"The factors driving obesity don't live within the confines of the hospital," says Shikha Sundaram, MD, pediatric hepatologist at Children's Hospital Colorado. "They live in the confines of the worlds in which each patient lives. Unfortunately, by the time we see them, their obesity-related, non-alcoholic fatty liver disease (NAFLD) may be fairly progressed."
According to the Centers for Disease Control and Prevention, approximately 15% of U.S. children are obese; 30% of those kids have NAFLD, which may lead to swelling, inflammation, cirrhosis, cancer or liver failure. NAFLD has become the number one reason for referral to the Pediatric Liver Center at Children's Colorado, and, according to Dr. Sundaram, is likely to surpass viral hepatitis as the number one reason for all liver transplants in the U.S.
Treating non-alcoholic fatty liver disease
The most effective treatment for NAFLD is slow and steady weight loss and exercise, but that is not an easy treatment, Dr. Sundaram explains.
"The reality is that success in helping patients lose weight and keep it off isn't very good — that's not just Children's Colorado, that's any hospital. It's a hard thing for families to understand — why losing weight and exercise is their only proven treatment option."
Instead of surrendering to an inevitability — that more children will acquire NAFLD and might need a transplant, for which there will be fewer healthy livers — Dr. Sundaram is studying the nuances of the disease to figure out how to halt its progression.
Halting the progression with oxygen
In particular, she is investigating how nocturnal hypoxia and sleep apnea may affect the liver in patients with NAFLD. Dr. Sundaram already knew that when patients who had a liver transplant experienced low oxygen levels, it resulted in injury to their new organ; she wondered if the same thing was happening in patients with NAFLD. If it did, perhaps they could interrupt the injury’s progression with effective nighttime breathing treatments.
Sleep studies each year at Children's Colorado
So far, Dr. Sundaram and her colleagues have proven her hypothesis correct by conducting sleep studies with co-investigator Ann Halbower, MD, of the Children's Colorado Sleep Center. On children who had NAFLD (determined through liver biopsy), they found that those who experienced nocturnal hypoxia also had progression of their liver disease, especially as the hypoxia became more severe.
They are now studying if they can slow or stop the progression of NAFLD through the nighttime use of continuous positive airway pressure (CPAP) to raise oxygen levels.
"Wearing CPAP is not an easy thing for kids, but it's certainly easier than weight loss, which can be a real struggle for children," Dr. Sundaram says. "Maybe this is one way we can take away at least one of the insults to their liver."