The incidence of type 2 diabetes in adolescents is increasing, and this increase is disproportionate in Hispanics and African Americans. In addition, the rise in minority obesity in youth is associated with progressive insulin resistance and risk factors for cardiovascular disease. Although the exact cause for these trends are not known, it is clear that they are closely related to the increase in obesity prevalence. However, it is not currently known why some obese subjects remain healthy and at low associated disease risk, while others appear at high disease risk and some develop type 2 diabetes. Two predominant paradigms, both based on an abnormal accumulation of body fat, have been used to explain the reasons why some obese subjects develop insulin resistance, diabetes, and cardiovascular risk, while others do not. Project 2 will examine these possible theories. The first possibility is the portal/visceral hypothesis, which suggests an abnormal accumulation of visceral adipose tissue. The second possibility is the ectopic fat storage hypothesis, which suggests an abnormal accumulation of ectopic fat in liver, skeletal muscle and possibly the pancreas. In Project 2, we will measure intraabdominal, hepatic, pancreatic and muscular fat accumulation, and characterize intramuscular lipid composition in Hispanic, African American and Caucasian adolescents who are either lean, obese with normal glucose tolerance, obese with impaired glucose tolerance (IGT), or patients with type 2 diabetes. Regional fat deposition and composition will be assessed using state-of-the-art magnetic resonance imaging and spectroscopy. We will also employ high-resolution ultrasound to measure carotid intima-medial thickness as a surrogate for vascular fat deposition and for the risk of cardiovascular disease in these populations. Our hypotheses are: 1) Fat deposition (intraabdominal, hepatic, pancreatic and muscular fat), intramuscular levels of saturated fatty acids, and measures of carotid wall thickness will increase with degree of disease progression (lean -? obese ->pre-diabetes (obese+IGT) ? diabetes);2) At each degree of disease progression, fat deposition, the ratio of saturated-to-unsaturated fatty acid, and carotid wall thickness will be higher in Hispanic and African American subjects when compared with Caucasian subjects, even after adjusting for total body fat;and, 3) Measures of fat deposition and composition at the various sites will allow the identification of unique fat phenotypes related to differences in disease risk between Hispanic, African American and Caucasian populations. In summary, Project 2 will utilize an array of advanced imaging techniques to conduct a comprehensive analysis of the patterns of body fat deposition across the spectrum of obesity-related disease progression in minority youth.

National Institute of Health (NIH)
National Institute on Minority Health and Health Disparities (NIMHD)
Comprehensive Center (P60)
Project #
Application #
Study Section
Special Emphasis Panel (ZMD1)
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
University of Southern California
Los Angeles
United States
Zip Code
Toledo-Corral, C M; Alderete, T L; Habre, R et al. (2018) Effects of air pollution exposure on glucose metabolism in Los Angeles minority children. Pediatr Obes 13:54-62
Alderete, Tanya L; Habre, Rima; Toledo-Corral, Claudia M et al. (2017) Longitudinal Associations Between Ambient Air Pollution With Insulin Sensitivity, ?-Cell Function, and Adiposity in Los Angeles Latino Children. Diabetes 66:1789-1796
Joshi, Anand A; Vaidya, Soniya S; St-Pierre, Marie V et al. (2016) Placental ABC Transporters: Biological Impact and Pharmaceutical Significance. Pharm Res 33:2847-2878
Shearrer, G E; Daniels, M J; Toledo-Corral, C M et al. (2016) Associations among sugar sweetened beverage intake, visceral fat, and cortisol awakening response in minority youth. Physiol Behav 167:188-193
Shearrer, Grace E; O'Reilly, Gillian A; Belcher, Britini R et al. (2016) The impact of sugar sweetened beverage intake on hunger and satiety in minority adolescents. Appetite 97:43-8
Toledo-Corral, Claudia M; Alderete, Tanya L; Richey, Joyce et al. (2015) Fasting, post-OGTT challenge, and nocturnal free fatty acids in prediabetic versus normal glucose tolerant overweight and obese Latino adolescents. Acta Diabetol 52:277-84
O'Reilly, Gillian A; Belcher, Britni R; Davis, Jaimie N et al. (2015) Effects of high-sugar and high-fiber meals on physical activity behaviors in Latino and African American adolescents. Obesity (Silver Spring) 23:1886-94
Spruijt-Metz, D; Wen, C K F; O'Reilly, G et al. (2015) Innovations in the Use of Interactive Technology to Support Weight Management. Curr Obes Rep 4:510-9
Hsieh, Stephanie; Klassen, Ann C; Curriero, Frank C et al. (2015) Built Environment Associations with Adiposity Parameters among Overweight and Obese Hispanic Youth. Prev Med Rep 2:406-412
Adam, T C; Tsao, S; Page, K A et al. (2015) Insulin sensitivity and brain reward activation in overweight Hispanic girls: a pilot study. Pediatr Obes 10:30-6

Showing the most recent 10 out of 37 publications