Metformin works by cutting hunger, increasing satiety.

SAN FRANCISCO -- Metformin appears to exert its weight-loss effects in obese children by reducing their desire to eat and thus decreasing their food intake.

A substudy of a government-sponsored placebo-controlled trial found that children taking metformin not only ate less, they reported higher satiety and lower hunger than those taking placebo, Rachael Sorg said in a poster session at the annual meeting of the Endocrine Society.

The 6-month study, sponsored by the National Institutes of Health, randomized 100 obese children with severe hyperinsulinemia (mean age 10 years) to either 1,000 mg metformin twice a day or to placebo. Some of the children (45 metformin-treated and 39 placebo-treated) participated in both a pre- and posttreatment meal study to evaluate the drug's effect on food intake. One study was conducted before the drug trial commenced, and one at the end of the 6-month treatment period.

Each meal study included two buffet lunches, each containing 28 items (9,835 calories total). The first lunch was consumed after children fasted through the night. The second was consumed after they drank a 790-calorie nutrient shake for breakfast.

Subjects completed a scale of hunger, fullness, and desire to eat before after each test meal, and also kept a food diary of everything they consumed for 7 days be fore and after the test.

Compared with baseline measurements obtained in the pre--metformin meal study, children taking metformin consumed significantly fewer calories in the meal after the breakfast shake. They also reported significantly decreased feelings of hunger and increased feelings of fullness after the shake.

They reported lower hunger after the postshake meal, lower desire to eat the postshake meal, and lower caloric intake at the postfast meal as well, although none of these differences were significant.

"These data suggest that one of the mechanisms whereby metformin treatment reduces body weight in overweight, hyperinsulinemic children is by decreasing food intake and perceived hunger," said Ms. Sorg, a research assistant at the National Institutes of Child Health and Human Development.

BY MICHELE G. SULLIVAN

Mid-Atlantic Bureau