title: Predicting hepatic steatosis in a racially and ethnically diverse cohort of adolescent girls.
abstract: OBJECTIVE
  To develop a risk assessment model for early detection of hepatic steatosis using common anthropometric and metabolic markers.
  
  
  METHODS
  This was a cross-sectional study of 134 adolescent and young adult females, age 11-22 years (mean 13.3±2 years) from a middle school and clinics in Madison, Wisconsin. The ethnic distribution was 27% Hispanic and 73% non-Hispanic; the racial distribution was 64% Caucasian, 31% African-American, and 5% Asian, Fasting glucose, fasting insulin, alanine aminotransferase (ALT), body mass index (BMI), waist circumference (WC), and other metabolic markers were assessed. Hepatic fat was quantified using magnetic resonance imaging proton density fat fraction (MR-PDFF). Hepatic steatosis was defined as MR-PDFF>5.5%. Outcome measures were sensitivity, specificity, and positive predictive value (PPV) of BMI, WC, ALT, fasting insulin, and ethnicity as predictors of hepatic steatosis, individually and combined, in a risk assessment model. Classification and regression tree methodology was used to construct a decision tree for predicting hepatic steatosis.
  
  
  RESULTS
  MR-PDFF revealed hepatic steatosis in 16% of subjects (27% overweight, 3% nonoverweight). Hispanic ethnicity conferred an OR of 4.26 (95% CI, 1.65-11.04; P=.003) for hepatic steatosis. BMI and ALT did not independently predict hepatic steatosis. A BMI>85% combined with ALT>65 U/L had 9% sensitivity, 100% specificity, and 100% PPV. Lowering the ALT value to 24 U/L increased the sensitivity to 68%, but reduced the PPV to 47%. A risk assessment model incorporating fasting insulin, total cholesterol, WC, and ethnicity increased sensitivity to 64%, specificity to 99% and PPV to 93%.
  
  
  CONCLUSIONS
  A risk assessment model can increase specificity, sensitivity, and PPV for identifying the risk of hepatic steatosis and guide the efficient use of biopsy or imaging for early detection and intervention.
authors.affiliation: Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI. Electronic address: jrehm@pediatrics.wisc.edu.
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Rehm
authors.affiliation: Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI.
authors.forename: Ellen L
authors.initials: EL
authors.lastname: Connor
authors.affiliation: Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI.
authors.forename: Peter M
authors.initials: PM
authors.lastname: Wolfgram
authors.affiliation: Departments of Biostatistics and Medical Informatics, University of Wisconsin School of Medicine and Public Health, Madison, WI.
authors.forename: Jens C
authors.initials: JC
authors.lastname: Eickhoff
authors.affiliation: Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, WI; Department of Medical Physics, Biomedical Engineering, Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI.
authors.forename: Scott B
authors.initials: SB
authors.lastname: Reeder
authors.affiliation: Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI.
authors.forename: David B
authors.initials: DB
authors.lastname: Allen
mesh_terms: D000293:Adolescent; D001741:Black or African American / Q000208:ethnology*; D000886:Anthropometry; D001213:Asian / Q000208:ethnology*; D015992:Body Mass Index; D002648:Child; D003430:Cross-Sectional Studies; D005234:Fatty Liver / Q000175:diagnosis* / Q000208:ethnology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D009765:Obesity / Q000208:ethnology; D050177:Overweight / Q000208:ethnology; D011237:Predictive Value of Tests; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D044465:White People / Q000208:ethnology*; D014922:Wisconsin; D055815:Young Adult