Are low blood sugar levels a risk factor for coronary artery disease?

This study looked at the possible association between hypoglycemia and coronary artery disease (CAD). The study also examined whether this association is greater in those who are already at a higher risk of CAD. The study concluded that hypoglycemia might not be a CAD risk factor for the majority of patients but it is associated with CAD in high-risk patients

A hypoglycemic event is when blood glucose (sugar) levels become dangerously low. Hypoglycemia has been associated with increased cardiovascular events (those that cause damage to the heart). It is known that high blood sugar levels are a cause of blood vessel damage. Coronary artery disease is a disease where the major blood vessels that supply blood to the heart become damaged.

Little is known about whether hypoglycemic events are a risk factor for CAD among the majority of diabetic patients. 

This study examined the potential association between hypoglycemia and CAD. This study followed 9,173 patients with diabetes for approximately 6.5 years. Hypoglycemic events that were documented in emergency departments and during inpatient and outpatient visits were monitored. Incidence of CAD was also monitored. Patients were determined to be at high-risk of CAD if they were 55 years or older, had HbA1c (average blood glucose over 3 months) levels over 7.5% and had at least 2 other risk factors (such as high blood pressure, obesity or high cholesterol).

The risk of CAD was twice as likely in those with previous hypoglycemic events. The risk of CAD was three times as likely in high-risk patients. The risk of CAD was 4.62 times higher in high-risk patients who were older than 65 years.

This study concluded that hypoglycemia was associated with CAD in those who were already at a high risk. 

The study did not distinguish patients with type 1 diabetes from patients with type 2 diabetes. They are conditions with different causes and different treatments and therefore should be distinguished. 

If you are a diabetic and have high blood pressure, high cholesterol or obesity and are over the age of 55 years, discuss the risk of coronary artery disease with your doctor.