The prevalence of stroke risk factors such as high blood pressure and diabetes are higher and increasing faster among black African and Caribbean groups, compared to people from white backgrounds.
People from black African backgrounds are also around twice as likely to experience stroke without a prior risk factor diagnosis, compared to people from white backgrounds.
Findings in a new King's College London study point to widening ethnic and socioeconomic inequalities in stroke.
Published in eClinicalMedicine , the research analysed data from more than 8,500 adults over 30 years as part of the South London Stroke Register – one of the longest-running population-based stroke registers in the world.
The research discovered that:
While diabetes rates increased for all ethnic groups over the 30-year study period, they increased most rapidly among black African participants, rising from 21% in 1995–2004 to 41% in 2015–2024. Differences in atrial fibrillation rates between ethnic groups reduced over time.
The prevalence of diabetes was 23% higher in participants with routine or manual occupations (such as bus drivers, security guards and plumbers) compared with those in non-routine or non-manual occupations (such as teachers, nurses, engineers and police officers), and 21% higher in those with lower education levels.
Diabetes diagnoses increased in all socioeconomic groups over time, but the greatest increases were seen in those with routine and manual jobs and with lower education levels. Similarly, hypertension rates increased the most in those with lower socioeconomic status.
Important gaps in the detection and treatment of stroke risk factors remain across all population groups. For example, a third of strokes occurred in people who had at least one diagnosed but untreated stroke risk factor and this proportion has not significantly changed over the last decades.
Lead author Dr Eva Emmett, Research Fellow at King’s College London, said: "Our study shows that the prevalence of pre-stroke hypertension and diabetes is higher and increasing faster in ethnic minority and lower socioeconomic groups. Together with Black people's younger age at stroke and higher likelihood of having a stroke without a prior risk factor diagnosis, these findings call for targeted and earlier primary prevention efforts.
“In terms of prevention, NHS Health Checks, which screen for hypertension and diabetes, begin at the age of 40. However, this may be too late for higher-risk groups who often experience stroke at a younger age.
“There needs to be both universal improvements in cardiovascular risk detection and more targeted prevention strategies – such as younger screening age for those most at risk – to reduce widening inequalities in stroke incidence and improve long-term health outcomes.”
The South London Stroke Register recruited participants from Southwark and Lambeth in South London, two of London’s most diverse boroughs. This diversity ensures the research reflects the communities who could benefit from its findings, across London, UK and around the world.
Over the 30-year study period, the South London population also became larger and more ethnically diverse, enabling researchers to examine how changes in population demographics have influenced inequalities in stroke risk factors over time.
Co-author Dr Matthew O’Connell, Senior Lecturer in Health Services Research and Population Health Sciences, King’s College London, said: “The South London Stroke Register is one of the world’s longest-running population-based stroke registers. By providing real-world data over 30 years, the South London Stroke Register has contributed to shaping local and national stroke policies and guidelines, the reconfiguration of London’s stroke services, and the delivery of evidence-based stroke care across the UK.”
The research findings also tie into the ‘Vital 5’ by King's Health Partners (a partnership between King’s and three local hospitals). The Vital 5 is a public health tool measuring and addressing five major disease risk factors, including blood pressure, obesity and smoking, to identify early health risks before they become more serious.
This project is funded by the National Institute for Health and Care Research (NIHR) under its Programme Grants for Applied Research.
Dr Esther Mukuka, NIHR Director of Research Inclusion, said:
"Studies like this help us better understand who is most at risk of stroke and how we can improve prevention and earlier diagnosis. More inclusive research is essential to reducing health inequalities. By taking part, people from Black, Asian and other underserved communities can help ensure new ways to prevent, diagnose and treat disease work for everyone. As NIHR celebrates its 20th anniversary, we're encouraging more people to get involved through our Be Part of Research service ."
EClinicalMedicine
Ethnic and socioeconomic inequalities in stroke risk factors and primary prevention: the South London Stroke Register cohort study 1995–2024
9-Jul-2026