From the Journals

Pediatric NAFLD almost always stems from excess body weight, not other etiologies



Nonalcoholic fatty liver disease (NAFLD) in children is almost always caused by excess body weight, not other etiologies, based on a retrospective analysis of 900 patients.

Just 2% of children with overweight or obesity and suspected NAFLD had other causes of liver disease, and none tested positive for autoimmune hepatitis (AIH), reported lead author Toshifumi Yodoshi, MD, PhD, of Cincinnati Children’s Hospital Medical Center, and colleagues.

“Currently, recommended testing of patients with suspected NAFLD includes ruling out the following conditions: AIH, Wilson disease, hemochromatosis, alpha-1 antitrypsin [A1AT] deficiency, viral hepatitis, celiac disease, and thyroid dysfunction,” the investigators wrote in Pediatrics.

Yet evidence supporting this particular battery of tests is scant; just one previous pediatric study has estimated the prevalence of other liver diseases among children with suspected NAFLD. The study showed that the second-most common etiology, after NAFLD, was AIH, at a rate of 4%.

But “the generalizability of these findings is uncertain,” noted Dr. Yodoshi and colleagues, as the study was conducted at one tertiary center in the western United States, among a population that was predominantly Hispanic.

This uncertainty spurred the present study, which was conducted at two pediatric centers: Cincinnati Children’s Hospital Medical Center (2009-2017) and Yale New Haven (Conn.) Children’s Hospital (2012-2017).

The final analysis involved 900 patients aged 18 years or younger with suspected NAFLD based on hepatic steatosis detected via imaging and/or elevated serum aminotransferases. Demographically, a slight majority of the patients were boys (63%), and approximately one-quarter (26%) were Hispanic. Median BMI z score was 2.45, with three out of four patients (76%) exhibiting severe obesity. Out of 900 patients, 358 (40%) underwent liver biopsy, among whom 46% had confirmed nonalcoholic steatohepatitis.

All patients underwent testing to exclude the aforementioned conditions using various diagnostics, revealing that just 2% of the population had etiologies other than NAFLD. Specifically, 11 children had thyroid dysfunction (1.2%), 3 had celiac disease (0.4%), 3 had A1AT deficiency (0.4%), 1 had hemophagocytic lymphohistiocytosis, and 1 had Hodgkin’s lymphoma. None of the children had Wilson disease, hepatitis B or C, or AIH.

Dr. Yodoshi and colleagues highlighted the latter finding, noting that 13% of the patients had autoantibodies for AIH, but “none met composite criteria.” This contrasts with the previous study from 2013, which found an AIH rate of 4%.

“Nonetheless,” the investigators went on, “NAFLD remains a diagnosis of exclusion, and key conditions that require specific treatments must be ruled out in the workup of patients with suspected NAFLD. In the future, the cost-effectiveness of this approach will need to be investigated.”

Dr. Francis Rushton

Dr. Francis Rushton

Interpreting the findings, Francis E. Rushton, MD, of Beaufort (S.C.) Memorial Hospital emphasized the implications for preventive and interventional health care.

“This study showing an absence of etiologies other than obesity in overweight children with NAFLD provides further impetus for pediatricians to work on both preventive and treatment regimens for weight issues,” Dr. Rushton said. “Linking community-based initiatives focused on adequate nutritional support with pediatric clinical support services is critical in solving issues related to overweight in children. Tracking BMI over time and developing healthy habit goals for patients are key parts of clinical interventions.”

The study was funded by the National Institutes of Health. The investigators reported no conflicts of interest.

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