Ectopic Fat Deposition in Prediabetic Overweight and Obese Minority Adolescents

• Published in: The journal of clinical endocrinology and metabolism Vol. 98; no. 3; pp. 1115 - 1121
• Main Authors: Toledo-Corral, Claudia M, Alderete, Tanya L, Hu, Houchun H, Nayak, Krishna, Esplana, Sherryl, Liu, Ting, Goran, Michael I, Weigensberg, Marc J
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Endocrine Society 01-03-2013; Copyright by The Endocrine Society
• Subjects: Adolescent; African Americans - statistics & numerical data; Biological and medical sciences; Cross-Sectional Studies; Diabetes Mellitus, Type 2 - ethnology; Diabetes Mellitus, Type 2 - metabolism; Diabetes Mellitus, Type 2 - pathology; Endocrine Care; Endocrinopathies; Feeding. Feeding behavior; Female; Fundamental and applied biological sciences. Psychology; Hispanic Americans - statistics & numerical data; Humans; Insulin Resistance - physiology; Intra-Abdominal Fat - metabolism; Intra-Abdominal Fat - pathology; Liver - pathology; Magnetic Resonance Imaging; Male; Medical sciences; Obesity - ethnology; Obesity - metabolism; Obesity - pathology; Overweight - ethnology; Overweight - metabolism; Overweight - pathology; Pancreas - pathology; Prediabetic State - ethnology; Prediabetic State - metabolism; Prediabetic State - pathology; Risk Factors; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Vertebrates: endocrinology; Human; Obesity; Nutrition; Body weight; Nutrition disorder; Metabolic diseases; Corporal biometry; Overweight; Minority; Adolescent; Fat; Ectopia; Deposition; Endocrinology; Nutritional status
• ISSN: 0021-972X; 1945-7197
• DOI: 10.1210/jc.2012-3806

Context:
Optimizing effective prevention and treatment of type 2 diabetes in youth is limited by incomplete understanding of its pathophysiology and how this varies across ethnicities with high risk.
Objective:
The aim of this study was to examine the contribution of visceral adipose tissue (VAT), hepatic fat fraction (HFF), and pancreatic fat fraction (PFF) to prediabetes in overweight/obese African American (AA) and Latino youth.
Design and Setting:
We conducted a cross-sectional study in an academic pediatric care facility.
Subjects:
A total of 148 healthy, overweight/obese adolescents (56 AA, 92 Latino; 72 males, 76 females; age, 15.5 ± 1.2 y; BMI z-score, 2.1 ± 0.5) participated in the study. They were normal glucose tolerant (n = 106) and prediabetic (n = 42), based on fasting glucose of 100–125 mg/dL and/or 2-hour glucose of 140–199 mg/dL, and/or hemoglobin A1C 6.0–6.4%.
Main Outcome Measures:
We measured sc abdominal adipose tissue, VAT, HFF, and PFF by 3-Tesla magnetic resonance imaging and measured total body fat by dual-energy x-ray absorptiometry.
Results:
Adolescents with prediabetes had 30% higher HFF (P = .001) and 31% higher PFF (P = .042), compared to those with normal glucose tolerance after controlling for age, sex, pubertal stage, ethnicity, total percentage body fat, and VAT. Logistic regression showed that PFF predicted prediabetes in AAs and HFF predicted prediabetes in Latinos, with the odds of having prediabetes increased by 66% for every 1% increase in PFF in African Americans, and increased by 22% for every 1% increase in HFF in Latinos.
Conclusion:
These data demonstrate that ectopic fat phenotypes associated with prediabetes are established by adolescence. Ethnic differences in the deposition of ectopic fat in adolescents with prediabetes may differ, with pancreatic fat in AAs, vs hepatic fat in Latino adolescents, being associated with diabetes risk.