Diet, exercise remain gold standard for diabetes

DEAR DOCTOR K: I just heard on the radio that some study says that intensive diet and exercise don't decrease heart disease risk in diabetics. Is this true? If so, I've made a lot of hard changes in my life for nothing.

DEAR READER: I assume you're referring to results from the recently publicized Look AHEAD (Action for Health in Diabetes) trial. The results of this study were reported in June of this year. Several of my patients have already asked me about it, and what I've told them is: Take these results with several grains of salt.

Here's what we know: Type 2 diabetes increases the risk of stroke and heart disease, and stroke and heart disease are the leading causes of death and disability among people with diabetes.

We also have strong evidence from many studies that people who achieve a healthy weight and exercise regularly have a lower risk of stroke and heart disease. So you'd think that overweight people with Type 2 diabetes also would benefit from a program of intensive diet and exercise.

The Look AHEAD trial explored how changes in diet and exercise affected heart disease risk in this population. The results weren't what most people - myself included - expected.

The study was a large, randomized trial -- the strongest type of study. Researchers recruited more than 5,000 overweight men and women with Type 2 diabetes. Half were assigned at random to lose weight and maintain their weight loss through intensive diet and exercise. The other group - called a "control group" - met three times a year for group counseling sessions to discuss lifestyle changes to control diabetes.

After almost 10 years, the rates of heart attacks, strokes and heart-related deaths were essentially the same in both groups. For many of us, that result was a real downer. That is, until you read the study in detail.

For example, the people in the intensive-change group lost only slightly more weight than the control group: 4 percent versus 2.5 percent. So though the research team called it "intensive diet and exercise," it did not do a lot to achieve the goal of weight loss.

A second important difference between the intensive-change group and the control group is that the latter group was taking more heart-healthy medicines. So any real benefits from the slightly better weight loss in the intensive-change group might have been canceled out by this difference in medicines.

Lifestyle changes did have some health benefits in this study. People in the intensive-change group improved their blood sugar with fewer drugs, and they lowered their risk for other diabetes complications such as chronic kidney disease and vision problems. Some patients with Type 2 diabetes who achieve a healthy weight and exercise regularly can control their blood sugar without needing medicines any longer.

So I've told my patients that I don't think this study means that any of us should stop seeking a healthy weight and exercising regularly!

Dr. Komaroff is a physician and professor at Harvard Medical School. To send questions, go to AskDoctorK.com, or write: Ask Doctor K, 10 Shattuck St., Second Floor, Boston, MA 02115.