A diabetes 'epidemic' is sweeping Ontario

Nov 01, 2007, Donna Jean MacKinnon, Staff Reporter, Toronto Star

Once considered a disease of middle age, a diabetes 'epidemic' is sweeping Ontario, afflicting people of all age groups and costing the health-care system billions.

A Canadian study released in September provides evidence that regular aerobics and weight-training exercise help type 2 diabetics control their blood sugar.

The study, led by Dr. Ronald Sigal, associate professor of medicine and cardiac sciences at the University of Calgary, involved 251 sedentary type 2 diabetics, aged 39 to 70, who were free of heart disease. They were assigned a diet that kept their weight up.

Researchers from the Calgary university and the University of Ottawa randomly divided them into four groups: aerobic exercise, weight (resistance) training, a combination of both and a control group with no exercise.

The participants were sent to gyms for 22 weeks. During this time, the aerobic group worked on gym machines for 45 minutes, three times weekly, while the resistance group spent the same amount of time weight training. The combination group spent 90 minutes, three times a week doing both exercise programs.

At the end of the study, all patients were given a hemoglobin A1c test, which indicates the average level of blood sugar over the past two to three months.

Compared to the control group, the people in the aerobics and weight-training groups showed improvement in their blood-sugar control. And patients doing both forms of exercise showed even better reductions in their blood-sugar levels.

But researchers admit they are unsure whether it was doing both types of exercise or the longer duration (90 minutes) that contributed to the better results in the combination group.

The improvements measured by the researchers translate into a 15- to 20-per-cent decrease in risk of heart attack and stroke, and a 25- to 40-per-cent lower risk of diabetes-related eye disease or kidney disease, according to Sigal.

Data also suggest that consistent exercise could improve blood pressure and triglyceride (chemical form of fat in the blood plasma) and cholesterol levels in people with diabetes.

"Historically, diabetics were not encouraged to exercise," Sigal says.

As recently as 2005, the American Diabetes Association was saying "no" to weight training for diabetics – especially older patients – for fear of complications such as stroke or heart attack.

Today, the association recommends 30 minutes of daily exercise.

The aerobics regimen included vigorous walking, swimming and biking, while weights and elastic bands were used in the resistance program.

As beneficial as a rigorous workout appears to have been, Sigal advises type 2 diabetics who are overweight and have been inactive to start with regular walks. He also cautions older patients to talk to their physicians before beginning aerobics or weight training.

"When starting, talk to a trainer at the gym. At the Y, for example, there is usually an introduction to all machines at no extra cost."