MRI Shows Improved Heart Function after Low-Calorie Diet

CHICAGO - Cardiac MRI scans showed a low-calorie diet eliminates insulin dependence and improves heart health in obese patients with diabetes, according to a study presented Monday at RSNA 2011. 

"It is striking to see how a relatively simple intervention of a very low calorie diet effectively cures type 2 diabetes mellitus. Moreover, these effects are long term, illustrating the potential of this method,” said the study’s lead author, Sebastian Hammer, MD, PhD from the Department of Radiology at Leiden University Medical Center in the Netherlands.

Diabetes affects 25.8 million people in the U.S., according to the Centers for Disease Control and Prevention. Type 2 diabetes represents about 95 percent of diagnosed cases among adults and can lead to organ damage.

Using cardiac MRI, researchers looked at cardiac function, fat around the heart and body mass index (BMI) in 15 patients - seven men and eight women - with type 2 diabetes before and four months after the diet.

Patients were put on the Modifast meal replacement diet for four months. The 500 daily calorie diet jumpstarts weight loss though powders that contain all of your essential daily nutrients. Hammer said losing weight is difficult when you’re insulin dependent.

From the first day of the diet, not a single patient needed insulin - a huge motivator to stay with the diet.

“All patients who started the study, finished the study,” Hammer said.

Pericardial fat is fat surrounding the heart. As plaque builds up around the coronary arteries it can hurt cardiac function. Hammer looked at the long-term impact of weight loss induced by calorie restriction on pericardial fat and cardiac function.

Pericardial fat decreased from 39 ml to 31 ml and diastolic heart function improved. Although subjects regained some weight after 18 months, pericardial fat stayed down, increasing to just 32 ml.

"Our results show that 16 weeks of caloric restriction improved heart function in these patients," Hammer said. "More importantly, despite regain of weight, these beneficial cardiovascular effects were persistent over the long term."

BMI also dropped from about 35 to 28 after four months and back up to 31 after 18 months.

Hammer said this study highlights the importance of imaging in these kinds of treatments. Imaging equipment is available and easy to use in community hospitals.

"MRI clearly showed all the changes in fat compartments, structural changes in the heart and improvements in diastolic function, making it a very effective method of quantifying the effects of metabolic interventions," he says.

The extreme low-calorie diet is not intended to be a permanent lifestyle choice and does not work for all patients. A combination of medicine, exercise and diet are standard methods for treating obese patients with diabetes.

"It is of utmost importance to follow such a complicated intervention under strict medical supervision,” Hammer said, "especially as patients may be able to stop all anti-diabetic therapy from day one."

The study’s patients had no history of cardiac complaints. Hammer said they will study individuals with diabetes who also have cardiac complaints to see if the diet would be safe and effective for them.