Cardiovascular disease in diabetic patients
Diabetes mellitus is one of the most common chronic diseases affecting an estimated 382 million persons as of 2013. This number is expected to gradually increase over the next decade and to approach half a billion by 2030. Though the impact of diabetes on the eyes, kidneys and nerves is well known, it is its cardiovascular complications which are ultimately responsible for most of its associated death and disability. These cardiovascular complications include coronary artery disease, heart attacks, heart failure, stroke, and peripheral arterial disease. For these reasons, efforts at preventing and treating the cardiovascular complications of diabetes are essential in reducing the burden of this disease on our population.
The link between diabetes and cardiovascular disease was first suggested in 1881 by Ernest von Leyden, a German professor of medicine. However, it was not until the Framingham Heart Study was undertaken in 1948 that epidemiologic data would begin to emerge to substantiate these claims. This large long-term population survey showed that having diabetes increases the risk of developing coronary artery disease, heart attack, stroke, peripheral arterial disease between two and fivefold. Furthermore, contemporary data now indicates that 68 per cent of people age 65 or older with diabetes die from heart disease and 16 per cent die of stroke. Diabetes is, therefore, today regarded as one of the major modifiable risk factors for cardiovascular disease.
How does diabetes cause cardiovascular disease?
The mechanisms by which diabetes causes cardiovascular disease are complex. However, they include accelerating the rate at which fat and cholesterol are deposited in the walls of the arteries, which narrows the vessel and compromises the blood flow to the tissues or organs. Additional mechanisms include dysfunction of the lining of the arteries, direct toxic effects of persistently elevated blood sugar levels on the heart muscle cells, and abnormalities in the clotting system.
How is cardiovascular disease diagnosed in Diabetic patients?
Coronary artery disease (the most common form of cardiovascular disease) typically causes pressing, central, chest pain (angina) which comes on with activity and is relieved by rest. However, diabetic patients often have damage to the nerves which supply the heart (neuropathy). Such patients may not experience pain but rather other symptoms such as shortness of breath, vague chest discomfort, nausea, vomiting, fatigue and dizziness. the prolonging of life. These goals can be achieved through a combination of lifestyle changes, medications and procedures.
Relevant lifestyle changes include healthy dieting, exercise, weight management and the cessation of cigarette smoking. The diet should consist primarily of fruits and vegetables, whole grains (e.g. corn, oatmeal, bulgur, wheat, brown rice) and white meats. Additionally, the intake of foods containing large amounts of salt, sugar, fat or cholesterol (such as fast foods and processed foods) should be limited. From an exercise standpoint, a minimum of 150 minutes of exercise per week in the form of moderate intensity exercises such as brisk walking, jogging, swimming or cycling is strongly advised.
Several medications are helpful in treating cardiovascular disease in diabetic patients. These include those which alleviate specific symptoms and others which prevent complications and prolong life (aspirin, statins and others). Finally, procedures which restore blood flow such as the use of clot busters, stenting and bypass surgery, are sometimes required in extreme cases.
In summary, the management of cardiovascular disease in diabetic patients can be difficult. However, patients can be reassured that early symptom recognition, prompt health seeking behaviour, the appropriate use and interpretation of diagnostic tests, and the utilization of contemporary treatment modalities can significantly reduce the mortality associated with this condition and therefore lessen its impact on our population.
Dr Handle Emery
Cardiologist, The Heart Foundation of Jamaica