As students, we are taught that race can play a role in different conditions or the prescription of medications. For example, there are different guidelines for antihypertensive treatment based on race, and the cut-off for a ‘worrying’ BMI is different based on race, too (NICE, 2019; Caleyachetty et al, 2021). However, it is important to understand whether disparities in different conditions are purely due to race or part of a wider systemic issue which disadvantages ethnically minoritised individuals, leading to poorer health outcomes. These two themes will be used as examples of some current teaching in medical schools in the United Kingdom.
Hypertension
The current NICE guidelines indicate that for those of Black African or Black Caribbean heritage regarding hypertension treatment should be offered a calcium channel blocker instead of an ACE inhibitor first line (NICE, n.d). The reasoning behind this is that it is thought that all of those with Black heritage are low responders to renin, which plays a role in blood pressure regulation (Gopal et al, 2022; Cleveland Clinic, 2022). These guidelines differ to that of hypertension treatment guidelines in the United States, South Africa, and international hypertension guidance, where race is not included as a determinant of treatment decisions (Gopal et al, 2022).
Studies have indicated that there is no significant difference in responsiveness to ACE inhibitors between Black and non-Black people in the UK (Gopal et al, 2022). Furthermore, these guidelines assume that there is a “genetic homogeneity” between races, whereas data suggests that “genetic differences between members of different races are much smaller than differences between members of the same race” (Witherspoon et al, 2007; Bhatia et al, 2014). This also is supported by the fact that race is not a biological construct, instead it is one that is enforced socially (Gopal et al, 2022; Mersha and Beck, 2020).
Finally, guidance based on race even within NICE guidelines is inconsistent: race is not considered in second-line treatment (but is considered in first-line treatment), and race is not included at all in the guidelines for prescribing an ACE inhibitor in heart failure or post-myocardial infarction (NICE 2018; NICE 2015). If it is believed that those of Black heritage do not respond as well to ACE inhibitors, should this not be represented in all forms of healthcare guidance and literature?
Obesity and BMI
There are issues with the use of BMI as a predictor of health outcomes and its use in treatment prescription as it does not take into account muscle mass versus body fat, skeletal tissue, fluid weight, as well as body composition, the latter of which can be used as a predictor for different health conditions (Nordqvist, 2022). NHS digital found that women from Black Caribbean, Pakistani and black African backgrounds are most likely to be overweight or obese, however this does not take into account social determinants and inequalities that may lead to this outcome.
The original cut-offs of BMI for being overweight, obese, and morbidly obese by the World Health Organisation were based largely on the data obtained from White populations. (Caleyachetty et al, 2021) Whilst data does suggest that a lower BMI predicts diabetes in the South Asian poulation as compared to the White population, “estimation of body fat by measurement of waist circumference and waist-to-hip-ratio (WHR) have shown to be a stronger predictor of cardiometabolic dysregulation and diabetes than BMI among South Asians” (Nair, 2021). Overall, it seems that more research is required regarding the differences in BMI in the ethnically minoritised compared to the White population, but BMI on it’s own is not the best predictor for the likelihood of the development of diabetes and needs improvement in its accuracy (Nair, 2021).
To conclude, it becomes apparent that medical education needs to more deeply consider what they are presenting as ‘fact’, and it may be more beneficial to share the context to these guidelines. At the very least, this will give students the ability to critically analyse the data that they are presented with.
References:
Bhatia, G., Tandon, A., Patterson, N., Aldrich, M., Ambrosone, C., Amos, C. (2014) ‘Genome-wide scan of 29,141 African Americans finds no evidence of directional selection since admixture’, American Journal of Human Genetics, 95, pp. 437-444.
Caleyachetty, R., Barber, T., Mohammed, N., Cappuccio, F., Hardy, R., Mathur, R., Banerjee, A., Gill, P. (2021) ‘Ethnicity-specific BMI cutoffs for obesity based on type 2 diabetes risk in England: a population-based cohort study’, Lancet Diabetes Endocrinology, 9(7), pp. 419-426.
Cleveland Clinic (2022) ‘Renin’, available at: https://my.clevelandclinic.org/health/body/22506-renin#:~:text=Blood%20pressure%20regulation%20is%20the,your%20liver)%20to%20angiotensin%20I. (Accessed 29 July 2023).
Gopal, D., Okoli, G., Rao, M. (2022) ‘Re-thinking the inclusion of race in British hypertension guidance’, Journal of Human Hypertension, 36, pp. 333-335.
Mersha, T., Beck, A. (2020) ‘The social, economic, political, and genetic value of race and ethnicity in 2020’ Human Genetics, 14, pp. 37.
Nair, T. (2021) ‘More Than Skin Color: Ethnicity-Specific BMI Cutoffs For Obesity Based on Type 2 Diabetes Risk in England’, American College of Cardiology, available at: https://www.acc.org/Latest-in-Cardiology/Articles/2021/10/18/15/35/More-Than-Skin-Color#:~:text=BMI%20and%20Ethnicity&text=It%20was%20soon%20realized%20that,fat%20compared%20to%20subcutaneous%20fat. (Accessed 29 July 2023).
NHS Digital (2022) ‘New analysis of health behaviours by ethnicity’, NHS Digital, available at: https://digital.nhs.uk/news/2022/new-analysis-of-health-behaviours-by-ethnicity-published-by-nhs-digital (Accessed 29 July 2023).
NICE (2015) ‘Chronic heart failure in adults: diagnosis and management’, National Institute for Health and Care Excellence, available at: https://www.nice.org.uk/guidance/ng106 (Accessed 29 July 2023)
NICE (2018) ‘Secondary prevention after a myocardial infarction’, National Institute for Health and Care Excellence, available at: https://www.nice.org.uk/guidance/qs99 (Accessed 29 July 2023)
NICE (2019) ‘Hypertension: Treatment Summaries’, National Institute for Health and Care Excellence, available at: https://bnf.nice.org.uk/treatment-summaries/hypertension/ (Accessed 29 July 2023).
Nordqvist, C. (2022) ‘Why BMI is inaccurate and misleading’, Medical News Today, available at: https://www.medicalnewstoday.com/articles/265215 (Accessed 28 July 2023).
Witherspoon, D., Wooding, S., Rogers, A., Marchani, E., Watkins, W., Batzer, M (2007) ‘Genetic similarities within and between human populations’, Genetics, 176, pp. 351-359.
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