Obesity and COVID 19 Risk – Empowered Life at Sanctuary Functional Medicine Nashville Area
Why? Why? Why? Everyone wants to know why some people get COVID and some don’t, why some become critically ill and die. Researchers race to be the one who uncovers the hidden secret of COVID epidemiology. Several risk factors have bene identified such as age, uncontrolled diabetes, and vitamin D status. Obesity has also been linked to the incidence and severity of this viral disease arising out of China this year. But why obesity?
In the original outbreak in Wuhan, China, the low rate of obesity in the population did not give away hints at obesity as a risk factor. Poorly controlled type 2 diabetics did fare worse however. In the United States, with a higher rate of diabetes and obesity, the disparity has been striking. A report By Williamson et al in Nature revealed a 2.6 fold greater risk of COVID 19 in obese patients. Zhu et al reported a higher rate of poor outcomes in poorly controlled diabetes.
In medical research, correlations like this require confirmation and connections with actual mechanisms of disease. Several other studies noted in the article of interest for today confirmed this correlation in other populations comparing obese and non-obese individuals. Today’s article looked at mechanisms by which obesity could lead to such differences.
The punchline… obesity likely contributes to COVID risk through meta-inflammation, their term for metabolic inflammation induced by excess adipose tissue and consequences of the excess adipose tissue. This meta-inflammation seems to occur through various mechanisms. Building on prior research (Moser and Neidich) that obese patients suffered more from H1N1 influenza and seasonal influenza, they looked at the innate immune system as a key player in this mechanism.
Specific monocytes, a type of innate immune system cell, changed in response to obesity. These cells released more inflammatory markers. These same inflammatory markers were associated with more severe COVID 19 disease. They also looked at another immune cell called a macrophage which appear to become more inflammatory in obese patients. While inflammation increases, in many infectious conditions, high blood sugar associated with diabetes and obesity decreased the viral and bacterial killing ability of different immune cells. Beyond the changes in immune cells, they looked at changes in free fatty acids in obese patients’ blood as contributing to increased meta-inflammation.
Taken together along with other mechanisms connecting obesity and COVID 19 risk, we can see why some countries may have fared worse than others with COVID 19. We can also see why the infectious disease itself is not always the primary factor in whether someone suffers and dies or resists and overcomes a bacteria or virus. Optimizing our immune systems BEFORE the attacker knocks at our immune barriers is critical if we are to beat COVID 19 or any other infection. Prepping for 2020 and beyond must start now with our lifestyle and daily habits.
Gabrielle P Huizinga, Benjamin H Singer, Kanakadurga Singer. The Collision of Meta-Inflammation and SARS-CoV-2 Pandemic Infection. Endocrinology, 2020; DOI: 10.1210/endocr/bqaa154
Thanks to Science Daily:
The Endocrine Society. “Obesity may alter immune system response to COVID-19.” ScienceDaily. ScienceDaily, 3 September 2020. <www.sciencedaily.com/releases/2020/09/200903105602.htm>
Williamson, E. J. et al. OpenSAFELY: factors associated with COVID-19 death in 17 million patients. Nature, doi:10.1038/s41586-020-2521-4 (2020).
Zhu, L. et al. Association of Blood Glucose Control and Outcomes in Patients with COVID-19 and Pre-existing Type 2 Diabetes. Cell Metab 31, 1068-1077 e1063, doi:10.1016/j.cmet.2020.04.021 (2020).
Moser, J. S. et al. Underweight, overweight, and obesity as independent risk factors for hospitalization in adults and children from influenza and other respiratory viruses. Influenza Other Respir Viruses 13, 3-9, doi:10.1111/irv.12618 (2019).
Neidich, S. D. et al. Increased risk of influenza among vaccinated adults who are obese. Int J Obes (Lond) 41, 1324-1330, doi:10.1038/ijo.2017.131 (2017).
This content was originally published here.