Each year, at least 100,000 people in the UK and more than 795,000 in the US suffer from a stroke [1, 2]. In the UK, a person suffers from a stroke every five minutes, while in the US, someone has a stroke every 40 seconds.
Someone dies from a stroke in the US every 3.5 minutes. In both countries, stroke occurs in almost one in every four people who have had a previous stroke.
Hence, the last stroke is one of the significant risk factors for another stroke. Most strokes are categorized as ischemic strokes, where blood flow to the brain is stopped.
Stroke remains one of the leading causes of death in the US and the UK. Although strokes can occur at any age, the risk of stroke increases with age.
More than a third of those hospitalized due to a stroke belong to the older adult age group or those 65 and older.
What are the risk factors of stroke?
Risk factors for stroke include the following :
- High blood pressure
- Heart and blood vessel diseases, such as atrial fibrillation, coronary heart disease, carotid artery disease and heart valve disease
- High LDL cholesterol levels
- Arteriovenous malformations or brain aneurysms
- Conditions or viral infections that cause inflammation, such as rheumatoid arthritis or lupus
- Age – in adults, the risk of stroke increases with age
- Race and ethnicity: In the UK and the US, stroke incidence is higher in the black and minority ethnic groups compared with the general population
- Sex: women who live longer are at increased risk of stroke. Younger men are at increased risk of stroke compared with younger women.
- Genetics and family history
- Other risk factors for stroke include anxiety, high-stress levels, depression, living in or working in areas with high levels of pollution, intake of blood thinners, overweight and obesity and unhealthy lifestyle habits.
Type 2 diabetes and stroke
The American Diabetes Association reiterated that individuals who have type 2 diabetes (also called diabetes mellitus) are twice as likely to have a stroke compared with those with no diabetes.
Over time, unmanaged type 2 diabetes damages the blood vessels, increasing the risk of a stroke, especially if the cerebral blood vessels are involved.
Both lifestyle modifications have been shown to lower the risk of diabetes complications, including a stroke. In addition, taking prescribed medications such as metformin would help manage blood glucose levels, resulting in better uptake of insulin in the cells and lowering blood glucose levels.
Meanwhile, hypertension is one of the significant risk factors for stroke. High blood pressure can result in a stroke in different ways.
First, it can damage the tiny blood vessels inside the brain by forming blood clots in these blood vessels. It can also lead to brain bleeding once the larger blood clots are detached and travel to the blood vessels inside the brain leading to a brain aneurysm.
The study and results
A recent study  published in the Neurology journal found that the risk of stroke in individuals with hypertension and diabetes may decrease with age.
The study’s lead author, Dr George Howard of the University of Alabama at Birmingham School of Public Health, explains that “high blood pressure and diabetes are two important risk factors for stroke that can be managed by medication, decreasing a person’s risk.”
Dr Howard continued, “our findings show that their association with stroke risk may be substantially less at older ages, yet other risk factors do not change. These differences in risk factors imply that determining whether a person is at high risk for stroke may differ depending on their age.”
Results revealed that the magnitude of the association between stroke and diabetes in older adults was significantly lesser than in younger people.
In addition, the same study reported that the extent of stroke risk decreased in older adults suffering from heart disease compared with the younger age groups. The same trend was likewise observed for hypertension and the risk of stroke in older adults.
However, the same study reported no significant age-related differences in the association of smoking, left ventricular hypertrophy, atrial fibrillation and risk of stroke between older and younger adults.
A total of 28,235 individuals who belong to the Black and Minority ethnic groups and the white population were recruited in the study. More than half (59%) belonged to the general white people, while 41% were black.
All participants were involved in the REGARDS (Reasons for Geographic and Racial Differences in Stroke) cohort study and were recruited from 2003 to 2007. All were followed up for an average of 11 years to examine if they had an incident stroke.
The lead study author cautioned, “It is important to note that our results do not suggest that treatment of high blood pressure and diabetes becomes unimportant in older age.
Such treatments are still very important for a person’s health. But it also may be wise for doctors to focus on managing risk factors such as atrial fibrillation, smoking and left ventricular hypertrophy as people age.”
Investigators of the study examined the stroke risk factors of all participants at baseline or the beginning of the study.
Risk factors used in the study
All participants underwent a physical examination to assess stroke risk factors. These risk factors included
- Atrial fibrillation
- Left ventricular hypertrophy
- Heart disease
- High blood pressure
Consequently, race was identified as a risk factor as older studies have shown that black and minority ethnic groups have a higher stroke risk than the general white population.
All participants were stratified into three groups:
- The younger age group (ages between 45 to 69 years old).
- The middle age group (ages between the late 60s and 70s).
- Patients who were 74 years old and older.
Researchers performed follow-ups of the participants every six months. Results showed 1,405 ischemic strokes among all participants during the 11-years follow-up period.
Results indicated that those in the younger age group with diabetes were twice more likely to suffer from a stroke compared with their counterparts who did not have diabetes.
Risk of stroke by age group
Meanwhile, patients in the older age group had a 30% increased risk of getting a stroke compared with those in similar age groups who were not diagnosed with diabetes.
In addition, the younger age group who were diagnosed with high blood pressure had an 80% increased risk of stroke compared with those of similar age who did not have high blood pressure.
Meanwhile, the risk of a stroke decreased by 50% for individuals with high blood pressure who belonged to the older age group compared with their counterparts without high blood pressure.
Black patients in the younger age group were at increased risk of a stroke compared with white patients in the same age group. In the older age group, more white patients suffered from a stroke compared with patients belonging to the black and minority ethnic groups.
Based on the study’s findings, 3.6% of younger patients diagnosed with high blood pressure suffered from a stroke. In contrast, only 2.0% of patients in the same age group who did not have high blood pressure had a stroke.
In the older age group, the study authors estimated that 9.3% of individuals diagnosed with hypertension suffered a stroke compared with only 6.2% of individuals with normal blood pressure in the same age group.
Findings from this study showed that while diabetes and hypertension are major risk factors for stroke, their association with stroke in the older age group appeared to be substantially less compared with those in the younger age group.
How to prevent stroke
The Centers for Disease Control  recommends preventing a stroke. One of these programs includes the Start Small, Live Big campaign aimed at those 55 and older.
The program recommends these adults take small steps, such as scheduling medical appointments and starting to eat healthy so they can enjoy a healthier lifestyle and reduce their risk of a stroke.
The same organization recommends the Live to the Beat program; a campaign focused on reducing the risk of a stroke among adult Black community members. This program encourages these individuals to choose their healthy lifestyle to ensure they live according to their beat while staying healthy.
In addition, the Centers for Disease Control recommends the following to prevent the risk of a stroke:
- Choose healthy foods and drinks – avoid foods high in trans fat and cholesterol and limit salt in your diet.
- Keep a healthy weight – being overweight or obese increases the risk of a stroke. Start eating healthy and engage in physical exercise to reduce body fats and lower body weight.
- Get regular physical activity – the World Health Organization recommends at least 160 minutes of moderate-intensity weekly exercise to stay physically healthy.
- Limit alcohol – too much drinking of alcohol can increase blood pressure. Limit intake of alcohol to only two drinks a day.
- Don’t smoke – smoking is a significant risk factor for a stroke. Ask help from your doctor to help you quit smoking.
- Control your medical conditions – control type 2 diabetes, hypertension and other medical conditions that increase the risk of a stroke.