Adipose tissue insulin resistance in adolescents with and without type 2 diabetes

Pediatr Obes. 2014 Oct;9(5):373-80. doi: 10.1111/j.2047-6310.2013.00189.x. Epub 2013 Jul 17.

Abstract

Background: The incidence of type 2 diabetes mellitus (T2D) is increasing in youth, yet little is known about the underlying pathophysiology. Decreased insulin suppression of lipolysis and elevated non-esterified free fatty acid (NEFA) concentrations are known to be associated with insulin resistance and T2D in adults, but less is known about the relationship in adolescents.

Objectives: This study aimed to assess adipose tissue insulin resistance (IR; insulin suppression of lipolysis) and its metabolic correlates in lean, obese and T2D adolescents.

Methods: Forty-seven lean, obese and T2D youth underwent hyperinsulinaemic (80 mU*m(-2) *min(-1)) euglycaemic clamps. NEFAs were measured at baseline and during steady state. Insulin-mediated suppression of lipolysis (%NEFA suppression from baseline) was calculated, and metabolic risk factors were assessed by %NEFA suppression tertile.

Results: There was expected variability in %NEFA suppression within obese and T2D youth, but a subset had significantly reduced suppression of lipolysis. NEFA suppression tertile was significantly inversely associated with fasting triglycerides (P = 0.0001), log alanine aminotransferase (ALT; P = 0.02) and low-density lipoprotein cholesterol (P = 0.0002).

Conclusions: Marked adipose tissue IR occurs in some obese and T2D adolescents, which may result in release of triglycerides into the circulation and liver deposition of fatty acids, as evidenced by higher ALT in poor NEFA suppressors.

Keywords: Adipose tissue insulin resistance; adolescents; free fatty acids; type 2 diabetes.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipose Tissue / metabolism*
  • Adolescent
  • Adolescent Health Services
  • Blood Glucose / metabolism
  • Body Mass Index
  • Diabetes Mellitus, Type 2 / metabolism*
  • Fatty Acids, Nonesterified / metabolism
  • Female
  • Glucose Clamp Technique
  • Humans
  • Insulin Resistance*
  • Lipolysis
  • Male
  • Obesity / metabolism*
  • Thinness / metabolism*
  • Triglycerides / metabolism

Substances

  • Blood Glucose
  • Fatty Acids, Nonesterified
  • Triglycerides