Authors: Peter Lloyd-Sherlock and Max Bachmann, University of East Anglia
In the midst of our current anxiety about Coronavirus, there are so many different issues, so much complexity we are all struggling to understand and make sense of. One of these challenging issues is how a single health condition may interact with the multitude of other ailments, illnesses and aches and pains we all endure on a frequent basis.
None of us is perfect when it comes to health: we all have something going on most of the time. So, when does this backdrop of imperfections amount to what the new canon on COVID-19 darkly refers to as “underlying health conditions”? Or to what clinicians and scientists call “comorbidities”.
In the emerging tradition of our webinar blog series (last week’s one on ageism is here), our aim is limited to asking a few simple questions and establishing a framework for future thinking.
The most high-profile question is how do different comorbid conditions affect people’s risk of developing severe symptoms and of dying, once they are infected with COVID-19. There is already robust evidence that these effects can be significant for a range of conditions, including heart disease, diabetes, high blood pressure and lung disease.
Twenty years ago, you might have been forgiven for thinking that these health conditions were rather uncommon among older people living in low and middle-income countries (LMICs). Today we have a wealth of evidence that they are widespread. For example, a WHO survey found that nearly 80 per cent of older people in South Africa have dangerously high blood pressure. At the same time, low coverage of older people in LMICs for vaccinations against influenza and pneumonia puts them at particular risk if they develop acute respiratory symptoms as a result of COVID-19.
A related question is how different health conditions affect people’s risk of becoming infected with COVID-19 in the first place. Public debate has quite rightly focussed on the importance of things like hygiene and physical distancing. But we shouldn’t forget that natural immunity to viruses is not a fixed entity –it can vary greatly between people and for the same person at different times.
Old age itself is associated with declining immune function (what geriatricians awkwardly term “immunosenescence”). But so are many, many other things ranging from Vitamin D deficiency to general stress. And some conditions (or treatments such as chemotherapy) can lead to a virtual shutdown of the immune system.
A third big and complex set of questions refers to non-clinical interactions between comorbid conditions and COVID-19. This can include behavioural effects. For example, the evidence is rapidly emerging that older people in all countries are now at significantly higher risk of dying of conditions unrelated to COVID-19, because they are reluctant to access health services (due to fear of infection or not wishing to take precedence over “more urgent” cases) or as services are becoming less available to them.
A Canadian oncologist recently tweeted: “As a high volume cancer surgeon, I’ve noticed a significant decrease in referrals during COVID. Will we see a wave of advanced cancers presenting post-COVID?” In LMICs where access to life-saving treatment was very limited even before the new pandemic, these effects will be even more acute. This is just one example of many other interactions.
How do we help older people get medication and treatment for chronic health conditions without exposing them to infection in health facilities swamped with COVID-19 cases? What are the specific challenges of managing the condition for people with dementia? How can we avoid a vicious cycle of isolation, loneliness, stress and depression among older people?
So many questions….
For the sake of completeness, we will add just one more set of issues to the list. Over the longer-run (months and years), how will COVID-19 interact with other health conditions? This may be a less immediate concern for now but may come to prominence sooner rather than later. Evidence is emerging from China and other countries that some COVID-survivors will face permanent damage to the lungs, heart, liver, kidneys and other organs, as well as chronic fatigue.
Our webinar on 24 April will try to start to address some of these issues. We don’t expect to do more than scratch the surface of this colossal and multifaceted public health crisis.
Before then, you may find these resources helpful:
References:  The World Health Organisation defines health as: “a state of complete physical, mental and social well-being and not merely the absence of disease or
 “Comorbidity” basically refers to one or more diseases or conditions that occur along with another condition in the same person at the same time. In theory, this could include just about any condition under the sun, but most scientists prefer to focus on more serious ones.