Obesity and the Metabolic Syndrome in Children and Adolescents

to the editor:
Weiss et al. (June 3 issue)[1] report the prevalence of the metabolic syndrome in children
and adolescents on the basis of their findings with the use of specific markers. Hepatic manifestations of the metabolic syndrome include nonalcoholic fatty liver disease and nonalcoholic steatohepatitis.[2,3] A valuable biomarker for both of these disorders is an elevated alanine aminotransferase level. [4] We conducted a study involving 37 overweight children (body-mass index [BMI] z score, 1.5 to 2.0) and 145 obese children (BMI z score, greater than 2.0) who were otherwise healthy to investigate the prevalence of elevated levels of liver
enzymes; the mean age of the children was 9 years (range, 1 to 12). We found a significantly elevated mean level of alanine aminotransferase, which increased as the BMI z score increased. In 48 percent of the patients, the alanine aminotransferase level was at or above the upper limit of the normal range for age. [5]Mean values for aspartate aminotransferase and
g -glutamyltransferase were normal. We therefore suspect that nonalcoholic fatty liver disease and nonalcoholic steatohepatitis are common features in obese and overweight children,
even those who are very young. Given that these two disorders are hepatic expressions of the
metabolic syndrome, we conclude that this syndrome is as common in young children as it is in
older children and adolescents.

Guido Engelmann, M.D.
Henning Lenhartz, M.D.
Jürgen Grulich-Henn, M.D.
University Children’s Hospital
69115 Heidelberg, Germany
guido_engelmann@med.uni-heidelberg.de
1. Weiss R, Dziura J, Burgert TS, et al. Obesity and the metabolic
syndrome in children and adolescents. N Engl J Med 2004;350:
2362-74.
2. Ruhl C, Everhart JE. Determinants of the association of overweight
with elevated serum alanine aminotransferase activity in the
United States. Gastroenterology 2003;124:71-9.
3. Harrison S, Di Bisceglie AM. Advances in the understanding
and treatment of nonalcoholic fatty liver disease. Drugs 2003;63:
2379-94.
4. Fishbein MH, Miner M, Mogren C, Chalekson J. The spectrum
of fatty liver in obese children and the relationship of serum aminotransferase
to severity of steatosis. J Pediatr Gastroenterol Nutr
2003;36:54-61.
5. Fischbach F, Zawta B. Age dependent reference limits of several
enzymes in plasma at different measuring temperatures. Klin Lab
1992;38:555-61.