By Ray Cavanaugh
Ray Cavanaugh is a freelance writer from Boston, MA. His interests include history, health topics, and current events in faraway places.
They have fatty liver disease, but they aren’t alcoholic, nor are they adults. In the US alone, about seven million children – many of them obese – have non-alcoholic fatty liver disease (NAFLD).
The rate of NAFLD among US children has tripled over the last twenty to thirty years, rising from 3-4 percent to 10-11 percent, according to Dr. Naim Alkhouri, Director of the Metabolic Liver Center at the Texas Liver Institute in San Antonio.
NAFLD is caused by an excess of fat in the liver. While the liver is supposed to contain some amount of fat, if more than 5-10 percent of the liver’s weight consists of fat, then the person likely has NAFLD.
The majority of children (and adults) with NAFLD are asymptomatic. Those who are symptomatic might present with persistent fatigue, abdominal pain, skin manifestations of spider-like blood vessels, or jaundice, among other possible symptoms.
Though in many cases NAFLD doesn’t harm the person, serious problems can emerge if it develops into its more serious form: nonalcoholic steatohepatitis (NASH), a condition which consists of liver inflammation and swelling, and can progress to the scarred liver of cirrhosis and, ultimately, liver failure.
Fortunately, NAFLD can be reversed, as long as it hasn’t reached an advanced stage. Lifestyle changes, such as better nutrition and increased exercise, are currently the best-known way of mitigating and possibly reversing its effects. Fish oil, with its omega-3 fatty acids, has been mentioned as carrying potential benefit. And it’s important to avoid soft drinks with high fructose content, which have been shown to contribute to NAFLD.
Weight reduction is crucial in helping to alleviate NAFLD. However, the weight loss should be gradual, as rapid weight loss can exacerbate NAFLD (and also can trigger the condition in one who doesn’t have it). As of yet, there are no widely accepted medications for juvenile NAFLD; clinical trials are underway for medications intended to treat adult NAFLD. Vitamin E has shown some efficacy in at least one juvenile NAFLD study.
Prevalence of NAFLD appears to vary according to ethnicity, with higher rates in those of Asian and Latino descent and lower rates in those of African descent. There is also a gender disparity, with boys having considerably higher rates than girls – likely owing in part to males’ increased tendency to store fat in the abdomen.
Liver biopsy has been the standard method of diagnosing NAFLD, but hospitals more recently have been seeking less invasive methods. Among them is magnetic resonance elastography (MRE), which is used by the Mayo Clinic.
When he was previously with the Cleveland Clinic, Alkhouri helped to develop a NAFLD calculator, which involves entering the blood liver enzyme count and platelet count into a mathematical equation. The goal of this calculator is to avoid having to perform a liver biopsy, but Alkhouri advises that, for now, the calculator “needs further validation.” In order to diagnose the more advanced condition of NASH, a biopsy is needed.
Alkhouri relates how the focus of current research involves “understanding the natural history of NAFLD in children,” finding “biomarkers to replace liver biopsy,” and, of course, striving to identify effective treatment.
Specialized clinics for juvenile NAFLD are found in such locations as Phoenix Children’s Hospital, Rady Children’s Hospital in San Diego, Morgan Stanley Children’s Hospital of New York-Presbyterian in Manhattan, and the Children’s Hospital at Montefiore in the Bronx.
Though juvenile NAFLD has been on the radar of the medical community for about “15 years or so,” many pediatricians “still don’t screen routinely,” and getting them to become more proactive about screening has proven “a slow process,” says Alkhouri. In fact, most children with NAFLD are unaware of their condition because of a “lack of consistent screening practices among pediatricians.”
The statistics Alkhouri shares are troubling: some 35-50 percent of obese children have NAFLD, and 20 percent of children with NAFLD have the advanced form of NASH. Also, 10-15 percent of children with NAFLD are in a predicament that could be described as “pre-cirrhosis.”
Though most cases of juvenile NAFLD are caused by excess weight and associated insulin resistance, “up to 7% of non-overweight or obese children may have NAFLD,” according to a new study that Alkhouri and others will present at the upcoming International Liver Congress, held in Amsterdam this April.
The obesity crisis, though, is the driving force behind the surging rates of both juvenile and adult NAFLD. And, despite increasing awareness in the medical community, he sees the issue as “getting worse” in the next ten years.
The percent of children with NAFLD who will need a liver transplant down the road is “not known at this point,” but Alkhouri points out that “the histology of NAFLD is identical to alcoholic liver disease.”
Which means that, in terms of livers, obesity is the new alcoholism.