People infected with COVID-19 who have diabetes, cardiac disease, or chronic respiratory disease are more likely to be hospitalized and face a higher risk of death, according to the latest data.
Among those who died from the virus in Australia, 33% had diabetes, 30% had chronic respiratory disease, and 30% had cardiac disease.
The average age of those who died was 78.5 years, as shown in the most recent COVID-19 epidemiology report for Australia.
While it is not fully understood why individuals with these conditions are more likely to succumb, experts suggest it may be due to the decline in ‘reserve’ and immunity that comes with aging.
Reserve refers to the body’s inherent ability to adapt to illness and injury.
Yesterday, the low growth in cases continued with the number of new cases increasing slightly by 22 to 6,643, with the largest states posting single-digit increases. NSW reported six new cases, Victoria seven, Queensland six, Western Australia one, and South Australia two as of 5:30 pm AEST. A 92-year-old woman died at an aged care facility in NSW, bringing the national toll to 72.
Professor Tom Marwick, head of the Baker Heart and Diabetes Institute in Melbourne, explained that people with respiratory disease who have lost up to 20% of lung function may only experience symptoms during exercise. However, when pneumonia is superimposed on this loss, their reserve is already depleted, making them more likely to face complications.
Professor Marwick also noted that a lack of reserve is crucial for heart patients. With prolonged fever, cardiac output must increase to push blood through dilated vessels. In highly inflammatory settings, inflammation can cause coronary disease to become unstable and plaques to rupture.
While the link between diabetes and COVID-19 is not fully explained, Marwick highlighted that it is “unusual to see a non-obese patient on a ventilator.” He suggests that visceral fat may reduce diaphragm function and increase the work of breathing, and there is a strong link between obesity and inflammation.
National data show that the age group with the most infections is people in their 20s, but they rarely require hospitalization. The median age of those being admitted is 60.
There appears to be a disproportionate sparing of younger people with COVID-19, and much remains to be understood, said Professor Jason Kovacic, the new head of the Victor Chang Cardiac Research Institute. He emphasized the need to explore the roles of immune function, viral virulence, and host-viral interaction.
While most cardiac diseases do not increase the risk of contracting the infection, once infected, patients are at a higher risk of severe illness. A small proportion of cardiac patients, particularly those on immunosuppressive drugs, are at greater risk of infection from the virus.
Professor Kovacic explained that when COVID-19’s adverse effects on the lungs are combined with a heart that no longer pumps efficiently, even more fluid can accumulate in the lungs.
Key points:
- Cardiac and respiratory patients are less likely to fight off infection.
- The average age of fatalities in Australia is 78.5 years, as the elderly lose ‘reserve’ to adapt to illness.
Jill Margo and Edmund Tadros, ‘Bug’s deadlier risk for those with diabetes – Exclusive’, Australian Financial Review, The (online), 22 Apr 2020 3 ‹https://infoweb-newsbank-com.ezproxy.sl.nsw.gov.au/apps/news/document-view?p=AWGLNB&docref=news/18AF727F37408800›