscopy and imaging. RESULTS: HCLi and HCLn groups showed no significant differences in terms of age, gender, BMI, waist circumference and subcutaneous fat. Subjects in the HCLi group had significantly higher amounts of visceral fat and higher fasting glucose, insulin and triglyceride, but lower adiponectin levels and were more insulin resistant than their HCLn controls. Hepatic fat fraction (HFF) correlated positively with fasting plasma glucose, HOMA-IR, adiponectin, visceral fat, negatively with WBISI independent of BMI. HFF was not associated with subcutaneous fat, fasting insulin, FFA, HDL-C, TG, hs-CRP, hs-IL6, vCAM, iCAM, and FMD. HCLi patients had significantly higher serum levels of hs-CRP and hs-IL6 than HCLn controls. FMD and serum levels of vCAM and iCAM were comparable between groups. CONCLUSIONS: Obese children with simple steatosis rather than steatohepatitis seem to have intact vascular function. Further studies in obese children with different grades of NAFLD are warranted to elucidate the role of fatty liver as a marker of risk for future cardiovascular events.