November 5, 2020

expert reaction to study looking at Asian ethnicity and risk of COVID-19-associated stroke

A study published in the Journal of Neurology Neurosurgery & Psychiatry looks at a possible link between Asian ethnicity and risk of COVID-19-associated stroke.

Dr David Strain, Senior Clinical Lecturer, University of Exeter, said:

“It is well established that people of South Asian heritage develop stroke approximately 10 years earlier than their counterparts of European descent. This is often described as being a result of premature vascular ageing and a predisposition towards type 2 diabetes. Separately people of South Asian descent have been demonstrated to have a higher risk of hospitalisation, admission and ultimately death due to COVID-19. Further, the two of the biggest risk factors for stroke (namely ischaemic heart disease and type 2 diabetes) are more common in people of South Asian descent and are independent risk factors for COVID-19. Multiple arterial blood clots is a well-recognised complication of COVID-19 and, personally, I have seen multiple ischaemic strokes in people with COVID-19.

“The only surprise in this, therefore, is the rather large incidence of stroke in those of South Asian descent. One important confounder that is not mentioned, however is the geographical location the data was collated from. At the time these data were collected, regions of the country with a greater South Asian population were also those with a higher prevalence of COVID-19 (i.e. COVID-19 was centred around London, Birmingham and Leicester, which coincidentally have higher South Asian population – on average 4 – 7% of the population, and 26.4% in the epicentre of the UK COVID-19 first wave outbreak), therefore stroke from these regions were both more likely to be in people of Asian descent and to have COVID-19, whereas areas of the country with lower COVID-19 cases also had smaller ethnic minority populations (such as Manchester, Stoke on Trent or Glasgow (all <2% and very low prevalence of COVID-19 in the first wave).

“If the North of the UK provided the majority of the control cases whereas the South East and Midlands provided the majority of cases (in keeping with the distribution of COVID-19 in the first wave) this would easily account for the residual ethnic difference between.

“This manuscript would be substantially stronger if it reported the geographical location of cases and controls, and adjusted for background prevalence of COVID in the first wave compared to local ethnic diversity. If these observations stand up to that type of analysis they would warrant further investigation to determine if the mechanism by which COVID appears to be more deadly in people of South Asia descent is due to an increased impact on the risk of widespread blood clots.”

‘Characteristics and outcomes of COVID-19-associated stroke: a UK multicentre case-control study’ by Perry et al was published in the Journal of Neurology Neurosurgery & Psychiatry at 23:30 UK time on Thursday 5^th November.

All our previous output on this subject can be seen at this weblink:

www.sciencemediacentre.org/tag/covid-19

Declared interests

None received.