Glucose Dips Overnight a Risk for Diabetics
Dipping blood sugars cause surprisingly irregular heart rhythms in diabetics and the dangerous overnight low glucose levels often go undetected. That is the finding of research led by Professor Simon Heller at the University of Sheffield in the UK. A release from the university explains that this discovery sheds important new light on the 'Dead in Bed' syndrome in which people without any history of long-term complications die suddenly from the disease.
Previous studies have apparently ruled out a direct effect of hypoglycemia (very low levels of sugar in the blood) as a cause of death in patients with Type 2 diabetes.
Few of the patients taking part in the present study reported symptoms of low blood sugar levels or irregular heartbeats – and they were only detected through continuous glucose monitoring and electrocardiograms used by Sheffield researchers which tracked blood glucose levels and heart rates over a week in a group of older patients with Type 2 diabetes and a history of cardiovascular disease.
The breakthrough research was conducted by Elaine Chow, a specialist registrar at Sheffield Teaching Hospitals and the University of Sheffield. The findings are being published in the May issue of Diabetes, the journal of the American Association of Diabetes.
The release quotes Professor Simon Heller, Professor of Clinical Diabetes and Honorary Consultant Physician, Sheffield Teaching Hospitals NHS Foundation Trust, as saying, "We don't want to alarm patients, but what we've found is potentially important in explaining a possible mechanism by which low overnight blood sugars lead to prolonged, slow heart rates that could disturb blood flow to the heart, causing life-threatening heart attacks. While we expected to find some low overnight blood sugars we were startled to find how extensively it was occurring overnight and that it was sometimes lasting for several hours. When this occurred, we also saw evidence of prolonged periods of very slow heart rate rhythms in patients. While a cause for concern, these slow heart rates were not associated with any very serious heart rhythm disturbances in the study. But the findings suggest that even those on standard insulin therapy who are not aiming for intensive glucose targets should be aware of the risk of running low sugars overnight, particularly if they have known cardiovascular disease."
Previous research has focused on the effects of high blood sugars on patients with diabetes, so more research was needed to understand how low blood sugars in patients with Type 2 diabetes caused irregular heartbeats, Professor Heller emphasized.