Intrahepatic fat accumulation and alterations in lipoprotein composition in obese adolescents: a perfect proatherogenic state.
OBJECTIVE
Among other metabolic consequences, a dyslipidemic profile often accompanies childhood obesity. In adults, type 2 diabetes and hepatic steatosis have been shown to alter lipoprotein subclass distribution and size; however, these alterations have not yet been shown in children or adolescents. Therefore, our objective was to determine the effect of hepatic steatosis on lipoprotein concentration and size in obese adolescents.


METHODS
Using fast magnetic resonance imaging, we measured intrahepatic fat content in 49 obese adolescents with normal glucose tolerance. The presence or absence of hepatic steatosis was determined by a threshold value for hepatic fat fraction (HFF) of 5.5%; therefore, the cohort was divided into two groups (HFF > or <5.5%). Fasting lipoprotein subclasses were determined using nuclear magnetic resonance spectroscopy.


RESULTS
Overall, the high-HFF group had 88% higher concentrations of large VLDL compared with the low-HFF group (P < 0.001). Likewise, the high-HFF group had significantly higher concentrations of small dense LDL (P < 0.007); however, the low-HFF group had significantly higher concentrations of large HDL (P < 0.001). Stepwise multiple regression analysis revealed that high HFF was the strongest single correlate, accounting for 32.6% of the variance in large VLDL concentrations (P < 0.002).


CONCLUSIONS
The presence of fatty liver was associated with a pronounced dyslipidemic profile characterized by large VLDL, small dense LDL, and decreased large HDL concentrations. This proatherogenic phenotype was strongly related to the intrahepatic lipid content.
Cali
Anna M G
AM
Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut 06520, USA.
Zern
Tosca L
TL
Taksali
Sara E
SE
de Oliveira
Ana Mayra
AM
Dufour
Sylvie
S
Otvos
James D
JD
Caprio
Sonia
S
D000273:Adipose Tissue / Q000473:pathology*; D000293:Adolescent; D050197:Atherosclerosis / Q000453:epidemiology* / Q000473:pathology; D015992:Body Mass Index; D006801:Humans; D008055:Lipids / Q000032:analysis; D008074:Lipoproteins / Q000097:blood*; D008099:Liver / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D009765:Obesity / Q000097:blood* / Q000150:complications / Q000473:pathology*; D012016:Reference Values
D008055:Lipids; D008074:Lipoproteins