Researchers study effects of weight loss in adolescents

A team of researchers at Washington University School of Medicine in St. Louis is studying how fatty liver disease affects sugar and fat metabolism in overweight adolescents and how losing weight affects the condition. In the last 30 years, the number of overweight children has doubled in the United States, and overweight children are at increased risk for the problem.

In fatty liver disease, fat accumulates in liver cells. A patient is diagnosed with fatty liver when there is more than 5 percent fat in the liver. In children and adolescents, fatty liver is most common in those who are overweight, but it also can occur in young people with diabetes or, less commonly, with other conditions. Those with fatty liver disease may have an enlarged liver or elevations in liver enzyme tests. Most do not have obvious symptoms, but some may complain of fatigue, malaise or vague abdominal pain that can bring them to the attention of a physician. If fatty liver goes untreated and risk factors are not controlled, a small percentage of young people may progress to liver scarring or even liver failure. Fatty liver disease is thought to affect about 20 percent of the population in the developed world, but like type 2 diabetes, it has been uncommon in young people until recently. “The prevalence of fatty liver disease is increasing in children because of the marked increase in childhood obesity,” says Samuel Klein, M.D., the Danforth Professor of Medicine and Nutritional Science, director of the Center for Human Nutrition and chief of the Division of Geriatrics and Nutritional Sciences at Washington University School of Medicine. “We are evaluating how excess fat in the liver impairs liver function and can contribute to high blood sugar and abnormal blood lipids.” Klein and colleagues are studying children between the ages of 13 and 17. Participants in the study cannot have diabetes or weigh more than 300 pounds. A history of other liver disease or excessive alcohol use also make adolescents ineligible. Study participants will receive medical screenings and imaging tests to determine fat levels in the body and fat in the liver. They also receive a detailed metabolism study to determine how their bodies process fat, protein and sugar and how insulin interacts with those substances. When baseline studies are complete, participants will begin a weight-loss program involving a reduced-calorie diet. The weight-loss program includes regular meetings with trained behaviorists and dieticians to help participants keep track of what they are eating and to identify and try to change problem behaviors and cues for overeating. Some study participants also may take a weight loss drug called Orlistat. To help young people in the study adopt a healthier lifestyle, the whole family is encouraged to become involved. Participants will remain on the diet until they lose about 10 percent of their body weight. After maintaining that weight loss for three weeks, they will return for repeat body composition tests and metabolic studies. The second round of tests allows researchers to compare fat in the body and in the liver before and after weight loss and to identify changes in the metabolism of fat, protein and sugar. “We believe losing weight will reverse if not completely normalize some of the changes we see in children with fatty liver disease,” says Sheela Deivanayagam, M.D., study investigator and a clinical fellow in the Division of Pediatric Gastroenterology and the Center for Human Nutrition. Most study volunteers will remain in the program five to six months, depending upon how long it takes them to reach their weight-loss goal. All screening tests and research-related procedures for the study are provided free of charge. Those who complete the entire study receive a combination of money and gift cards totaling $500. (Source: Washington University School of Medicine in St. Louis: April 2006.)