A new study emphasises the importance of public health messaging to reduce levels of obesity within the population, particularly within ethnic minority groups

H_Ko BAME mask covid

New research published in Nature Communications suggests a stronger association between obesity and COVID-19 mortality in individuals from Black, South Asian, and other ethnic minority groups in England compared with White individuals.

Study details

Researchers from the University of Leicester, in collaboration with the Office for National Statistics (ONS), explored the association between body mass index (BMI) and COVID-19 mortality among 12,591,137 English adults aged over 40 years between January and December 2020.

Among the 11,074,708 individuals included in the final analysis, there were a total of 33,951 COVID-19 deaths, which included 30,067 (0.27%), 1,208 (0.29%), 1,831 (0.29%), and 845 (0.18%) deaths in White, Black, South Asian, and other ethnic minority groups, respectively.

Although BMI was significantly associated with COVID-19 mortality across all ethnic groups, the J-shaped association was sharper in the Black, South Asian, and other ethnic minority groups (P<0.001 for interaction), compared with the White population.

At a low BMI of 20 kg/m2, there was no difference in COVID-19 mortality risk in Black (hazard ratio [HR] 0.95; 95% confidence interval [CI] 0.78 and 1.16) and other ethnic minority groups (HR 1.13; 95% CI 0.95 to 1.34), and only a modestly increased risk in South Asian (HR 1.21; 95% CI 1.04 to 1.41) compared with White ethnicities.

At a higher BMI of 40 kg/m2, COVID-19 mortality risk increased significantly in Black (HR 1.74; 95% CI 1.35 to 2.26), South Asian (HR 3.05; 95% CI 2.36 to 3.94), and other ethnic minority groups (HR 2.25; 95% CI 1.58 to 3.21), compared with White ethnicities. A similar trend was observed for the risk of hospital admissions.

Lead author, Professor Tom Yates from the University of Leicester, stated: ‘This is the first study to present findings on how the risk of COVID-19 mortality in ethnic minority groups is dependent on BMI, with obesity seeming to magnify the higher risk reported in ethnic minority groups.’

The mechanisms underlying the influence of ethnicity on the association between BMI and COVID-19 mortality are not clearly understood. Previous evidence suggests a stronger innate inflammatory response to viral infection or chronic disease among ethnic minority groups, making them more susceptible to severe COVID-19. There is a possibility that adiposity accelerates the inflammatory response in these populations.

A major limitation of the study was that only 52.4% of the adult population in England had their BMI recorded by a GP in the 10 years preceding the pandemic; however, the study’s large sample size of over 12 million is likely to offset this shortcoming.

Implications and future research

‘These results further emphasise the importance of public health messages to reduce levels of obesity within the population, particularly within ethnic minority groups,’ the authors commented.

Professor Kamlesh Khunti, Director of the National Instititute for Health Research Applied Research Collaboration, East Midlands, and the Centre for Ethnic Health Research, added: ‘The research gives insights that will allow healthcare professionals and policy makers to put measures in place and create tailored plans to protect people from ethnic minority groups who are overweight or obese, and thus try to reduce mortality.’

The authors also called for further research to explore the potential interaction of obesity with post COVID-19 vaccination infection and mortality risk.

The research was funded by a grant from the UKRI-DSHC COVID-19 Rapid Response Rolling Call and is part of the Data and Connectivity National Core Study, led by Health Data Research UK in collaboration with ONS and funded by UK Research and Innovation. Thomas Yates, Melanie J Davies, Kamlesh Khunti, and Amitava Banerjee report ties with research organisations and/or pharmaceutical companies. The remaining authors report no conflicts of interest.

This article was originally published on Medscape, part of the Medscape Professional Network.

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