November 14, 2013
News Review From Harvard Medical School -- Exercise Cuts Diabetics' Heart, Stroke Risk
People with diabetes who exercise more often may reduce their risk of heart and blood vessel disease and death, a new study finds. The study included nearly 15,000 people. All were part of a Swedish registry of people with type 2 diabetes. Their average age was 60. They did not have heart disease at the start of the study. People with diabetes are known to have higher than average risks of heart attack and stroke. Researchers asked people how often they exercised for at least 30 minutes at a time. They were divided into "low-activity" (2 or fewer times a week) and "high-activity" groups (at least 3 times a week). Researchers kept track of them for 5 years. In that time, people with high activity were 25% less likely to develop heart and blood vessel disease or have a heart attack or stroke. People in the low-activity group were 70% more likely to die of a heart attack or stroke. The European Journal of Preventive Cardiology published the study November 14.
By Robert H. Shmerling, M.D.
Harvard Medical School
What Is the Doctor's Reaction?
Heart and blood vessel (cardiovascular) disease, including heart attack and stroke, is the No. 1 cause of death in the United States. And it's been that way for decades.
Some of the biggest factors that increase the risk of heart and blood vessel disease include:
- Cigarette smoking
- High blood pressure (hypertension)
- A family history of heart and blood vessel disease
- High blood cholesterol, a low level of HDL ("good cholesterol") or both
Lack of exercise and obesity are often included as risk factors for heart disease and stroke as well. At least part of the reason is that they are closely linked with diabetes, high blood pressure and high cholesterol.
As you might predict, changing these risk factors can lower your risk of heart disease and stroke. For example, people who stop smoking can reduce their risk over time back toward that of nonsmokers. And people who begin to exercise regularly can lower their risk compared with people who don't exercise.
But what if you already have diabetes? Are there ways to offset at least some of your increased risk of heart disease and stroke? Taking medicines to lower blood sugar and cholesterol and taking low-dose aspirin can help. But a new study suggests that exercise can have a big impact as well.
The study included more than 15,000 people with Type 2 diabetes, the type linked to excess weight. Their average age was 60. Researchers recorded their exercise levels, heart and blood vessel disease, and deaths over 5 years.
The European Journal of Preventive Cardiology published the study results. Here's what researchers found:
- People who were inactive had a 25% higher risk of heart and blood vessel problems than those in the high-activity group. Inactive was defined as exercising no more than twice a week for 30 minutes at a time. People with high activity exercised at least 3 times a week.
- The low-activity group had a 70% higher rate of fatal heart attacks and strokes.
- People in the low-activity group who didn't increase their exercise during the 5-year period had higher rates of heart and blood vessel problems than those who increased from low to high activity.
This research shows that even if you have a higher risk of heart and blood vessel disease because of diabetes, you may be able to reduce it through exercise. That's important because it shows that risk is not "set in stone." It can change over time, and much of it is under your control.
What Changes Can I Make Now?
I've often said that if exercise was a new medicine, it would be a blockbuster. The list of benefits is long and expanding. So get on the exercise bandwagon and start moving. If you're concerned that you aren't healthy enough to exercise, check with your doctor first.
It may seem difficult to get started. But remember that "non-exercise exercise" counts! For example, walk rather than drive or take the stairs instead of the elevator.
To increase your physical activity:
- Try to exercise most days of the week. Aim for moderate intensity (such as a brisk walk) for at least 45 minutes each day.
- Pick an activity you enjoy, such as walking or biking. If jogging is something you dread, pick something else! You're more likely to stick with something you like.
- Make exercise a social event. If you have an exercise partner (or two), you'll be less likely to skip it and will enjoy it more.
- Vary your routine. You may reduce the chances you'll get bored or have an injury if you change your activities over time.
For people with diabetes, exercise is not the only way to reduce the risk of heart and blood vessel disease. Here's what else you can do:
- Change your diet. Cut back on sweets, cholesterol and total calories. A nutritionist can be helpful.
- Monitor and control your blood sugar. Most people can keep it close to normal with diet, exercise and medicines.
- Control your blood pressure and cholesterol. Talk to your doctor and set goals. One or more medicines may be needed to reach them.
- Take low-dose aspirin and an ACE inhibitor. Talk to your doctor about whether it's a good idea for you to take these.
- Don't smoke.
What Can I Expect Looking to the Future?
As Americans get heavier, rates of type 2 diabetes are increasing dramatically. With enough attention, this trend can be reversed. Exercise is one way to help prevent diabetes and reduce related health problems.
You can expect to hear much more about the health benefits of exercise for people with diabetes or other conditions and for those who are healthy. I hope that eventually we will view exercise as a health priority rather than a chore.