23 March 2017

Cut Down on Sugar, If You Are Experiencing Heart Rate Problems


If you are experiencing heart rate problems, you should not consume large amounts of sugar at once. A lot of sugar at once can result in dangerously low blood sugar levels and affect the heart rate. This advice comes from researchers at the Faculty of Health and Medical Sciences at the University of Copenhagen and is based on the results of a new study.

1 out of every 2,000 people suffer from long QT syndrome (LQTS), which can lead to heart failure. A research team from the University of Copenhagen has shown that there is a connection between blood sugar levels and heart rate regulation, so if you suffer from long QT intervals or long QT syndrome, you also have an increased risk of very low blood sugar levels. Now the same group has shown that the connection is even stronger than previously thought, and this has prompted the researchers to offer the following advice: 

’If you suffer from long QT intervals, you should be careful not to consume a lot of sugar at once. In fact, a medium-size soft drink is enough to cause the blood sugar to drop to dangerously low levels further increasing the QT interval. At worst, this can lead to disordered cardiac rhythm and heart failure’, Associate Professor Signe Sørensen Torekov from the Department of Biomedical Sciences and the Metabolism Center explains.

When healthy individuals eat sugary foods, it causes the pancreas to produce insulin. Insulin is the hormone that lowers the blood sugar to a stable level again after we have consumed sugar. In a previous study the team, comprised of Associate Professor Jørgen Kanters and Professor Torben Hansen, among others, has shown that the amount of insulin produced by the pancreas is regulated by potassium channels, among others things. When the potassium channels do not work, it causes excessive amounts of insulin to be produced and the blood sugar to drop to dangerously low levels. It is these potassium channels that do not work properly in LQTS patients.

Hormones Overreact
In the new study the researchers have shown that the potassium channel called hERG, in addition to being connected to the insulin level, is also connected to two other hormones, GLP-1 and GIP, which also overreact and signal to the body to produce even more insulin. At the same time, in LQTS patients the hormone responsible for protecting the body against low blood sugar levels is impaired.

’When a healthy individual experiences low blood sugar levels, the hormone glucagon reacts by signalling to the body to release more sugar into the blood. But the glucagon level in people suffering from LQTS is too low. This means that not only does the patient’s insulin level increase to twice the amount seen in healthy individuals, the hormone responsible for raising the blood sugar from a dangerously low level is equally impaired’, Signe Sørensen Torekov explains.

The research has shown a previously unknown connection between blood sugar and heart rate regulation. And it has resulted in some advice for LQTS patients: Be careful not to consume too large amounts of sugar at once, if you want to minimise the risk of low blood sugar and thus further increasing your QT interval.

The study ‘Patients with Long QT Syndrome Due to Impaired hERG-encoded Kv11.1 Potassium Channel Have Exaggerated Endocrine Pancreatic and Incretin Function Associated with Reactive Hypoglycemia’ has been published in the most prestigious journal within heart research, Circulation. 

Contact: Signe Sørensen Torekov, Email: torekov@sund.ku.dk, Telephone: +45 22 98 38 27