Diabetics can control fatty liver with exercise

By Megan Rauscher

NEW YORK (Reuters Health) - Regular exercise not only helps overweight type 2 diabetics lose weight and become more physically fit, it also trims harmful fat stores from in and around the liver, a new study suggests.

"We've uncovered a hidden benefit of exercise. It reduces fat in the liver -- the fat that you don't see, but that can kill you," study leader Dr. Kerry Stewart, an exercise physiologist at Johns Hopkins in Baltimore, told Reuters Health.

He reported the study findings today at the annual meeting of the American Association of Cardiovascular and Pulmonary Rehabilitation in Indianapolis.

Overweight or obese people with type 2 diabetes often have fatty livers, which not only increases the risk of liver cirrhosis, liver failure and cancer, but also disrupts metabolism, fuels inflammation in the body, and can lead to high lipid levels, which can harm the heart.

Stewart's team randomly assigned 77 adults with type 2 diabetes to supervised exercise or no exercise for 6 months. The exercisers rode a bicycle, ran on a treadmill or walked briskly for 45 minutes 3 times a week. They also lifted free weights for about 20 minutes thrice weekly. The control group was asked to avoid any formal aerobic fitness or gym classes.

As expected, "we also saw big improvements in physical fitness and reductions in body fat in the exercisers," Stewart told Reuters Health.

Liver imaging studies performed at the beginning and end of the study showed much lower levels of liver fat in the exercising group, while levels remained the same in the non-exercising group. "The exercisers had 40 percent less fat in their livers," Stewart said.

"The thing about liver fat," Stewart added "is that a lot of people have it and when you think about the benefits of exercise, liver fat isn't on the radar screen and we know that it's a big problem."

"People with type 2 diabetes have added reason to be active and to exercise, not just because it is good for their overall health, but also because our study results pinpoint a key benefit to trimming the fatty liver that complicates their illness and which could accelerate heart disease and liver failure," Stewart said.