The study — led by researchers at Copenhagen University Hospital in Denmark — was presented at the American Heart Association's Scientific Sessions 2017, held this week in Anaheim, CA.
The researchers suggest that the reason for the raised risk might be because diabetes causes abnormalities in blood vessels.
"Although we have become better at helping people manage both type 1 and type 2 diabetes," says study contributor Jesper Svane, a postgraduate medical research student at Copenhagen University Hospital, "it is still associated with increased risk of death, especially among young people."
Sudden cardiac death
Sudden cardiac death is that which occurs as a result of sudden cardiac arrest, a deadly condition wherein the heart suddenly stops pumping and cannot send blood to the lungs, brain, and other organs.
It results in an almost instant loss of pulse and consciousness, followed by certain death within minutes if the affected person does not receive immediate treatment.
The trigger for sudden cardiac arrest is thought to be an abrupt malfunction in the heart's electrical system, which maintains the steady rhythm of pumping essential for effective blood circulation. Such a malfunction gives rise to irregular heartbeat, or arrhythmia, and it can happen with no warning.
Sudden cardiac arrest is not the same as heart attack, which is a condition that arises when the blood supply that nourishes the heart is suddenly blocked — often because of a blood clot. A helpful way to distinguish the two conditions is to see sudden cardiac arrest as an "electrical" fault, and heart attack as a "circulation" fault.
Of the more than 350,000 cardiac arrests estimated to occur outside of hospitals in the United States every year, nearly 90 percent result in death. This figure includes around 7,000 annual cases of cardiac arrest in children.
There are problems with giving accurate statistics on sudden cardiac arrest and sudden cardiac death, though, despite it being a leading cause of death in the U.S. This is due to the fact that different parts of the country follow different standards for monitoring cases and outcomes, alongside challenges in defining "unexpected" or "sudden" death.
Rates of diabetes rising among young people
Diabetes arises when the body cannot effectively use or produce insulin, which is an enzyme that cells use in order to convert blood sugar, or glucose, into energy. This results in too much sugar in the bloodstream, which, over the longer-term, can lead to health problems that include damage to blood vessels and nerves, including those that control the heart and blood vessels.
In the U.S., there are around 29.1 million people with diabetes, many of whom are unaware that they have it. This figure includes 208,000 people aged 20 and under who have diagnosed diabetes, rates of which are rising in this group.
The team behind the new study explain that while there is evidence to suggest that people with diabetes have a higher risk of premature death than those in the general population, nobody had examined — in a "nationwide setting" — rates and causes of death among young people and children with type 1 and type 2 diabetes.
For their nationwide investigation, the researchers studied records on all young people in Denmark who were aged between 1 and 35 during the years 2000–2009, and between age 36 and 49 during 2007–2009.
Over the 10-year period, there were 14,294 deaths in the sample, and the team was able to discover the cause of death in each case from records of death and autopsies.
Of those who died, 5 percent (669 people) had diabetes. And of these, 70 percent (471) had type 1 diabetes and 30 percent (198) had type 2 diabetes.
Cardiac diseases are leading cause of death
The researchers calculated that the rate of death from all causes over the 10 years in people aged 1 to 49 was 235 per 100,000 in those with diabetes, compared with 51 per 100,000 in those who did not have the disease.
They found that cardiac diseases were the leading cause of death in those with diabetes and that eight times more people with diabetes died of this cause than people without diabetes.
Sudden cardiac death — listed as the cause of death in 17 percent of those with diabetes (118 people) — was found to be seven times more common in that group than in those without diabetes.
The team points out that because the study was confined to people living in Denmark, the findings may not apply to other countries — even western ones such as the U.S. The reason for this is not only because of demographic differences, but also because of differences in healthcare systems.
Rates of sudden cardiac death are known to vary greatly among different ethnic groups, so the findings may be even less applicable to countries with populations that are more diverse than Denmark, where 90 percent of people are Caucasian.
Nevertheless, cardiovascular disease is the most common diabetes-related complication, and there is plenty of evidence to suggest that intensive management of the risk factors results in reductions in early deaths.
This strengthens the case for monitoring people with diabetes and identifying those at higher risk of heart-related death.
"In light of the results from this study, tight control and effective treatment of blood lipids, blood pressure, and blood glucose is also important among children and young persons with diabetes."