When we think and talk about diabetes we tend to mention the word ‘sugar’ a lot. However, increased studies in to the pathology of diabetes are changing our understanding of the disease. While it is a condition characterised by high blood glucose levels, the direct way diabetes causes us harm is through the consequent damage to our blood vessels. Thereby, the disease may potentially have an impact on all organs in the body.
Cardiovascular diseases (CVD) such as strokes, heart attacks, lower limb amputations are unfortunately the most common causes of death and disability in patients with Type 2 diabetes. It is well documented that over 50-60% of patients with Type 2 diabetes will die of cardiovascular disease.
The link between diabetes and vascular disease
Chronically elevated blood glucose levels causes low grade inflammation. The glucose directly attaches itself to circulating proteins resulting in direct damage to blood vessels. This makes it more prone for plaques formation which causes them to become narrower. Blood flow becomes more turbulent thereby, leading to even more damage.
On the other hand, hyperglycaemia is a state where there is activation of clotting factors, all of these factors contribute to an environment where blood clots are more likely to form and block narrow blood vessels.
Other Factors: The Perfect Storm
Unfortunately, diabetes is usually accompanied by other metabolic disturbances such as abnormal cholesterol levels with an imbalance between ‘good cholesterol’, high density lipoproteins (HDL-C) which mops up ‘bad cholesterol’, low- density lipoproteins (LDL-C).
There is also an increased incidence of high blood pressure, obesity, high uric acid levels, all of which independently increase the risk of CVD, even in the absence of diabetes, when present together result in the perfect storm.
Smoking and a sedentary lifestyle are also two major contributors to cardiovascular disease and are unfortunately still too common in our diabetic population. Smoking causes narrowing and damage of blood vessels, and with diabetes there is an exponential increase in vascular disease, leading to heart attacks and lower limb amputations.
How Can We Decrease the Risk?
The most obvious way to decrease the risk of cardiovascular disease is to maintain blood glucose levels within normal/safe ranges.
There is clear evidence to prove that decreasing blood glucose levels decreases the risk of damage to small vessels. To protect larger blood vessels, blood pressure control seems to be of even more significance.
However, there has been ground-breaking changes in the treatment of T2DM: New medications such as sodium-glucose co-transporter 2 (SGLT2) inhibitors and Glucagon-like peptide-1 (GLP-1) analogues have resulted in major changes in international management guidelines(1). This is because these new molecules have been shown in clinical trials to reduce mortality, heart failure and the progression of renal disease in high risk patients.
GLP-1 agonist liraglutide (Victoza) showed a reduction in cardiovascular death, heart attacks and strokes when compared to placebo in a large study (LEADER(2)) of over 9000 patients with T2DM.
Among the SGLT2-I, Empagliflozin (Jardiance, new to Mauritius this year) was compared to placebo in the EMPA-REG (3) Outcome trial and Canagliflozin (Invokana) in the CANVAS (4) trial, and both were shown to decrease cardiovascular and renal disease in patients with T2DM with established/at high risk for cardiovascular disease (CVD).
More recently, Dapagliflozin(Forxiga) was compared to placebo in a trial composed of over 17,000 patients with type 2 diabetes (5). There was a significant reduction for hospitalisation for heart failure and cardiovascular death as well as a reduction in the risk of progression of renal disease
Unfortunately at present, the use of these medications is still limited mainly by their costs.
Despite improvement in the death rates and rates of complications in people suffering from diabetes, there is still significant years of life lost due to diabetes with the main culprit being cardiovascular disease.
Targeting blood glucose control is an important way to decrease this risk however, blood pressure, cholesterol, weight control, smoking cessation are as important. It is time the focus broadens and we address all these other contributing factors.
Dr Anjuli Gunness
Consultant – Diabetology and Endocrinology