As of Thursday, July 3, 2014
DEAR DOCTOR K: When I was diagnosed with diabetes, my doctor said I am now also at increased risk for heart disease. What’s the connection?
DEAR READER: The link between diabetes and cardiovascular disease is stronger than many people realize: About two-thirds of people with diabetes die of heart disease or stroke. I spoke to my colleague Dr. Benjamin Scirica, a cardiologist at Harvard-affiliated Brigham and Women’s Hospital, about the link between the two conditions. He explained that diabetes harms the heart in several ways.
As you know, diabetes leads to high levels of blood sugar (glucose). It also triggers an immune response that causes chronic inflammation. Both injure artery walls. This makes arteries more likely to develop atherosclerosis, the buildup of fatty plaques in blood vessel walls that hinders blood flow and increases the risk of heart attack or stroke.
Elevated blood sugar also stiffens artery walls so they don’t expand as well, thereby increasing the risk of blood clots. Diabetes can also cause scar tissue to form in the heart muscle.
The good news is that — as is true in people without diabetes — controlling cardiac risk factors decreases the risk of heart attack and stroke. What does that mean for you?
First, if you smoke, quit.
Next, exercise regularly — ideally in sessions of 45 minutes to an hour, five times a week. Exercise strengthens your cardiovascular system. It also is key to achieving or maintaining a healthy weight, which reduces your risk of heart disease and makes your diabetes easier to control. Regular exercise prompts your cells to remove sugar from the blood, lowering blood sugar levels.
Find a heart-healthy eating plan and stick with it. Eat plenty of fruits, vegetables, fish and whole grains. Limit or avoid trans fats and saturated fats, refined grains and sugary drinks.
If you have high cholesterol in addition to diabetes, the two together greatly increase your risk of heart disease. Therefore, it is important to lower your cholesterol as well as your blood sugar. The most potent cholesterol-lowering medicines are statin drugs. These drugs not only lower your blood levels of total cholesterol and LDL (“bad”) cholesterol, they also decrease inflammation inside plaques of atherosclerosis. This lowers your risk of heart attacks and strokes.
Finally, if you have high blood pressure in addition to diabetes, these two together greatly increase your risk of heart disease. Therefore, it is even more important to control your blood pressure, which may require blood pressure-lowering medication.
While medicines may be necessary to lower your blood sugar, cholesterol and blood pressure, lifestyle changes are at least as powerful as medicines in achieving these benefits. And even if medicines are necessary, lifestyle changes can help reduce the doses of medicines that you need.
So work with your doctor to find a combination of diet, exercise and medication to keep your blood sugar levels close to normal while avoiding extremely low blood sugar. This will help reduce the risk of heart attack, stroke or death from heart disease.
Dr. Komaroff is a physician and professor at Harvard Medical School. To send questions, go to AskDoctorK.com, or write: Ask Doctor K, 10 Shattuck St., Second Floor, Boston, MA 02115.