Diabetes and Stroke
Stroke is one of the most serious and life-altering complications associated with diabetes. People living with diabetes have a significantly higher risk of stroke compared to the general population, and outcomes are often more severe. Understanding why this risk exists—and what can be done to reduce it—is an important part of long-term diabetes care.
What is a Stroke?
A stroke occurs when blood flow to part of the brain is interrupted, depriving brain cells of oxygen and nutrients. Within minutes, these cells begin to die.
There are two main types of stroke:
- Ischaemic stroke (most common): caused by a blockage in a blood vessel supplying the brain
- Haemorrhagic stroke: caused by bleeding into or around the brain
A related condition, called a transient ischaemic attack (TIA), is sometimes described as a “mini-stroke.” Symptoms are temporary, but it is a serious warning sign of future stroke risk.
Why Does Diabetes Increase Stroke Risk?
Diabetes affects blood vessels throughout the body, including those supplying the brain. Several overlapping mechanisms contribute to increased stroke risk:
1. Damage to Blood Vessels
Persistently elevated glucose levels can damage the inner lining of blood vessels (the endothelium). Over time, this leads to:
- Narrowing and stiffening of arteries
- Reduced ability of vessels to dilate properly
- Increased vulnerability to injury
This process is part of atherosclerosis, where fatty deposits build up in artery walls.
2. Increased Atherosclerosis
People with diabetes tend to develop atherosclerosis earlier and more aggressively. Plaques can:
- Narrow arteries supplying the brain
- Rupture and form clots
- Travel (embolise) to smaller vessels in the brain
These processes are a leading cause of ischaemic stroke.
3. Pro-thrombotic State (Increased Clotting)
Diabetes is associated with changes in blood that make it more likely to clot:
- Increased platelet activation
- Higher levels of clotting factors
- Reduced ability to break down clots
This creates a “pro-thrombotic” environment, increasing the likelihood of a vessel becoming blocked.
4. Inflammation and Oxidative Stress
Chronic low-grade inflammation is common in diabetes and contributes to:
- Vessel wall damage
- Plaque instability
- Progression of atherosclerosis
Oxidative stress further accelerates these processes.
The Role of Other Risk Factors
Diabetes rarely acts alone. Stroke risk is often amplified by other conditions that commonly occur alongside it:
- High blood pressure (hypertension) – the strongest modifiable risk factor for stroke
- Dyslipidaemia (abnormal cholesterol levels)
- Smoking
- Obesity
- Physical inactivity
- Atrial fibrillation (irregular heart rhythm that increases clot risk)
When these factors are present together—as they often are—the overall risk increases substantially.
How Much Higher is the Risk?
People with diabetes are typically 1.5 to 2 times more likely to experience a stroke than those without diabetes. The risk may be even higher:
- With longer duration of diabetes
- With poor glucose management over time
- In the presence of other cardiovascular risk factors
Stroke also tends to occur at a younger age in people with diabetes.
Outcomes After Stroke
Diabetes not only increases the likelihood of stroke—it can also affect recovery and long-term outcomes.
Compared to people without diabetes, those with diabetes are more likely to experience:
- More severe strokes
- Greater disability
- Slower recovery
- Higher risk of complications after stroke
- Increased risk of recurrent stroke
This makes prevention especially important.
Recognising Stroke Symptoms
Stroke is a medical emergency. Early treatment can significantly improve outcomes.
A simple way to recognise stroke symptoms is the FAST acronym:
- F – Face: drooping on one side
- A – Arm: weakness or inability to lift one arm
- S – Speech: slurred or difficult speech
- T – Time: call emergency services immediately
Other symptoms may include:
- Sudden vision problems
- Severe headache
- Dizziness or loss of balance
- Confusion or difficulty understanding
If you suspect a stroke, seek urgent medical help immediately.
Reducing Stroke Risk in Diabetes
The good news is that many of the risk factors for stroke are modifiable. Managing diabetes effectively—alongside other cardiovascular risks—can significantly reduce the likelihood of stroke.
1. Glucose Management
Keeping glucose levels within target range helps reduce long-term damage to blood vessels.
While glucose management alone does not eliminate stroke risk, it plays an important supporting role alongside other strategies.
2. Blood Pressure Control
Managing blood pressure is one of the most powerful ways to reduce stroke risk.
Even modest reductions in blood pressure can lead to meaningful risk reduction. Many people with diabetes will require medication to achieve target levels.
3. Lipid (Cholesterol) Management
Lowering LDL cholesterol reduces the risk of plaque formation and stroke.
This often involves:
- Lifestyle changes
- Medications such as statins
4. Medications for Cardiovascular Protection
Some medications used in diabetes care also provide cardiovascular benefits, including stroke risk reduction in certain groups.
In addition, some people may be prescribed:
- Antiplatelet therapy (such as aspirin)
- Anticoagulants (particularly if atrial fibrillation is present)
Treatment decisions are individualised and should be discussed with a healthcare provider.
5. Smoking Cessation
Smoking significantly increases stroke risk and accelerates vascular damage.
Stopping smoking is one of the most impactful changes a person can make.
6. Physical Activity
Regular physical activity helps:
- Improve blood pressure
- Improve insulin sensitivity
- Support healthy weight
- Reduce cardiovascular risk
Even moderate activity, such as walking, can make a meaningful difference.
7. Nutrition
A heart-healthy eating pattern supports overall vascular health. This typically includes:
- Vegetables, fruits, whole grains
- Healthy fats (e.g. from nuts, seeds, fish)
- Reduced intake of highly processed foods and excess sodium
8. Weight Management
For those who are overweight, gradual and sustainable weight loss can improve multiple risk factors at once.
The Importance of Regular Health Checks
Routine monitoring helps identify and manage risk factors early. This may include:
- Blood pressure checks
- Lipid profile
- HbA1c
- Kidney function
- Cardiovascular risk assessments
These checks help guide treatment decisions and adjust management over time, and should form part of your diabetes Annual Review.
>> Your Diabetes Annual Review
A Long-Term Perspective
Stroke risk develops over many years. It reflects the cumulative effect of glucose levels, blood pressure, lipids, and other factors over time.
Reducing your risk of stroke is not a precise science, there are many interrelated factors, and some (like Genetics) aren’t able to be changed.
That said, small, consistent improvements in your general health and wellbeing can have meaningful long-term benefits.
In Summary
- Diabetes significantly increases the risk of stroke
- This is largely due to damage to blood vessels, increased atherosclerosis, and a higher tendency for blood to clot
- Additional factors such as high blood pressure and cholesterol further increase risk
- Stroke outcomes are often more severe in people with diabetes
- However, many risk factors are modifiable
- Managing blood pressure, cholesterol, glucose, and lifestyle factors can substantially reduce risk
Understanding the link between diabetes and stroke can empower you and your whānau to take proactive steps toward protecting their long-term health.
Page updated: June 2026
| LEGAL DISCLAIMER: The information on this website is provided for general educational purposes only and is intended for a New Zealand audience. It is not a substitute for professional medical advice, diagnosis, or treatment. While I strive to ensure accuracy and relevance, please always seek guidance from your healthcare provider for personal medical decisions. Use of the content is at your own risk. Links to other sites are for convenience and do not imply endorsement. |
Search
Deep Dives into Diabetes
YOUR Diabetes YOUR Life!
Articles and Posts
- Pharmac’s Decision re Changes to Type 2 Diabetes Medication Funding
- The Future of CGMs and Sensors
- Teplizumab in New Zealand – a Speculative Article
- Is Being Māori a Risk Factor for Diabetes?
- The National Diabetes Roadmap 2026
- Changing Insulin – What Your Doctor May Not Have Told You
- Type 5 Diabetes
- Discussion Paper – Understanding Diabetes Beyond the Labels
- Diabetes and Inequities Among Māori and Pacific Peoples in Aotearoa