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

Abstract

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/m²) 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.

Key words::

• Obesity
• liver disease
• endothelial
• children

Acknowledgements

We thank all participants and their parents in the study, the staff of the Department of Pediatrics at Vienna Medical School, Martina Gantschacher and Maya Delivuk for excellent assistance, and Neil Jones for proof-reading the manuscript. This study was also supported by grants to KW by Numico Research and MR by EFSD/Novo and the Austrian Science Fund (FWF P1565).

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.