title: Normal-weight 14-year-old girl with acanthosis nigricans and markedly increased hepatic steatosis: evidence for the important role of ectopic fat deposition in the pathogenesis of insulin resistance in childhood and adolescence.
abstract: BACKGROUND
  A major factor in the development of insulin resistance is obesity. While the contribution of intrahepatic lipids to insulin resistance is well established in adults, there are only few reports in childhood and adolescence.
  
  
  OBJECTIVE
  To investigate the correlation between ectopic fat deposition and insulin sensitivity in a normal-weight girl with acanthosis nigricans before and after lifestyle intervention.
  
  
  METHODS
  Variations in body fat composition and intrahepatic lipids were monitored by means of anthropometric measures and by means of methods based on magnetic resonance imaging and magnetic resonance spectroscopy.
  
  
  RESULTS
  We present the case of a normal-weight 14-year-old Caucasian girl with pronounced hepatic steatosis together with acanthosis nigricans, increased waist-circumference and increased visceral fat. During a 7-month period of lifestyle intervention, the girl lost 7.1 kg in weight. Acanthosis nigricans, whole-body insulin sensitivity index (WBISI) and homeostasis model assessment (HOMA) improved significantly (before intervention: WBISI 0.42, HOMA 22.2; after intervention: WBISI 1.35, HOMA 6.9). Even though all lipid compartments were decreased in size, the intrahepatic lipids showed an extraordinarily great reduction.
  
  
  CONCLUSIONS
  This case presentation of a normal-weight girl with acanthosis nigricans and markedly increased hepatic steatosis provides support for the association between intrahepatic fat deposition and insulin resistance in adolescence.
authors.affiliation: Section on Experimental Radiology, Department of Diagnostic and Interventional Radiology, University Hospital Tübingen, Tübingen, Germany.
authors.forename: Fabian
authors.initials: F
authors.lastname: Springer
authors.forename: Huu Phuc
authors.initials: HP
authors.lastname: Nguyen
authors.forename: Jürgen
authors.initials: J
authors.lastname: Machann
authors.forename: Roland
authors.initials: R
authors.lastname: Schweizer
authors.forename: Michael B
authors.initials: MB
authors.lastname: Ranke
authors.forename: Gerhard
authors.initials: G
authors.lastname: Binder
authors.forename: Fritz
authors.initials: F
authors.lastname: Schick
authors.forename: Stefan
authors.initials: S
authors.lastname: Ehehalt
mesh_terms: D000052:Acanthosis Nigricans / Q000150:complications / Q000378:metabolism / Q000473:pathology*; D000273:Adipose Tissue; D000293:Adolescent; D015992:Body Mass Index; D001835:Body Weight / Q000502:physiology; D002828:Choristoma / Q000473:pathology*; D004032:Diet; D005234:Fatty Liver / Q000150:complications / Q000473:pathology*; D005260:Female; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology*; D008019:Life Style; D009043:Motor Activity / Q000502:physiology; D011627:Puberty / Q000502:physiology; D049629:Waist-Hip Ratio