title: Ethnic differences in pancreatic fat accumulation and its relationship with other fat depots and inflammatory markers.
abstract: OBJECTIVE
  Visceral adipose tissue (VAT) and hepatic fat are associated with insulin resistance and vary by sex and ethnicity. Recently, pancreatic fat fraction (PFF) has also been linked with increasing obesity. Our aim was to assess ethnic and sex differences in PFF and its relationship to other fat depots, circulating free fatty acids (FFA), insulin secretion and sensitivity, and inflammation in obese adolescents and young adults.
  
  
  METHODS
  We examined 138 (40 males, 98 females) obese Hispanics and African Americans (13-25 years). Subcutaneous adipose tissue and VAT volumes, hepatic fat fraction (HFF), and PFF were determined by magnetic resonance imaging. Insulin sensitivity and β-cell function were assessed during an intravenous glucose tolerance test.
  
  
  RESULTS
  Hispanics had higher PFF than African Americans (7.3 ± 3.8 vs. 6.2 ± 2.6%, P = 0.03); this ethnic difference was higher in young adults compared with children and adolescents (ethnicity × age: P = 0.01). Males had higher PFF than females (P < 0.0001). PFF was positively correlated with VAT (r = 0.45, P < 0.0001), HFF (r = 0.29, P < 0.0001), and FFA (r = 0.32, P = 0.001). PFF positively correlated with inflammatory markers but lost significance when adjusted for VAT. In multiple stepwise regression analysis, VAT and FFA were the best predictors of PFF (adjusted R(2) = 0.40). There were no significant correlations between PFF and markers of insulin sensitivity or β-cell function.
  
  
  CONCLUSIONS
  PFF is higher in Hispanics than African Americans, and this difference increases with age. In young obese individuals, PFF is related to VAT, HFF, and circulating FFA, thus possibly contributing to their increased risk for type 2 diabetes and related metabolic disorders.
authors.affiliation: Department of Preventive Medicine, Childhood Obesity Research Center, University of Southern California, Los Angeles, California, USA.
authors.forename: Kim-Anne
authors.initials: KA
authors.lastname: Lê
authors.forename: Emily E
authors.initials: EE
authors.lastname: Ventura
authors.forename: Jessica Q
authors.initials: JQ
authors.lastname: Fisher
authors.forename: Jaimie N
authors.initials: JN
authors.lastname: Davis
authors.forename: Marc J
authors.initials: MJ
authors.lastname: Weigensberg
authors.forename: Mark
authors.initials: M
authors.lastname: Punyanitya
authors.forename: Houchun H
authors.initials: HH
authors.lastname: Hu
authors.forename: Krishna S
authors.initials: KS
authors.lastname: Nayak
authors.forename: Michael I
authors.initials: MI
authors.lastname: Goran
mesh_terms: D000293:Adolescent; D000328:Adult; D001741:Black or African American / Q000706:statistics & numerical data*; D017677:Age Distribution; D015415:Biomarkers / Q000097:blood; D004038:Diet, Reducing; D015444:Exercise; D005260:Female; D005951:Glucose Tolerance Test; D006630:Hispanic or Latino / Q000706:statistics & numerical data*; D006801:Humans; D007333:Insulin Resistance; D050417:Insulin-Secreting Cells / Q000378:metabolism; D050152:Intra-Abdominal Fat / Q000378:metabolism / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D009765:Obesity / Q000208:ethnology / Q000378:metabolism / Q000628:therapy; D010179:Pancreas / Q000378:metabolism / Q000473:pathology*; D011237:Predictive Value of Tests; D012307:Risk Factors; D017678:Sex Distribution; D050151:Subcutaneous Fat / Q000378:metabolism / Q000473:pathology; D055815:Young Adult
chemical_list: D015415:Biomarkers