Obesity might be a smoking gun with life and death power over COVID-19 patients
June, 9th, 2020
BST* Executive summary prepared by Marina T. Botana1 and Raymond C. Valentine2
1 São Paulo, SP, 04116-240, Brazil; firstname.lastname@example.org ; +55-11-97283-7799
2 Professor Emeritus, University of California, Davis, CA 95616, USA; email@example.com ; +1-802-275-2980
This blog is based on the proposition that in many countries, including the USA, with the most COVID-19 cases and deaths, obesity reliably reports who will live and who will die. There is still limited data about preexisting obesity in COVID-19 patients, but the two main comorbidities associated with the more severe cases are preexisting cardiovascular diseases and diabetes mellitus, which are both related with higher adipose tissue mass1,2 (see Figure 1). Unfortunately, obesity remains an enigma for many reasons including 1) no mechanistic explanation about its cause and 2) no cure. Even the scientific definition is murky. For example, is obesity an ailment, syndrome, disease or all the above?
Figure 1: Obesity-related comorbidities and mechanisms of a severe course of COVID-19. Patients with obesity often have respiratory dysfunction, which is characterized by alterations in respiratory mechanisms, increased airway resistance, impaired gas exchange and low lung volume and muscle strength. These individuals are predisposed to hypoventilation-associated pneumonia, pulmonary hypertension and cardiac stress. Obesity is also associated with an increased risk of diabetes mellitus, cardiovascular disease and kidney disease, comorbidities that are considered to result in increased vulnerability to pneumonia-associated organ failures. However, even in the absence of comorbidities of obesity, the presence of hypertension, dyslipidaemia, prediabetes and insulin resistance might predispose individuals to cardiovascular events and increased susceptibility to infection via atherosclerosis, cardiac dysfunction and impaired immune response (Figure obtained from Stefan et al., 20202).
Obesity tends to shorten lifespan significantly by speeding up aging, consequently, BST believes that obesity has earmarks of an age-dependent disease. There are convincing data that COVID-19 is intricately linked to a spectrum of other age-dependent diseases, ailments and addictions, not only obesity-related (i.e. cardiovascular disease and diabetes), but also smoking, respiratory syndromes and Alzheimer’s disease1,3. Taking New York city and New Jersey as examples, all the causes mentioned above are among the causes of deaths above normal in the past months (Figure 2).
Figure 2: Deaths above normal in New York and New Jersey. The percentages are shares of total excess deaths from March 15th to May 2nd (figure adapted from The New York Times – “There has been an increase in other causes of deaths, not just Coronavirus”, published on June 1st, 2020).
There are new data almost everyday showing the global statistics of SARS-CoV-2 country by country. Despite the possibility of false news or propaganda, certain trends are emerging that are difficult to deny. A rumor suggesting that the extent of the SARS-CoV-2 devastation in China compared to the USA is false news is relevant for the discussion presented here. Let us assume that the numbers of infections/deaths in China are similar to those of the USA. According to this scenario the real number for total infections in China would have been in the ballpark of five to six million patients with fatalities in the range of 500,000 people. Interestingly, the same arithmetic applies to India. A scaled down version, considering their populations, applies to many other countries including Brazil, Japan, Germany and South Korea. BST concludes that on a country-by-country basis there is a great deal of divergence in infectivity of SARS-CoV-2 (Table 1).
Table 1: Selected country-by-country summary of SARS-CoV-2 infections compared to the USA. Numbers were obtained from COVID-19 Dashboard by the Center for Systems Science and Engineering (CSSE) at John Hopkins University (JHU) on June 9th, 20204. NYC, where cases are the highest is highlighted in red. India, where cases are the lowest is highlighted in green.
The following questions summarize BST’s thinking and interest in the molecular pathology of obesity:
1. Total infections in the USA are over 1.9 million and deaths are over 111,000 people. China and India combined have a population of about 2.7 billion. If the spread and development of the disease in their population were supposedly similar to what is happening in the USA, their combined numbers of SARS-CoV-2 infections would be expected to be around 16.4 million total and deaths about one million. It seems to be a great stretch of imagination to assume that six to seven million or so SARS-CoV-2 patients and half a million bodies could be hidden from Chinese citizens and the rest of the world. BST believes that whereas there is a lot of false news circulating it might be time to admit that it is not the rest of the world that is “out of step” with respect to SARS-CoV-2 in health care, but rather the good old USA.
2. Is it possible that our lifestyle in the USA is contributing to our number-one ranking as the country with the greatest numbers of infections and deaths from SARS-CoV-2?
3. Is the SARS-CoV-2 pandemic exposing all health weakness caused by the American lifestyle?
4. Do any of the co-morbidities, including smoking, diabetes, obesity or aging further explain our vulnerability to SARS-CoV-2?
5. Not changing the American lifestyle can keep Americans more vulnerable to other future pandemics
Finally, we end the discussion with a pat on the back for English Prime Minister Boris Johnson, who learned his lesson on obesity the hard way. After recovering from a tough battle with SARS-CoV-2 PM Johnson says he was overweight at 17.5 stones (245 pounds) when he entered the hospital. Due to his height, five feet, nine inches, PM Johnson was classified as being obese. He is now a firm believer in a close linkage between obesity and SARS-CoV-2 infection and to his credit vows to develop and execute a serious anti-obesity campaign in Britain. We dedicate this executive summary to PM Johnson, a leader who could inspire the world in this field. Incidentally, BST plans two summaries on the relationship between obesity and health with this summary offering a global perspective and the a second highlighting the molecular pathology of obesity as an age-dependent disease.
BST believes that any linkage found between obesity and SARS-CoV-2 is only the tip of the iceberg. For example, SARS-CoV-2 infection is an example of biological stress—a huge field of study ranging from fundamental to field and clinical applications. As mentioned at the beginning of the text the obesity field is lacking a cohesive model for guiding research. In summary, we believe that obesity is a smoking gun explaining the catastrophic numbers of SARS-CoV-2 infections and deaths in the USA. An invaluable possible silver lining coming from this horrific pandemic would be a unified mechanism developed during the war against SARS-CoV-2 that might be directly applicable to also aging and age-dependent diseases.
1. STEFAN, Norbert; SCHICK, Fritz; HÄRING, Hans-Ulrich. Causes, characteristics, and consequences of metabolically unhealthy normal weight in humans. Cell metabolism, v. 26, n. 2, p. 292-300, 2017.
2. STEFAN, Norbert et al. Obesity and impaired metabolic health in patients with COVID-19. Nature Reviews Endocrinology, p. 1-2, 2020.
3. The New York Times – “There has been an increase in other cases of deaths, not just Coronavirus”, published on June 1st, 2020 by Denise Lu.
4. COVID-19 Dashboard by the Center for Systems Science and Engineering (CSSE) at John Hopkins University (JHU).