In a recent study published in the journal Diabetes, researchers found that low blood sugar or hypoglycemia could affect the body's cardiovascular autonomic control which is directly responsible for the functions of the heart. A decrease in blood sugar has an effect on the body's response to cardiovascular stress.
The study was part of Temple University Health System's $1.6 billion program committed to providing access to quality patient care and support medical research. The researchers aim to develop a body of knowledge on the effects of low blood sugar caused by strict glycemic control to cardiovascular functions as past studies have established an association between them.
Seventeen healthy volunteers were enrolled in the study and exposed to experimental hypoglycemia for two hours. They underwent specialized testing of the cardiovascular system which includes assessment of their cardiac vagal baroreflex function before and after exposure.
Findings show that during the period of hypoglycemia, there was an alteration on the body's response to changes in blood pressure and heart rate. It was shown that baroreflex sensitivity decreased significantly and systolic blood pressure threshold for baroreflex activation increased showing diminished vagal control and impaired cardiovascular homeostasis.
"These findings suggest a specific way as to how the cardiovascular system is compromised during episodes of hypoglycemia," Dr. Ajay D. Rao, Assistant Professor of Medicine in the Section of Endocrinology, Diabetes, and Metabolism at the Lewis Katz School of Medicine at Temple University said in a press release.
Hyploglycemia happens when there is low blood sugar caused by overproduction of insulin. Usually, this condition happens to diabetes patients who are under medications for blood sugar control.
What happens to the body when hypoglycemia occurs? Acute hypoglycemia could lead to marked physiological responses of the body in its effort to maintain ample supply of glucose to the brain.
Hence, blood flow to the myocardium or heart muscles is increased and at the same time, there is an increase in the production of counter-regulatory hormones like epinephrine and nor-epinephrine. These are called catecholamines that are released into the bloodstream in response to stress, just like when a person has low blood sugar.
Generally, these hormones lead to increased heart rate, increased blood pressure, vasoconstriction of arteries and veins, and increased cardiac output. These hormones may increase the likelihood of vasoconstriction and platelet aggregation - two markers that may aggravate myocardial ischemia or reduced blood flow to cardiac muscles that may lead to future heart attacks.
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