A rule of thumb used by medical doctors saying that type 2 diabetics have twice the risk of suffering a blood clot in the heart are no longer right. This is shown by a study from Aarhus University and Aarhus University Hospital, which is today being presented at the European Society of Cardiology Congress.

2020.08.29 | Nanna Jespersgård

We can conclude that what we’re doing in Denmark overall – for everybody’s benefit – is having a particularly positive effect on people with diabetes, who now a much lower risk of suffering a heart attack, says Michael Maeng. Photo: Private.

People with the type 2 diabetes, which is today a common ailment, suffer heart attacks to the same degree as all others – neither more nor less.

This is the conclusion of a new large-scale nationwide study, which is today being presented by a research group led by Michael Maeng at the most important international cardiology congress. The study has not yet been published, but it has been peer-reviewed in the European Society of Cardiology and, based on this, included as Late Breaking Science for the thousands of professionals who will be spending the next four days knowledge-sharing and exchanging ideas.

"Today, there’s a commonly held perception that if you have type 2 diabetes, you also have a highly elevated risk of a heart attack. But it’s no longer correct – at least not in Denmark,” says Michael Maeng, who is associate professor at the Department of Clinical Medicine at Aarhus University and consultant at the Department of Cardiology at Aarhus University Hospital.

"Type 2 diabetics still have an excess mortality, which can be attributed to other factors – atherosclerosis in the legs, kidney disease, or stroke, but no longer to heart attacks."

The new research results are based on a register-based study, which has mapped the progression of the disease in more than 211,000 Danish type 2 diabetics in the period 1996-2011. Each patient with diabetes is followed over a seven-year period after diagnosis and matched with five control subjects of the same gender and age – corresponding to a comparison group of more than one million Danes. In other words, this is a comprehensive study of a group of patients who continue to grow in numbers in Denmark. According to the Danish Diabetes Association, there are 252,000 people in Denmark with type 2 diabetes, while an estimated 76,000 Danes do not know they have the disease.

From margarine to medicine and mountain bike

In the study, the researchers argue that increasingly effective anti-cholesterol and blood pressure lowering medicine in particular are probably what are preventing the heart attacks. The correlation is clear because the consumption of anti-cholesterol medicine has increased tenfold while the use of blood pressure lowering medicine has quadrupled during the course of the study. However, Michael Maeng does also point out that the research shows developments in Denmark, and that the positive development may be due to a range of factors. 

”The fact that the percentage of smokers fell from 44 to 28 percent during the period may also be a factor. And as far as I remember, in the beginning of the 1990s neither were there many middle-aged people running around nor riding mountain or road bikes,” says Michael Maeng. This is supported by figures from the Danish Institute for Sports Studies, which show that the percentage of Danes who regularly exercise has increased from approx. 40 percent in the late 1980s to 61 percent in 2016.

Michael Maeng also adds that Denmark was in 2004 the first country to ban trans fatty acids - a major component in margarine and other food products - which has been associated with increased risk of heart attacks. Further,  the reduction of saturated fat has traditionally been a cornerstone in the prevention of cardiovascular disease.

”This emphasises that it is most likely a combination of factors which have had an effect. We can conclude that what we’re doing in Denmark overall – for everybody’s benefit – is having a particularly positive effect on people with diabetes, who now a much lower risk of suffering a heart attack,” says Michael Maeng.

According to the Danish Diabetes Association, the number of people with a type 2 diabetes diagnose has almost tripled between 2000-2018. Prognosis show that 430,000 Danes will have the diagnosis in 2030.

The research results – more information

• The study is a register-based study which utilises information primarily from the National Patient Register and the Danish National Prescription Registry to identify and follow all adults in Denmark who begin treatment with medicine for type 2 diabetes. In this way, the study reflects the quality of treatment in Denmark, but not necessarily in other countries – while it should also be noted that the study at present is limited to a seven-year follow-up after the patients have been diagnosed with diabetes.
• The important partners in the study are Christine Gyldenkerne, Kevin K. W. Olesen, Jakob S. Knudsen and Reimar W. Thomsen - all of whom are employed at both Aarhus University Hospital and the Department of Clinical Medicine at Aarhus University.
• The study has not received any external funding.
• The research results have not yet been published in a scientific journal, but have been selected as one of the most important research results in the form of Late Breaking Science for presentation at the annual European Society of Cardiology conference, which is the biggest and most important academic body for knowledge exchange among cardiac researchers. On this basis, Health Communication deviates from the department's general guidelines.

Contact

Associate Professor & Consultant Michael Maeng
Department of Clinical Medicine at Aarhus University and
Department of Cardiology at Aarhus University Hospital
Email: michael.maeng@clin.au.dk
Mobile: (+45) 2670 3237