Diabetes study is a tossup
Study shows no benefit for stroke, heart attack risk
Losing weight can improve some health factors, but not heart, stroke risk
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.
The study showed that obese people with diabetes who lost a modest amount of weight didn’t lower their risk of a heart attack or stroke, but the weight loss did help improve many other health factors.
“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 chairman of the Look AHEAD (Action for Health in Diabetes) study. The research was financed by the National Institutes of Health.
In diabetes 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% to 95% 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% 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 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% of their starting weight (about 16 pounds) in the first year and maintained a loss of nearly 5% (about 10 pounds). Participants in the diabetes education group lost about 1% (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 past 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 4, possibly because more 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.”
Wing says the study holds 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.”
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 in overweight individuals with and without diabetes. Let’s not throw out the baby with the bathwater.”