Tuesday, September 10, 2013

Fatty liver disease is rising fast in the children

Fatty Liver disease once thought to afflict primarily adult alcoholics appears to be rampant in children. Some 1 in 10 children in the U.S., or more than 7 million, are thought to have the disease, according to recent studies.

The condition, in which the liver becomes bloated and discolored by yellowish fat cells, has become so common in non-drinkers that it has been dubbed nonalcoholic fatty liver disease.

The disease’s prevalence is alarming doctors who worry about its progression to nonalcoholic steatohepatitis, or NASH, when the fatty liver becomes inflamed and cells are damaged. That leads to the end stage of cirrhosis, when the liver forms scar tissue and ultimately stops working.

The condition’s rise is tied to the obesity epidemic—about 40% of obese children have it—but isn’t caused solely by being overweight. The disease appears to be growing among normal-weight children too, experts say.

And even though obesity rates are starting to level off, the prevalence of fatty liver disease continues to rise, they say.

It also has no symptoms, which means a person could have it for decades without knowing. The disease is very silent.

Because fatty liver disease has been recognized only fairly recently in children, it’s unclear how the disease progresses into adulthood. Roughly 10% of people with fatty liver disease will develop NASH; another 15% to 20% of those might get cirrhosis. While the early stages of fatty liver disease and NASH are reversible, cirrhosis is very difficult and sometimes it cannot be reversed.

In a study published this year, the percentage of children in the sample suspected of having the disease grew to 10.7% between 2007 and 2010, from about 4% between 1988 and 1994.

In the last decade, more scientists have started studying fatty liver disease and NASH, trying to figure out who gets them and why.

NASH, the inflamed fatty liver condition, is currently the third-most-common reason for liver transplants, behind alcoholism and hepatitis C. Experts expect it will eclipse the other two by 2030. The liver helps digest food, absorb nutrients and expel toxins from the body.

It’s likely there are multiple factors that worsen fatty liver disease. Early research shows that the disease is partly genetic but likely needs to be triggered by environmental conditions, like obesity or insulin resistance. Much of the current research has focused on genes and specific nutrients in the diet that might cause the disease. One culprit is fructose, a type of sugar found in corn syrup and fruit juice, which are widely consumed in western diets.

Some imaging studies of children born from obese women show that even the infants have more fat on their liver.

Also, certain ethnic groups, including Mexican-Americans, appear to be particularly susceptible, whereas African-Americans appear more protected against fatty liver disease. Scientists have discovered several genes linked to the disease. At least one, PNPLA3, appears more often in the Mexican-American population.

Usually fatty liver disease is detected when other health problems arise. Obesity, insulin resistance or diabetes may prompt a doctor to order blood work to determine how the liver is functioning.

There’s a debate in the field about whether kids should be routinely screened for the condition and, if so, the best way to do it. While elevated liver enzymes can be a sign of the disease, hepatitis C and other metabolic liver diseases must be ruled out first. Ultrasound helps detect the presence of fat on the liver, but is expensive. The best way of diagnosing a fatty liver is to take a sample of the liver with a biopsy, but this procedure can be painful and has side effects.

Researchers are trying to identify biomarkers detectable through breath or blood samples instead. At a major conference in the field called Digestive Disease Week,  a pilot study was presented. It showed that different concentrations of chemicals were found in the breath of obese kids with fatty liver disease compared with those without. If the test is validated upon further study, it may be useful clinically in the future.

Treatments for fatty liver disease are limited. They include weight loss through diet and exercise. Another way to battle the condition is through alternative medicine.


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