Abstract

Objective: To explore whether an imbalance between the visceral and subcutaneous fat depots, and a corresponding dysregulation of the adipokine milieu, is associated with excessive accumulation of fat in the liver and muscle and ultimately with insulin resistance and the metabolic syndrome.

Research Design and Methods: We stratified our multi-ethnic cohort of 118 obese adolescents into tertiles based on the proportion of abdominal fat in the visceral depot. Abdominal and liver fat were measured by MRI and muscle lipid (IMCL) by ¹H-MRS.

Results: There were no differences in age, BMI z-score, or fat-free mass across tertiles. However, as the proportion of visceral fat increased across tertiles, BMI, percent fat and subcutaneous fat decreased, while hepatic fat increased. In addition, there was an increase in 2-hr glucose, insulin, c-peptide, triglyceride levels, and insulin resistance. Notably, both leptin and total adiponectin were significantly lower in tertile 3 than 1, while CRP and IL-6 were not different across tertiles. There was a significant increase in the odds ratio for the metabolic syndrome, with subjects in tertile 3 being 5.2 times more likely to have the metabolic syndrome than those in tertile 1.

Conclusions: Obese adolescents with a high proportion of visceral fat and relatively low abdominal subcutaneous fat have a phenotype reminiscent of partial lipodystrophy: liver steatosis and a greater risk of having the metabolic syndrome.