The Sunday Mail
ACCORDING to the World Health 0rganisation (2016), more than 1,9 billion adults were reportedly overweight. And obese people accounted for 650 million of these cases.
Over 340 million children and adolescents aged between 5 and 19 years were allegedly overweight, or obese.
The World Health Organisation defines overweight and obesity as abnormal or excessive fat accumulation that may impair health.
Body mass index (BMI) is a measure of body fat based on height and weight that applies to adult men and women. BMI is a person’s weight in kilogrammes divided by the square height in metres (kg/m2).
For adults, WHO defines overweight as BMI greater than, or equal to 25. And obesity is defined as BMI greater than, or equal to 30.
Overall, about 13 percent of the world’s population – 11 percent of men and 15 percent of women – were obese (WHO, 2016).
Yet researchers have since observed that an abnormally raised BMI increases the risk of succumbing to Covid-19.
Recently, Genentech researchers in the US found that 77 percent of nearly 17 000 hospitalised Covid-19 patients were overweight (29 percent), or obese (48 percent).
Historically, overweight and obesity were generally considered a high-income problem. But they have since become a health burden in low-and middle-income countries.
In Africa, the number of overweight children under 5 years of age has increased by nearly 24 percent since 2000.
Globally, there are reportedly more people who are obese than underweight. Yet overweight and obesity are linked to more deaths worldwide than underweight.
Clinically, obesity and overweight have reportedly caused grave impact on Covid-19 progression and outcome. Obesity potentially triples the risk of hospitalisation in Covid-19 patients.
According to Obesity Reviews published on August 26, 2020, researchers found that obese people who contracted SARS-CoV-2 were 113 percent more likely to be hospitalised.
Of note, 74 percent of obese patients who contract Covid-19 were more likely to be admitted to an intensive care unit. And 48 percent percent of the patients are more likely to die.
According to Anne Dixon, a physician-scientist at the University of Vermont, USA, “obesity maybe one reason for the devastating impact of Covid-19 in the United States where 40 percent of adults are obese”.
Generally, obese people are more likely to have other diseases that are independent risk factors for severe Covid-19. These include conditions such as diabetes, heart and lung diseases.
Naturally, obesity causes impaired immunity, chronic inflammation, blood clotting, decreased lung volume, and metabolic syndrome which severely worsen Covid-19.
Crucially, obese people are more likely to develop metabolic syndrome – a cluster of conditions that increase the risk of heart disease, stroke and diabetes.
A recent study from Tulane University on 287 hospitalised Covid-19 patients found that metabolic syndrome substantially increased the risks of ICU admission, ventilation and death.
Pathogenically, people with obesity are more likely to experience severe Covid-19 due to physiological mechanisms in the respiratory system.
Mechanically, abdominal fat pushes up the diaphragm causing the large muscle which lies below the chest cavity to impinge on the lungs and restrict airflow.
Reduced lung volume leads to the collapse of airways in lower lobes of the lungs where more blood arrives for oxygenation than in the upper lobes. And this mismatch rapidly worsens Covid-19.
In healthy people, endothelial vessels normally prevent blood from clotting. But the signalling is severely altered by Covid-19 and the risk of clotting increases.
Sadly, Covid-19 patients develop sticky blood which gravely impacts the Covid-19 progression and outcome.
According to Catherine Andersen, a nutritional scientist at Fairfield University, “obese people have weakened immunity as fat cells infiltrate the organs where immune cells are produced and stored such as the spleen, bone marrow and thymus”.
Accordingly, the immune tissue is lost in exchange for adipose tissue. The immune system generally becomes less effective in either protecting the body from pathogens, or responding to a vaccine.
Clinical studies have scientifically demonstrated that obesity is highly linked to lower vaccine responses for numerous diseases such as influenza, hepatitis, and tetanus.
Usually, obesity occurs when one takes in more calories than the body can burn through exercise and normal daily activities. The body naturally stores these excess calories as fat.
Generally, the predisposing and contributing factors of obesity include heredity, unhealthy diet, liquid calories, inactivity, hormonal changes and certain medications.
Consequently, obesity can lead to complications such as heart disease and strokes, type-2 diabetes mellitus, cancers, osteoarthritis and severe Covid-19 symptoms.
More importantly, obesity can be prevented by regular exercises, healthy-eating and monitoring body weight.
Ultimately, obese people must avoid the grave impacts of Covid-19 by reducing body mass index, wearing masks properly, practising good hand hygiene and observing physical and social distancing.
Everisto Mapfidze is a registered general nurse who holds a Bsc Honours in Sociology (UZ). For feedback: 263774042111 or Facebook: Health Talk with Everisto Mapfidze.
