Help for the Diabetic Heart

Diabetes mellitus is a disease characterized by high blood sugar.  Normally, the sugar in the body is tightly regulated by insulin, a hormone secreted by the pancreas.  There are two types of diabetes, Type I occurs at an early age and is caused by the pancreas not producing enough insulin. Type II diabetes accounts for 90% of the cases of diabetes, it occurs in older adults and is the result of the body resisting the effects of insulin.  Diabetes may affect multiple organ systems. It can cause blindness, kidney failure, reduced blood flow to the legs resulting in amputation and coma caused by dangerously high blood sugar.  In addition, diabetes is a major cause of heart disease, heart deaths and stroke.  Diabetes affects 25 million people in the US (8% of the population) and the number of Type II diabetes cases has been steadily rising. Diabetes is diagnosed if the fasting blood sugar is over 125 mg/dl or if hemoglobin A1C is over 6.5%.  Since the blood test hemoglobin A1C reflects a three-month average of the blood sugar, it is the best test to follow to see if a patient’s diabetes is under control.

Type II diabetes is a major risk factor for heart disease. The ten-year risk of having a heart attack or dying from cardiac causes is as high in a diabetic as a person with known heart disease but without diabetes.  In addition, heart disease is the main cause of death in many patients with diabetes. Lowering a diabetic patient’s hemoglobin A1C level has been shown to reduce the risk for blindness and kidney disease, but it has not been shown to reduce the risk for heart disease.  So getting a patient’s blood sugar under control doesn’t necessarily reduce the risk for heart disease. Therefore, a diabetic’s risk factors for heart disease have to be treated aggressively.  Diabetics typically have high levels of low density lipoprotein (LDL, “bad cholesterol”), low levels of high density lipoprotetin (HDL, “good cholesterol”) and high triglyceride levels. This combination puts the diabetic at high risk for heart disease.  The American College of Cardiology guidelines for treating cholesterol emphasize starting a statin for diabetics with LDL levels greater than 70, a much more aggressive approach than in non-diabetics and equivalent to the recommendation for heart attack and heart bypass patients.  High blood pressure (hypertension) must be treated aggressively as well. Hypertension increases the diabetic’s risk for eye, kidney and heart disease. Two classes of medications, angiotension-converting enzymes inhibitors (such as lisinopril or ramipril) and angiotension-receptor blockers (for example, valsartan or losartan), are particularly good at protecting both the diabetic heart and the diabetic kidney.

Unfortunately, many of the medications used to treat diabetes do not reduce the risk for heart attack and heart deaths.  In fact, several diabetes medications can increase the risk for heart attack or congestive heart failure.  In a review of the nine different classes of anti-diabetes medications, none was shown to reduce the risk for heart disease, stroke or death. Fortunately, since that review was published, two new medications have emerged.  Empagliflozin (Jardiance), an oral medication, was found to reduce deaths from cardiac causes in patients with Type II diabetes and established heart disease.  Subsequently, the Food and Drug Administration (FDA) made the ground-breaking decision to award Empagliflozin an indication to reduce cardiovascular death, the first diabetes medication to receive such an indication.  Another medication, Liraglutide (Victoza), an injectable agent, was found to lower the risk for heart attack, stroke and cardiac death in patients at high risk for heart disease.

So, even though heart disease exacts a huge cost on the diabetic population, with aggressive control of risk factors (especially high cholesterol and hypertension) and the use of new medications there is hope for the diabetic heart.