Dr Maeve Durkan
Consultant Endocrinologist, Cork Diabetes and Endocrinologist Group
If we want to reduce the mortality of patients with type 2 diabetes, we need to look at more than just sugar control.
“If you look at patients with type 2 diabetes, they are dying from cardiovascular disease – that’s the predominant mortality,” says Dr Maeve Durkan, Consultant Endocrinologist at the Cork Diabetes and Endocrinologist Group. “In the 1990s, a patient’s chances of surviving for seven or eight years after having had a heart attack, was about 80%. But for patients with type 2 diabetes, their survival rate was only about 20-30%.
The prevalence of cardiac events is at least 30% higher in people with diabetes mellitus compared to those without.
Those statistics are alarming and, according to the American Heart Association, adults with type 2 diabetes are far more likely to die from heart disease than adults without diabetes. The prevalence of cardiac events is at least 30% higher in people with diabetes mellitus (DM) compared to those without. It’s a significant difference, which can be explained by looking at the vasculature of the heart.
For someone with type 2 diabetes, if there is prolonged hyperglycemia (high blood sugars ) these sugars can be toxic and, over time, can damage blood vessels by making them ‘stickier’. Cholesterol sticks to the ‘sticky vessels’ and ultimately other blood cells may stick to that cholesterol, causing plaque. This plaque buildup can damage the vessels carrying the blood to and from the heart, starving the heart of oxygen and nutrients.
Blood pressure and cholesterol also affect diabetes
The initial response from diabetologists has been to focus on reducing mortality rates by keeping a tight rein on a patient’s blood sugar levels and targeting glucose control by targeting HbA1C levels (the three-month test that reflects overall sugar values over the preceding three months).
But further research has gone a step further to show that traditional risks, such as blood pressure and cholesterol, are also significant risk factors in patients with type 2 diabetes – so treatment needs to incorporate more than simply managing blood sugars.
“We have had a huge change in the last five or ten years in the way we manage diabetes. We have now moved on to say we can improve the outcomes with sugar control, blood pressure control and cholesterol control,” continues Durkan. “Part of the success of the newer interventions has also been the avoidance of weight gain, (which creates a vicious circle in insulin resistance and further difficulty in managing diabetes) and, more importantly, the promotion of weight loss, and specifically fat weight loss in the abdomen, viscera and in the liver.”
New medications provide additional benefits
Alongside these developments has come greater research into medications. Many of the older, traditional treatments in the management of diabetes incurred not only a risk of hypoglycemia, but impressive weight gain, which further compounds the problems and risks associated with heart disease.
“Every new drug coming to trial has got to been seen as safe in terms of cardiovascular risk,” says Durkan. “Within the last five to ten years, two new classes of drugs have come to the fore and are not only proven to be safe from a cardiovascular aspect, but actually providing benefit. All new classes of DM drugs must now undergo cardiovascular safety trials – designed to show that they are not only safe, but that they cause no harm. Unexpectedly, we are actually seeing cardiovascular benefits that are independent of sugar lowering.”
The good news is that outcomes are moving in the right direction. According to Durkan, data for the last two decades shows a decline in cardiovascular mortality for both the general population and patients with type 2 diabetes. While heart disease remains the leading cause of death for patients with type 2 diabetes, there is knowledge and support available to help reduce that risk. Patients don’t have to suffer alone.