“The World Health Organization (WHO) reports that more than 53.8% – more than half – of South Africa’s adults are overweight or obese. This is particularly concerning as a number of international studies show a link between obesity and serious COVID-19 infection,” says Dr Gert du Toit, a surgeon who practises at the multi-disciplinary metabolic centre at Netcare St Augustine’s Hospital, which is accredited as a Centre of Excellence for Metabolic Medicine by the South African Society for Surgery, Obesity and Metabolism (SASSO).

“A recent study from the United Kingdom for example found that 73% of COVID-19 patients in intensive care were either overweight or obese. While we await national statistics in South Africa, there are indications that high blood pressure (hypertension), diabetes and obesity were common among those who have died from COVID-19 locally. 

“Furthermore, over 90% of deaths from COVID-19 in South Africa are recorded among individuals aged 40 years and older, which is the segment of the general population in which obesity and related comorbidities such as diabetes and hypertension tend to occur," adds Dr Du Toit.

He goes on to explain that a number of lifestyle and other conditions are associated with obesity, including type 2 diabetes, metabolic syndrome, hypertension, heart disease, impaired glucose tolerance and sleep apnoea, which is a breathing disorder. 

“The WHO therefore warns that obesity also contributes to greater vulnerability to COVID-19 infection,” he adds.

Dr Du Toit explains that many obese people, particularly those with a higher BMI and long duration of obesity, develop metabolic syndrome, which refers to a cluster of conditions occurring together, including high blood sugar levels (hyperglycaemia) and high blood pressure, abnormal cholesterol or triglyceride levels and excess body fat around the waist. The syndrome has been shown to increase the individual’s risk of developing heart disease, type II diabetes and of suffering a stroke. 

“Studies indicate that older patients and those with chronic medical conditions such as hypertension, diabetes and cardiovascular diseases are at higher risk following COVID-19 infection, which is thought to alter the immune response because of the metabolic syndrome,” he says.

“It should be noted that patients with high blood sugar levels also often show a significant worsening of symptoms, which suggests that they suffer greater morbidity than individuals who do not have diabetes. This may be why younger overweight patients under the age of 50 and with a BMI of above 35 — who have no comorbidities, or medical conditions co-occurring with their obesity — are also being relatively hard hit by COVID-19.”

“We are not entirely sure why this should be the case and the truth is that there is still much to learn about COVID-19. It is, however, thought that it may be associated with the fact that overweight people invariably have an altered inflammatory response leading to an over-aggressive immune system, which overreacts to infection and creates a cytokine storm that is responsible for acute respiratory distress syndrome.”

In addition, obesity affects respiratory function both physiologically and mechanically, the excess levels of fat on the chest wall and belly putting pressure on the lungs and making it difficult for people with obesity to fill them to capacity with air even under normal circumstances. This reduced breathing capacity may add to respiratory distress in patients with COVID-19.

Should obese South Africans be concerned then? Dr Du Toit cautions that all South Africans, and not just the obese, should take necessary precautions to avoid infection. 

"It should be noted that there are no indications that obese people acquire the viral infection more easily than the non-obese. However, once infected, obese people tend to develop more severe forms of COVID-19. Obese South Africans should observe the same measures to prevent getting infected, such as social distancing, regular hand washing, wearing of facial masks in public, and so on. Furthermore, people who have already been diagnosed with obesity-related conditions should take particular care to comply with their treatments and medical visits.”

"For obese people and the general population, it is advisable to remain as healthy as possible and avoid weight gain through maintaining a balanced diet, and remaining physically active during this challenging time. Losing weight can meaningfully reduce the risks of developing serious COVID-19 disease and/or one of the other diseases of lifestyle that are associated with obesity.”

Regarding whether metabolic surgery, such as that offered at the multi-disciplinary metabolic centre at Netcare St Augustine’s Hospital, can assist to reduce the health risks faced by obese individuals, Dr Du Toit said that it certainly can in selected obese patients. This is because metabolic surgery has an excellent success rate in resolving a host of conditions that are associated with obesity including metabolic syndrome and diabetes. 

“Given the fact that we are in the midst of the COVID-19 pandemic, the decision as to whether or not to have metabolic surgery depends upon the level of risk that the obesity poses to an individual’s health currently. Should they be at high risk of suffering from serious complications as a result of their obesity if they delay having a metabolic procedure, and can have the procedure performed safely, then we may recommend that it should go ahead,” he concludes.