Yield of diagnostic tests in obese children with an elevated alanine aminotransferase.
OBJECTIVE
Nonalcoholic fatty liver disease (NAFLD) is associated with obesity and affects roughly 10% of children. However, NAFLD is often diagnosed by exclusion - that is, obese children with an elevated alanine aminotransferase (ALT) are screened for other liver diseases in the absence of a biopsy. This testing is nonstandardized, and professional society recommendations differ. This study examines the yield of testing for disorders other than NAFLD in this patient population.


METHODS
A retrospective study was performed in 120 obese, asymptomatic, noncholestatic children with an ALT ≥40 U/L and additional diagnostic testing.


RESULTS
No patients were found to have Wilson's, hepatitis A, hepatitis B, hepatitis C, cytomegalovirus, alpha-1 antitrypsin deficiency, autoimmune hepatitis, celiac disease or Epstein-Barr virus. Only one patient (1/120) was identified with definite disease other than NAFLD, which was muscular dystrophy. The positive predictive value of a screening test was 5%, and the specificity was 97%. Of 70 children with an abdominal ultrasound, no significant abnormalities were identified.


CONCLUSIONS
Extensive testing in asymptomatic, noncholestatic, obese children with an elevated ALT may be of limited diagnostic value and false-positive tests are likely. Large, prospective studies are needed to help focus the work up in this patient population.
Division of Pediatric Gastroenterology and Nutrition, Children's Hospital at Montefiore, Albert Einstein College of Medicine, Bronx, NY, USA.
Bryan
B
Rudolph
Division of Pediatric Gastroenterology and Nutrition, Children's Hospital at Montefiore, Albert Einstein College of Medicine, Bronx, NY, USA.
Yolanda
Y
Rivas
Division of Pediatrics, Children's Hospital at Montefiore, Albert Einstein College of Medicine, Bronx, NY, USA.
Shulamit
S
Kulak
Division of Pediatric Gastroenterology and Nutrition, Children's Hospital at Montefiore, Albert Einstein College of Medicine, Bronx, NY, USA.
Debra
D
Pan
Division of Pathology, Children's Hospital at Montefiore, Albert Einstein College of Medicine, Bronx, NY, USA.
Michelle
M
Ewart
Division of Radiology, Children's Hospital at Montefiore, Albert Einstein College of Medicine, Bronx, NY, USA.
Terry L
TL
Levin
Division of Pediatric Gastroenterology and Nutrition, Children's Hospital at Montefiore, Albert Einstein College of Medicine, Bronx, NY, USA.
John F
JF
Thompson
Division of Pediatrics, Children's Hospital at Montefiore, Albert Einstein College of Medicine, Bronx, NY, USA.
Kathryn
K
Scharbach
D000293:Adolescent; D000410:Alanine Transaminase / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008107:Liver Diseases / Q000097:blood / Q000175:diagnosis* / Q000209:etiology; D008297:Male; D009765:Obesity / Q000097:blood / Q000150:complications*; D012189:Retrospective Studies
D000410:Alanine Transaminase
Alanine Transaminase; Mass Screening; Nonalcoholic Fatty Liver Disease; Obesity