Comorbidities and Covid-19: How pre-existing conditions significantly increase risk of death

  • A large data analysis shows how certain underlying health conditions can increase the Covid-19 death risk for infected patients
  • The research was done by a team from Penn State University
  • Individuals with these conditions should be prioritised for vaccination, once it becomes available

Underlying medical conditions have been known to put individuals at risk of severe Covid-19 illness and death, but there are certain medical conditions that can particularly put patients at an increased risk of death, researchers from Penn State College of Medicine have found.

According to their international study, cardiovascular disease, hypertension, diabetes, congestive heart failure, chronic kidney disease, strokes and cancer can increase a patient's risk of dying from Covid-19, the disease caused by SARS-CoV-2.

The study was recently published in Plos One

Massive international study

The research team conducted a systematic review and meta-analysis of 25 international studies and analysed data from more than 65 000 patients.

"We took an all-inclusive, global approach for this study by examining 11 chronic conditions and including patients from four continents: Asia, Europe, North America and Africa," Dr Paddy Ssentongo, a doctoral student in epidemiology at the College of Medicine and study co-author, said in a news release by Penn State University.

The studies were published between December 2019 and July 2020, and revealed which chronic conditions put hospitalised patients at risk of Covid-19 mortality.

Patients in these studies were on average 61 years old, the researchers wrote.

The following co-existing conditions that may pose a risk of severe Covid-19 disease and death among patients were explored: cardiovascular disease, diabetes, hypertension (high blood pressure), cancer, chronic kidney disease, chronic obstructive pulmonary disease, stroke, congestive heart failure, asthma, chronic liver disease, and HIV/Aids.

What they found

The researchers compared the data of hospitalised Covid-19 patients with pre-existing conditions to those without pre-existing conditions, and found the following:

  • Chronic kidney disease may triple the Covid-19 mortality risk in patients;
  • Cardiovascular disease, hypertension, and congestive heart failure may double a patient's risk of dying from Covid-19;
  • Patients with diabetes and cancer are 1.5 times more likely to die from Covid-19.

Ssentongo also emphasised the need to be aware that, based on their findings, chronic conditions are not simply just common in patients with Covid-19, but that “their presence is a warning sign for a higher risk of death".

"There is a high prevalence of cardiovascular disease and hypertension around the world and, in particular, the US. With the persistence of Covid-19 in the US, this connection becomes crucially important," Ssentongo added.

From a local perspective, a 2017 study by Wits University revealed that South Africa has the highest prevalence of hypertension in southern Africa, as well as the highest number of people whose blood pressure remains uncontrolled, even while on treatment.

The Heart and Stroke Foundation also indicates that around one in 10 South Africans live with diabetes, but that roughly one in two of these individuals is unaware of having the condition as they haven’t been diagnosed.

Vaccination importance, once available

Ssentongo explained that, based on research, the Covid-19 virus may become seasonal and require annual vaccinations.

Once an approved and effective vaccine is available, high-risk individuals with these pre-existing conditions should receive vaccination priority to prevent high mortality rates.

According to the World Health Organisation (WHO), there are currently over 100 Covid-19 vaccine candidates under development. The organisation’s director-general, Tedros Adhanom Ghebreyesus, recently stated that a vaccine may be ready by year-end, News24 reported

High-risk individuals: how to reduce your risk of infection

The risk of severe Covid-19 illness and death has been shown to increase steadily with age, irrespective of whether an individual has an underlying medical condition, although, as this recent study has shown, pre-existing conditions do increase one’s risk of severe illness and death.

If you are at higher risk, the Centers for Disease Control and Prevention (CDC) recommends taking the following measures:

  • Take everyday precautions to maintain physical distancing between yourself and others;
  • When you’re out in public, wash your hands as often as possible;
  • Limit close contact with people who are sick;
  • Avoid crowds;
  • Avoid non-essential air travel and cruise travel;
  • If you are experiencing a Covid-19 outbreak in your community, stay home as much as possible in order to reduce your risk of being exposed to the virus.

READ | Covid-19 takes heavy toll on kidneys

READ | Covid-19 patients with high blood pressure face higher risk of death, study says

READ | Covid-19 and diabetes: What the evidence says

Image: Getty

We live in a world where facts and fiction get blurred
In times of uncertainty you need journalism you can trust. For 14 free days, you can have access to a world of in-depth analyses, investigative journalism, top opinions and a range of features. Journalism strengthens democracy. Invest in the future today. Thereafter you will be billed R75 per month. You can cancel anytime and if you cancel within 14 days you won't be billed. 
Subscribe to News24
Editorial feedback and complaints

Contact the public editor with feedback for our journalists, complaints, queries or suggestions about articles on News24.