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.

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.

AIM

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.

CONCLUSION

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.