DALLAS, April 29 – Men with type 2 diabetes can save their lives by walking, and the faster they walk the less likely they are to have a heart attack or stroke, according to new research reported in today’s rapid access issue of Circulation: Journal of the American Heart Association.
“Previous studies found beneficial effects of physical activity in the general population, but this is one of the few studies on the benefits of physical activity in adults with diabetes,” says lead investigator Mihaela Tanasescu, M.D., Sc.D., associate professor in the College of Health Sciences at Touro University International in Cypress, Calif. “That’s significant because diabetes greatly increases risk for cardiovascular disease.”
Tanasescu and her co-authors from Harvard School of Public Health studied a subset of men enrolled in the Health Professionals Follow-up Study. It’s a study of 51,529 male health professionals 40 to 75 years old in 1986 when the project started. In this new analysis, the researchers identified 3,058 men who reported a diagnosis of diabetes at age 30 or older. Men with physical disabilities were excluded, so the findings are based on 2,803 non-disabled diabetic men.
Researchers assessed physical activity every two years between 1986 and 1998 using questionnaires that asked about average time spent per week in activities such as walking, running, lap swimming and tennis. Walking pace was gauged as “casual” – meaning 2 miles per hour (mph) or less, “normal” 2 to 2.9 mph, brisk 3 to 3.9 mph or “striding,” which was defined as 4 mph or faster.
The time spent at each activity in hours per week was multiplied by its typical energy expenditure expressed in metabolic equivalents (METS), which were totaled for a MET-hour score.
During 14 years of follow-up 266 new cardiovascular events occurred; 96 were fatal and 170 were nonfatal. There were 355 deaths from all causes.
In the study, diabetic men who were in the third highest of four categories (quintile) of total physical activity reduced their risk of cardiovascular disease by 36 percent and their risk of death by 43 percent compared to those in the lowest quintile of physical activity. There was no further improvement in the fourth and fifth quintiles. Men in the highest quintile of walking expended more than 16MET-hours/week (equivalent to four hours of brisk walking in a week) and reduced their risk of death by 43 percent. Men who walked at a brisk or very brisk pace had a significantly lower risk of cardiovascular disease as compared to men who walked at a casual pace. Thus, while high amounts of energy expenditure or vigorous exercise may not be required, walking appears to reduce risk when performed regularly and at a fast pace.
The benefits of physical activity in this study were significant, but Tanasescu says diabetic patients should consult their physicians before beginning an exercise program. “In a few cases, patients may be advised not to undertake certain types of physical activity,” she says. “But overall, risks associated with exercise are low and benefits are considerable in individuals with type 2 diabetes.”
In an accompanying editorial, Jonathan Myers, Ph.D., of the Veterans Administration Hospital in Palo Alto, Calif., wrote, “This research confirms previous studies demonstrating that significant health benefits can be achieved by modest intensity physical activity.”
He notes that several lines of evidence support the concept that physical activity has specific benefits to people with diabetes. These include better glucose control, reduced triglyercerides and weight loss. “The findings from this study should encourage healthcare providers to recognize physical activity as part of the standard treatment for patients with glucose intolerance and established diabetes,” he adds.
Tanasescu’s co-authors are Michael F. Leitzmann, M.D.; Eric R. Rimm, Sc.D.; and Frank B. Hu, M.D. The research was partly funded by the National Institutes of Health.
Note: The American Heart Association’s The Heart Of Diabetes: Understanding Insulin Resistance is a FREE 12-month program that educates people about the association between cardiovascular disease, diabetes and insulin resistance. People with type 2 diabetes are encouraged to control their heart disease risk through physical activity, nutrition and cholesterol management. To register, call 1-800-AHA-USA1 or visit americanheart.org/diabetes.