Alex Nowbar reviews the latest research from the top medical journals.

JAMA

ACE inhibitors in covid—yes or no?

If you are confused about the role of ACE and ACE-inhibitors in covid, you’re forgiven. There’s so much back and forth that it is difficult to keep track. Luckily, this week JAMA heard our call. This retrospective cohort study of 4480 patients in Denmark found no association between prior use of ACE-inhibitors or ARBs with getting a covid diagnosis, having severe covid or dying from covid. This is reassuring for those with hypertension on these drugs. While death rates were higher in those who were using these drugs, the association became non-significant after adjustment for confounders including age, sex and medical history.

Covidophilic environments in New York City

The first thing to notice about this study is that it is a cohort study of almost 400 pregnant women who were tested in a universal testing programme at the delivery unit during March and April 2020. So whatever the findings, fascinating and damning as they may be, it is important to remember the sample from which the data were collected. Pregnant women are not representative of the general population. But on to the findings. Emeruwa et al found significant variation in the likelihood of getting the virus based on differences in the urban environment (although they concede that they could not perform a multivariable analysis due to the small sample size and highly correlated neighbourhood level variables). Empirically, there was higher risk with more residents per unit, more units per building, lower neighbourhood median income and higher neighbourhood unemployment rate. I am not sure how feasible it is to reduce the risk related to built environments and socioeconomic status, but it is still useful to identify those at risk and why this may be.

High covid rates in Latin American populations

I was not surprised by the statistic that people from Latin American populations were more likely to test positive for the virus than any other ethnic group, especially as testing rates would have differed between groups. Until I saw the numbers. At Johns Hopkins Hospital in Baltimore, the percentage of those tested who were positive was 8.8% in white people, 17.6% in black people, 17.2% in other ethnicities, and a giant 42.6% in Latino people. It’s hard to pass off such a huge difference as Latino populations being less likely to get tested (as they are known to be less likely to have insurance and less likely to utilise health care). It is likely that the difference in risk is due to differences in lifestyle between the ethnic groups and/or due to genetic susceptibility factors. The author suggest that Latino populations may live in more densely populated accommodation that  makes it less likely that they could follow physical distancing measures, and that they are more likely to work in jobs that put them at higher risk of infection. I agree with Martinez et al’s conclusion that “Addressing the unique needs of the Latino community may help mitigate the spread of SARS-CoV-2 infection and prevent covid-19 disease”.

JAMA Internal Medicine

Diet dogma doesn’t change

The word diet originates from the Greek diaita, meaning way of life. The more one thinks about the concept of diet as a way of life, the more meaningless studies of individual diet components seem. Hence I’m pleased that Shan et al’s US cohort study looks at the cardiovascular risk reduction with patterns of eating. This study’s strengths are large numbers of participants (although they were all healthcare professionals which makes the study less applicable to the general public) and long length of follow-up. I’m not sure these features help to make up for the limitations of diet surveys based on self-reporting but they found that greater adherence to any of the four healthy eating patterns assessed was associated with a lower risk of myocardial infarction and strokes. Sure that sounds good but what is lacking from this analysis is all-cause mortality. This is important because cancer and dementia, for example, are also affected by diet and also cause a lot of deaths.

NEJM

Covid cruise ship revisited

We learnt a lot from the infamous Diamond Princess outbreak and not just why not to go on a cruise. For example, we learned that it is possible to have the virus without being symptomatic. More than half of those who tested positive were asymptomatic at the time of testing. This formed a 96 person cohort. Sakurai et al now report what happened to them after they disembarked. The time to resolution of the infection in these asymptomatic people was a median of nine days. The time to resolution increased with increasing age. Eleven developed symptoms thereby reclassifying them from asymptomatic to pre-symptomatic. The sample size is very small so the findings aren’t that robust, but they are interesting.

Alex Nowbar is a clinical research fellow at Imperial College London, UK.

Competing interests: None declared