People with type 2 diabetes often are encouraged to lose weight to improve their health, but a puzzling new study may have some questioning that advice.
A recent study showed that obese people with diabetes who lost a modest amount of weight didn’t lower their risk of having a heart attack or stroke, but the weight loss did help improve many other health factors.
“While we did not show a benefit of modest weight loss for cardiovascular events, we did show the benefits of weight loss for improving depression, quality of life, sleep apnea, incontinence, fitness, physical function and blood-sugar control,” says Rena Wing, a professor of psychiatry and human behavior at Brown University and chairwoman of the Look AHEAD (Action for Health in Diabetes) study. The research was financed by the National Institutes of Health.
In diabetes – a disease spotlighted in November during American Diabetes Month – the body does not make enough of the hormone insulin, or it doesn’t use it properly. Insulin helps glucose (sugar) get into cells, where it is used for energy. If there’s an insulin problem, sugar builds up in the blood, damaging nerves and blood vessels. There are two major forms: type 1 and type 2, which accounts for 90 percent to 95 percent of diabetes.
Diabetes can lead to heart disease, stroke, kidney failure, foot and leg amputations and blindness. Almost 26 million children and adults (8.3 percent of the population) in the United States have diabetes.
For the study, researchers at 16 centers around the country worked with 5,145 obese people with type 2 diabetes. Their average starting weight was about 200 pounds. The study was designed to see whether weight loss reduced the risk of heart attacks and strokes.
Half of the participants were assigned to an intensive diet-and-exercise program. They attended individual and group meetings where they were taught strategies for weight loss by cutting calories and increasing physical activity. They used some meal replacements during the weight-loss and maintenance phases of the program.
The other half received a general program of diabetes education several times a year. All participants continued to follow the medical advice of their physician.
Findings: Those in the diet group lost about 8 percent of their starting weight (about 16 pounds) in the first year and maintained nearly 5 percent (about 10 pounds) of that loss. Participants in the diabetes education group lost about 1 percent (2 pounds) of their starting weight and kept it off. Everyone was tracked for up to 11 years.
After four years, the findings showed that those in the diet-and-exercise group improved their hemoglobin A1C readings (which looks at a person’s average blood- sugar levels for the last three months), fitness, systolic (top number) blood pressure and HDL (good) cholesterol more than those in the diabetes education group. The diet-and-exercise group also required less medication to control the diabetes, Wing says.
Participants in the diabetes education group, however, had better LDL (bad) cholesterol at year four, possibly because more of them were taking cholesterol-lowering drugs, she says.
There was no difference between the two groups in the incidence of heart attacks and strokes, but the incidence was low in both groups, Wing says. “The fact that they had lower rates of cardiovascular disease than we expected probably reflects improvements in medical management of diabetes.”
Physicians today are working harder to make sure the patient has good blood sugar control and has good blood pressure and cholesterol levels, she says. “There has been much more intensive medical management of people with diabetes to prevent heart disease.”
Wing says researchers will continue to monitor the study participants to see whether their weight loss lowered their heart attacks later in their lives and to assess other possible long-term benefits of weight loss.
“The study provides important information, but we don’t know from this study whether larger weight loss would have better impact, and we don’t know if these weight losses would have decreased the risk of heart attacks and strokes in people without diabetes,” she says.
James Hill, executive director of the Anschutz Health and Wellness Center at the University of Colorado and principal investigator at the study’s site in Denver, says the bottom line is still: “Losing weight is one of the best things you can do for your health if you are overweight with type 2 diabetes.”
Thomas Wadden, director of the Center for Weight and Eating Disorders at the University of Pennsylvania’s Perelman School of Medicine, adds: “Regardless of its effects on heart disease, modest weight loss and increased physical activity improve multiple aspects of health and well-being in overweight individuals with and without diabetes. Let’s not throw out the baby with the bathwater.”
Sue Kirkman, senior vice president of medical affairs for the American Diabetes Association, says the message is that there are lots of other benefits for weight loss, such as needing fewer medications and better quality of life, and “we know that weight loss helps prevent or delay type 2 diabetes.”
© 2012 USA TODAY. All rights reserved.