Influence of gender, race, and ethnicity on suspected fatty liver in obese adolescents.
OBJECTIVE
Fatty liver is a common cause of liver disease in children. However, the epidemiology of pediatric fatty liver is limited to single-center case series of nonalcoholic fatty liver disease (NAFLD). Obesity and insulin resistance are major established risk factors for NAFLD. The role of gender, race, and ethnicity on the prevalence of fatty liver in obese children is unknown.


METHODS
We recruited obese 12th-grade participants from the Child and Adolescent Trial for Cardiovascular Health in California, Louisiana, Minnesota, and Texas. Serum samples were collected at school when the participants were well. Alanine aminotransferase (ALT) was measured by kinetic enzymatic assay, and ALT >40 U/L was defined as abnormal. Causes of abnormal ALT other than NAFLD were excluded by serum testing.


RESULTS
A total of 127 obese students (73 female, 54 male) had a mean BMI of 35.2 kg/m2. Unexplained ALT elevation was present in 23% of participants overall. The mean ALT for participants with normal values was 28 U/L and for participants with an abnormal ALT was 56 U/L. Abnormal ALT was significantly more prevalent in boys (44%) than in girls (7%). The prevalence of abnormal ALT differed significantly by race and ethnicity (Hispanic: 36%; white: 22%; black: 14%). Serum ALT value was significantly predicted by the combination of gender, race/ethnicity, and BMI. After controlling for gender and BMI, Hispanic ethnicity significantly predicted greater ALT than black race.


CONCLUSIONS
In a national, school-based sample of obese adolescents, boys were 6 times more likely than girls to have an unexplained elevated ALT. Given that participants were well and causes of chronic liver disease were excluded, we speculate that obese adolescent boys have an increased prevalence of fatty liver compared with obese adolescent girls. This population-based study also supports the hypothesis that NAFLD is more common in Hispanic adolescents. These findings have implications for both disease screening and studies of fatty liver pathophysiology.
Schwimmer
Jeffrey B
JB
Division of Gastroenterology, Hepatology, and Nutrition, University of California, 200 W Arbor Dr, San Diego, CA 92103-8450, USA. jschwimmer@ucsd.edu
McGreal
Nancy
N
Deutsch
Reena
R
Finegold
Milton J
MJ
Lavine
Joel E
JE
D000293:Adolescent; D000410:Alanine Transaminase; D044383:Black People; D015992:Body Mass Index; D005234:Fatty Liver / Q000097:blood / Q000208:ethnology / Q000209:etiology*; D005260:Female; D005500:Follow-Up Studies; D006630:Hispanic or Latino; D006801:Humans; D008297:Male; D009765:Obesity / Q000097:blood / Q000150:complications* / Q000208:ethnology; D015995:Prevalence; D016032:Randomized Controlled Trials as Topic; D012737:Sex Factors; D012959:Socioeconomic Factors
D000410:Alanine Transaminase