Diabetes is a long-term condition where a person’s blood sugar levels are too high, either due to poor insulin production (type 1 diabetes) or the body’s inability to use insulin effectively (type 2 diabetes).

Over time, uncontrolled diabetes can lead to various health problems affecting multiple organs, including the heart, kidneys, eyes and nervous system. Diabetes can raise stroke risk.

What is the connection between diabetes and stroke?¹

Diabetes may:

• Speed up the build-up of plaque in blood vessels (atherosclerosis). This can cause narrowed arteries, increase the likelihood of blockages and raise blood pressure which may lead to stroke
• Impair circulation and damage small blood vessels, causing blood flow problems to the brain
• Increase the prevalence of blood clots that cause blockages to the blood supply to the brain in ischaemic stroke
• Raise your risk of haemorrhagic strokes, in which blood vessels rupture
• Contribute to the development of other conditions, such as atrial fibrillation.

Certain factors that tend to coexist with diabetes also raise stroke risk:

• Excess weight, particularly around the abdomen, is a risk factor for both diabetes and stroke
• Lack of physical activity contributes to the development of obesity and insulin resistance
• Diets high in processed foods, solid fats and sugars can worsen diabetes control and elevate stroke risk

Smoking not only increases the risk of diabetes but also damages blood vessels and promotes atherosclerosis, increasing stroke risk.

Diabetes and stroke risk: Key points

Diabetes, and especially type 2 diabetes, is a major risk factor for stroke. People with type 2 diabetes are two to four times more likely to have a heart attack or stroke than someone without type 2 diabetes^2,3, and one third of all people living with type 2 diabetes have established cardiovascular disease⁴. Cardiovascular disease is the number one cause of disability and death for people living with type 2 diabetes⁵.

Diabetes is a highly manageable condition. If you have diabetes, preventing stroke requires proper management:

• Blood sugar control through medications such as insulin and metformin, as well as lifestyle changes to promote exercise, a healthy diet and stopping smoking.
• Blood pressure management through lifestyle modifications and medication.

In addition to the action individuals can take to reduce risk with type 2 diabetes, there are also interventions that governments can implement to help prevent stroke:

• Governments should focus on combining diabetes and heart health checks to improve early detection and prevention of heart disease in type 2 diabetes patients, as this can prevent complications, improve health, and reduce healthcare costs⁶.
• In the UK, the NHS Health Check utilises simple measurements to identify individuals at risk of heart disease, stroke, diabetes and kidney disease which has been found effective in reducing long-term disease outcomes across multiple organ systems, with a 23% lower risk of all-cause and cardiovascular death⁷.