Researchers Investigate Obesity-related Disease

The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) is supporting a 5-year study of nonalcoholic steatohepatitis (NASH) in hopes of finding prevention and treatment approaches to this recently identified condition. NASH is a liver disease that occurs most often in adults over the age of 40 who are overweight or have diabetes, insulin resistance, or hyperlipidemia (excess amounts of fatty substances in the blood). It resembles alcoholic liver disease, but people with NASH drink little or no alcohol.

NASH, which may result in an enlarged liver but is often without symptoms, is diagnosed by means of a liver biopsy to detect accumulation of fat in the liver (steatosis), inflammation, cell injury, and fibrosis (hepatitis). While some people with fatty liver suffer no ill effects, others develop cirrhosis and end-stage liver disease.

Scientists are uncertain what causes NASH, but believe it’s a combination of insulin resistance and oxidative stress (cell damage caused by free radical molecules). Although most people with NASH are middle-aged, obese, and diabetic, the disease also strikes children and normal-weight adults without diabetes.

“It’s definitely a recognized problem,” says Patricia Robuck, Ph.D., M.P.H., Director of Clinical Trials at NIDDK’s Division of Digestive Diseases and Nutrition. “But there is no systematic way to characterize the stage of the disease or have a firm definition of it. We don’t know the natural history—who will get worse and who won’t. We don’t know the optimal therapy.”

NIDDK plans to establish a NASH Clinical Research Network, made up of seven clinical centers and a data-coordinating center, to study this poorly understood disease. Researchers will investigate NASH’s origin, contributing factors, natural history, and complications. Their first priority will be to develop common definitions and terms for the clinical diagnosis and staging of NASH. Ultimately, researchers hope to identify safe and effective methods to prevent and treat this increasingly common disease.

For more information about the NASH Clinical Research Network, visit http://grants.nih.gov/grants/guide/rfa-files/RFA-DK-01-025.html. s