Diabetes and cardiovascular risk

The link between diabetes and cardiovascular disease is among the best established in all of preventive medicine — to the point that cardiovascular disease is the leading cause of death among people with diabetes, in nearly every country studied.

A multiplied risk, not simply an added one

A person with type 2 diabetes has a cardiovascular risk 2 to 4 times higher than someone without diabetes — a figure that immediately places diabetes among the most powerful cardiovascular risk factors, alongside smoking and severe hypertension. This increased risk covers the full range of cardiovascular complications: heart attack, stroke, peripheral artery disease. It's worth noting that this excess risk persists even after statistically adjusting for other classic cardiovascular risk factors, which confirms that diabetes acts through its own mechanisms, independent of its simple frequent association with other factors like obesity.

This holds true across countries. In France, where more than 4 million people are treated for diabetes, cardiovascular disease remains the leading cause of death and hospitalization among these patients. In the United States, the CDC reports that adults with diabetes are roughly twice as likely to die from heart disease or stroke as adults without diabetes. Globally, the World Heart Federation notes that about one in three people with diabetes already has cardiovascular disease.

Two points are less well known. The first concerns women: diabetes largely erases the relative cardiovascular protection they have before menopause. A 2014 meta-analysis in Diabetologia (Peters et al.), covering nearly 900,000 people, found that the excess coronary risk linked to diabetes was about 40% higher in women than in men. The second concerns heart failure: diabetes markedly raises the risk that the heart muscle weakens, even without a prior heart attack, partly through direct effects of sugar and insulin on heart cells.

Why this association is so strong

Excess blood sugar, sustained over a long period, progressively damages the walls of blood vessels, promoting the buildup of atherosclerotic plaques through several biological mechanisms: chronic low-grade inflammation, dysfunction of the vessels' inner lining (endothelium), and an unfavorable shift in the lipid profile. Type 2 diabetes also very often comes with other cardiovascular risk factors that combine and worsen one another: excess weight, high blood pressure, elevated blood cholesterol. This combination of several factors in the same person — sometimes called metabolic syndrome — largely explains why cardiovascular risk in people with diabetes far exceeds what would be expected from excess blood sugar taken in isolation.

Care that now systematically accounts for cardiovascular risk

Current medical guidelines for type 2 diabetes now systematically incorporate cardiovascular risk assessment into the care strategy, not just blood sugar control. This is exactly the logic behind the SCORE2-Diabetes tool, a version of the cardiovascular risk calculation specifically calibrated for people with type 2 diabetes, available on Hygietest alongside diabetes screening itself — a dedicated article on this hub covers this specific dimension in full.

The central role of how long someone has had diabetes

The longer diabetes has been present, the more accumulated cardiovascular risk tends to rise, regardless of the person's current age — the prolonged exposure of blood vessels to excess sugar leaves traces that build up over time, even if blood sugar control later improves. This is why age at diabetes diagnosis is a variable specifically factored into risk calculation tools dedicated to people with diabetes, unlike the standard cardiovascular risk calculation, which doesn't apply to this population.

A cycle that can be broken

This increased risk is not inevitable: good blood sugar control, combined with managing other cardiovascular risk factors (blood pressure, cholesterol, smoking, weight, physical activity), significantly reduces the risk of a cardiovascular event in people with diabetes. This is why managing type 2 diabetes generally involves a comprehensive approach, not just isolated blood sugar control — a multifactorial approach that reflects the equally multifactorial nature of the risk at play.

What the major trials showed

Two long-running trials in particular have shaped the care of type 2 diabetes. The British UKPDS trial followed more than 5,000 newly diagnosed people. It showed that good blood sugar control achieved in the first years continued to protect against heart attacks and death more than ten years after the trial ended, even after the difference in blood sugar between the groups had disappeared. Researchers called this a “legacy effect” (or “memory effect”), which confirms the value of acting early.

The Danish Steno-2 trial compared usual care with intensive management of all risk factors at once: blood sugar, blood pressure, cholesterol, smoking, lifestyle. Among patients who received intensive care, the risk of a cardiovascular event was reduced by about half. After more than twenty years of follow-up, published in 2016 (Gæde et al., Diabetologia), they had gained nearly eight years of life expectancy on average. This is one of the strongest demonstrations that a comprehensive approach, not blood sugar control alone, truly changes the future for people with diabetes.

Prediabetes is already linked to increased risk

A lesser-known but well-documented point: cardiovascular risk starts rising as early as the prediabetes stage, even before type 2 diabetes is officially diagnosed. This finding reinforces the value of early screening, including in people whose blood sugar hasn't yet reached the diagnostic threshold for diabetes — cardiovascular risk doesn't follow an all-or-nothing logic, but rather a gradual progression correlated with the degree of blood sugar dysregulation, even a moderate one.

Why some diabetes treatments also protect the heart

A notable development in recent years concerns certain newer classes of diabetes medication, which have shown, beyond their effect on blood sugar, a cardiovascular benefit of their own in large clinical studies. This finding has led to a shift in treatment guidelines: for someone with diabetes at high cardiovascular risk, the choice of diabetes medication now takes this demonstrated cardiovascular benefit into account, rather than being based solely on effectiveness at lowering blood sugar itself — a relatively recent paradigm shift in type 2 diabetes care.

A link that justifies joint monitoring

Given this close association between diabetes and cardiovascular risk, the medical follow-up of someone with type 2 diabetes generally includes regular monitoring of the main cardiovascular risk factors (blood pressure, lipid panel), alongside blood sugar follow-up itself. This joint monitoring makes it possible to detect the appearance or worsening of an associated risk factor early, rather than discovering it later, when a cardiovascular event has already occurred.

To estimate your own risk level, take the “Am I at risk of diabetes?” test.