Covid-19 hit diabetics with a double whammy and revealed deadly gaps in South Africa’s health system

Over the past two years Covid-19 has brought the heightened risks faced by people with diabetes into sharp relief. While diabetics are not at increased risk of getting infected with Covid-19, once they do contract it, they face a higher risk of severe disease and death – particularly if they have uncontrolled diabetes.

Available data suggest that, if a diabetic’s blood sugar is not controlled, they are more likely to have poor outcomes on contracting Covid-19, according to Dr Alisha Wade, endocrinologist and clinician scientist at the Medical Research Council/Wits Rural Public Health and Health Transitions Research Unit in the School of Public Health at the University of the Witwatersrand in Johannesburg.

“Multiple studies have shown a ‘dose-response’ curve between the degree of hyperglycaemia and the severity of Covid,” says Dr Ankia Coetzee, senior lecturer and endocrinologist in the faculty of medicine and health sciences at Stellenbosch University. “Individuals with prediabetes are at risk of severe Covid, albeit less so than individuals with diabetes, arguing for better glucose control in all hyperglycaemic states.”

The matter of diabetics’ vulnerability to Covid-19 is multifactorial, says Professor Joel Dave, who launched the Diabetic Centre at Groote Schuur Hospital and is head of the department of endocrinology at the health facility. He emphasised that much of the current data on this issue remain observational, since Covid-19 is a relatively new disease.

One issue is that people with high blood sugar have a greater number of angiotensin-converting enzyme 2 (ACE2) receptors, which are the receptors the virus uses to enter the body’s cells, says Dave. This means there are more points of entry into the cells for the virus. This can result in diabetics having more severe infections with higher viral loads than people with normal glucose levels.

High blood sugar also impairs the functioning of the white blood cells and, by extension, the body’s immune system. This reduces the ability of diabetics to fight off any type of infection, including Covid-19, says Wade.

Diabetes is often associated with older age, excess weight and other comorbidities, such as high blood pressure and kidney disease, she says. These factors can increase the vulnerability of diabetics to severe Covid-19.

In South Africa, 75,835 Covid-19 patients admitted to hospital were recorded as having diabetes. Of these, 25,472 died. This equates to a case fatality ratio of 33.6% of admitted diabetics who died of Covid-19, according to Foster Mohale, spokesperson for the national Health Department. Diabetics were 40% more likely to die from Covid-19 in hospital than non-diabetics.

Mortality among diabetics was highest in the second Beta-dominated wave and third Delta-dominated wave, at 39.5% and 37.3%, respectively. The fourth Omicron-dominated wave had the lowest mortality in this group, at 18.4%.

Mohale referenced a sentinel surveillance study conducted at 16 public hospitals by the National Institute for Communicable Diseases, saying: “Among 2,954 patients who were screened for diabetes, 215 (7.3%) had newly diagnosed diabetes when admitted for Covid-19 (not previously diagnosed). Among 901 patients who had [an] HbA1C [test] done as a marker for level of diabetes control, 777 (86.2%) had poorly controlled diabetes.” A paper on the study has been accepted by the South African Medical Journal but is not yet published.

Prevention, detection, vaccination

Systemic challenges