Diabetes Is a Heartfelt Problem
By Bradley A. Radwaner, M.D., F.A.C.C.
Diabetics face a special risk of heart disease, at least double that of the general population. Poorly controlled blood sugar over the long term exacts a toll on the entire circulatory system, from the large arteries that supply the heart and brain, to the tiny capillaries that deliver nutrients to the body's individual cells.
When control is poor, the interior walls of blood vessels become bathed in high concentrations of blood sugar. This sets the stage for atherosclerosis, a build-up of fatty plaque that can clog arteries and eventually lead to heart attacks and strokes.
Heart disease seems to act in slightly different ways in diabetics. Coronary artery disease is usually more marked with a greater build-up of atherosclerotic plaque and other debris on arterial walls. The heart muscle itself is more likely to be affected by disease in the person with diabetes.
As a result, diabetics suffer a higher-than-normal death rate from heart disease and are less likely to survive a heart attack. They also experience more silent or undiagnosed heart attacks. In fact, heart attacks and strokes are by far the leading cause of death in diabetics.
Although the prognosis may sound grim, heart disease is not inevitable for those with diabetes. Patients with knowledge of their disease and its effect on the cardiovascular system can make choices that will make a difference on risk and quality of life.
Except for the damage done by high blood sugar, the heart disease risk factors faced by diabetics are the same as those facing the rest of the population: high cholesterol and triglyceride levels; hypertension; smoking; and obesity.
Physicians now know that it's not only total cholesterol levels that count, but the high density lipoprotein (HDL, the good cholesterol), and low density lipoprotein (LDL, the bad cholesterol). Studies show that those with high levels of HDL and low levels of LDL have the fewest heart attacks. Many diabetics have the Metabolic Syndrome which consists of three of these components: obesity, hypertension, diabetes or insulin resistance or low HDL levels and is a strong predictor of coronary artery disease. Many diabetics have a high level of smaller sized dense LDL particles, the type most likely to build up blockages in the coronary and carotid arteries.
Analysis of data from the Framingham heart study shows that women with diabetes tend to have very low HDL and abnormally high levels of LDL.
Heart disease is considered rare in women who have not yet reached menopause. Women enjoy the protective benefit of female hormones during the child bearing years.
Unfortunately women with diabetes face a particularly high risk of heart disease, even before reaching menopause. The increased risk can probably be attributed to high levels of LDL, a powerful indicator of heart disease.
There are a number of ways diabetics can improve their HDL and LDL levels. Recent studies indicate that good blood sugar control appears to increase the level of HDL. Exercise is also known to improve the level of HDL and significant weight loss will greatly lower the bad LDL cholesterol.
Eating a diet low in cholesterol and saturated fats will also help keep LDL cholesterol in check. This can pose a special challenge to diabetics since the diabetic diet tends to be lower in sugar and carbohydrates and higher in fat than the diet recommended for the general population. As a result, diabetics need to be vigilant about the types of fat they eat, concentrating on polyunsaturated fats found in most vegetable oils and some fish, and avoiding saturated fats, including animal fats, coconut and palm oils.
KEEP BLOOD PRESSURE UNDER CONTROL
People with diabetes are more likely than others to develop hypertension. This factor shows up in the higher rate of deaths from heart attacks and strokes and the increased risk of kidney and eye problems faced by diabetics. One study found that people who had suffered from diabetes for 30 years or more were twice as likely to suffer from hypertension as their peers.
Lifestyle changes are known to have a positive effect on high blood pressure. Patients are advised to restrict the amount of salt consumed, to maintain normal weight, to avoid unnecessary stress and to exercise regularly.
Diabetics who smoke, especially diabetic women, simply compound their risk of heart disease. Smoking constricts blood vessels and restricts available oxygen in a circulatory system already at risk because of diabetes.
Obesity is not usually a problem for Type I diabetics, who have to carefully balance food intake and insulin doses from meal to meal, but is a major factor in Type II, or adult onset diabetes. Obesity itself is a risk factor for cardiovascular disease and is associated with high cholesterol levels. An epidemic of obesity now exists in the U.S. with one-third of the population now obese, as defined by about 30 lbs overweight.
LOOKING TO THE FUTURE
There is now very strong evidence that aggressive control of lipid abnormalities and hypertension can prevent many of the heart attacks and strokes that diabetics would otherwise suffer. Tight control of their blood sugar will help prevent the kidney and eye complications that develop in the smallest blood vessels of diabetics.
Innovations in the diagnosis of heart disease (for example, the wide-spread use of echocardiography that allows earlier diagnosis) along with new classes of medications such as ACE-inhibitors, offer diabetics better opportunity for successful treatment.
Aggressive use of statins and other cholesterol lowering medications can reduce the risk of the greatest threat to diabetics, heart attacks and strokes.
We are all at risk for heart disease. The fact that a diabetic is at increased risk need not be cause for fear but should encourage vigilance in controlling risk factors. As knowledge increases about the way diabetes acts on specific areas of the body, diabetics will be better able to make the necessary lifestyle changes.