A
Coronavirus Covid- 19
Welcome to Medical Minutes, I am Dr Craig Primack. Today is the beginning
of July 2020, this information is accurate as to what we know today. It may
change tomorrow or time may pass and we solidify some of these ideas or
completely dispute some or all of them. This medical minutes has been in
“working mode” for at least a month. I finally sat down the end of last week to
compile all my thoughts and expect todays medical minutes to be a bit longer
than usual. Let me know what you think…
We are in the midst of the worst infectious pandemic of at least the last 100
years. Recently in Arizona, where I live and practice, we have had daily and
weekly record numbers of people infected with the infectious agent SARSCoV2,
a coronavirus, that causes Covid-19, the disease.
My medical practice for the last 14 years has been full time weight loss or
medical obesity management, a field now called obesity medicine. I have been
a diplomate of the American Board of Obesity Medicine since 2012 when it was
established.
Obesity is a Disease
What we have learned, as doctors, is that Obesity is a disease. A disease of
too much body fat that leads to a multitude of related health problems that we
are all too familiar with . Obesity, unfortunately, also gives a higher risk of
developing severe symptoms and complications of covid19, even independent
of having other illnesses like heart disease, diabetes and high blood pressure.
The CDC now lists severe obesity (BMI >40) as a risk factor for severe covid-19.
However, it is not entirely clear why obesity is associated with a more dangerous
form of the disease but I hope to summarize some of the leading theories out
right now.
Corona Risk Factors
The other 2 major risk factors besides obesity that are at the top of the risk list:
older age (>60) and male sex. On the next tier is heart disease and diabetes.
Here are some statistics:
1. in China, where the outbreak began, data from 383 patents showed obesity
was associated with a 142% higher risk of developing pneumonia associated
with covid-19
2. In Seattle, a study of critically ill patients with covid-19 made similar findings.
This analysis found that 85% of the patients with obesity required
mechanical ventilation compared to 64% without obesity. Moreover, 62% of
the patients with obesity died compared to just 36% of those without
obesity.
3. In one of the biggest studies I found which looked at 428,000 people
infected with covid-19, 340 people needed hospitalization of which 44%
were overweight and 34% had obesity (77% of those hospitalized)
4. In another study that looked at 12 million electronic charts, among 5,683
patients who died, 29% were overweight and 33% had obesity (62% died
had either overweight or obesity)
5. Last in one report from Italy, 99% of deaths occurred in patients with six
diseases: obesity, hypertension, type2 DM, heart disease, kidney disease
and cancer.
So, Why is it?
Why does Obesity increase the risk of severe Covid-19?
First we know that the progression of covid-19 is largely dependent on the initial
health of an individual and the immune response triggered by the infection. In
the incubation phase, the patient does not present with severe symptoms.
Although, its in this stage that they may be mostly asymptomatic, but it’s also
when they are contagious and can spread the infection. If their immune
response is impaired or inadequate, the virus will multiply and destroy affected
cells, especially in organs that have a high expression of Angiotensin Converting
Enzyme 2 (ACE2) cells. ACE2 is a transmembrane protein and is the main entry
point into the body for many coronaviruses. In the lungs, an area with a lot of
ACE2 cells, these damaged cells induce inflammation in the lungs and this leads
to the classic symptoms of fever, cough, pneumonia and such. Its this
inflammation of the lungs, this severe inflammation, that is the main cause of the
life threatening disorders associated with covid19.
Why is Corona so Dangerous?
There are many hypothesis and plausible explanations that explain more of what
is going on:
1. One of the most straightforward explanations is that patients with obesity
have increased risk because of the mechanical weight in their abdominal
cavity and the diaphragm as well as on the chest wall. That they have a
higher resistance in their airways, lower lung volumes and weaker respiratory
muscles that are critical in the protection against pneumonia. These factors
make the individual more likely to develop pneumonia and they place
additional stress on the heart. In addition, associated diseases like
diabetes, heart disease and kidney disease along with high blood pressure,
high cholesterol and pre-diabetes can make people more susceptible to
infections (in general).
Chronic Inflammatory State from Obesity
2. Obesity, itself, is a chronic inflammatory state. Many years ago we believed
our fat (adipose tissue) was just an energy storage organ. Calories came in,
stayed there and were called upon when needed…like a gas tank. Boy, was
that wrong. Our fat is really a tremendous endocrine organ which
communicates with numerous parts of the body via hormones and cytokines
(inflammatory proteins) in the blood. Our adipose tissue (our fat) is part of
the immune system and also the metabolic system whereas through
hormones like leptin, it signals the status of our energy stores.
Adiposopathy
One of the
dysfunctions of our fat associated with this disease of obesity is called
adposopathy or “sick fat” With “sick fat” the fat sends out many different
inflammatory cytokines to the body that worsen or even cause many of the
associated diseases of obesity. Next, specifically with coronavirus, is the fact that
ACE2, the enzyme which the coronavirus uses to penetrate into the cell, is
more common in people with obesity. This enzyme is found in many parts
of the body but the lungs are a primary place and fat cells themselves
express ACE2 at fairly high levels. It has been noticed in the past with other
respiratory viruses, because of the high ACE2 level, that the viruses can
attack fat, they may last longer in fat cells and shed more slowly from fat
cells.
3. We see prolonged viral shedding and increased cytokine activation from
adipose tissue that has already been inflamed (adiposopathy) in people with
obesity. This is considered a “pre-activated” state where the body is already
sending out inflammatory signals to the body. This engine is already primed
and doesn’t need a lot of stimulation to just make more. This, unfortunately,
makes fat a good target organ for further immune amplification from
pathogens such as viruses. This has been seen with other viruses such as
H1N1 type A influenza, adenovirus 36, cytomegalovirus and HIV. In the
common yearly influenza, the flu, this same pathway significantly prolongs
the duration of viral shedding in humans with obesity. Some of the
inflammatory cytokines that we see here are tumor necrosis factor alpha
(TNF-Alpha), interleukin 1 (IL-1)and interleukin 6 (IL6). All 3 are involved in
the condition that many of you have now heard called “cytokine storm” or
properly “cytokine storm syndrome”.
Ace-2 Receptors
Specifically in the lung, there is a
delicate balance of pro and anti-inflammatory cytokines and this resultant
cytokine storm, significantly disrupts this homeostasis or balance, leading to
the lung disorders that lie at the heart of the deaths from coronavirus. The
cytokine storm overwhelms the immune system about 7-10 days into the
disease making the clinical course significantly worse. Along these lines,
inhibition of Intelukin-6 has already been proposed as a treatment in covid19
and the results of studies of one of the drugs that inhibit it, tocilzumab, are
undergoing.
*First, I want to tell you Not all hope is lost. What can we do?
First and most important, one thing that all of us can do at a minimum is wear a
mask and practice good social distancing.
Second, If you do have obesity or overweight, start or find a program from a
experienced medical professional who will customize a comprehensive medical
weight loss program for you that focuses on the four important aspects of
obesity treatment 1) nutrition 2) activity 3) behavior 4) medications. If you have
been unsuccessful in losing weight in the past, I do not think you want to redo
whichever way didn’t work for you in the past. Do you?
Last, possibly, we can protect ourselves against the covid-19 cytokine storm by
having a high level of cardiorespiratory (cardio) fitness induced by exercise
training, especially moderate intensity aerobic training, which may give us some
innate immune protection.
Exercise is a treatment
Exercise elicits potent and wide-ranging effects on the immune system, mostly
which are anti-inflammatory. We know exercise protects against several
chronic metabolic diseases including insulin resistance, associated with
diabetes, and often helps in the treatment of obesity.
Importantly, Exercise also improves immune responses to vaccination, and improves various
immune markers in diseases such as cancer, HIV, heart disease, diabetes,
cognitive impairment, like Alzheimer’s, and obesity. Furthermore, exercise
training may reduce the risk, length and severity of viral infections.
Thus at least hypothetically in humans, but proven well in mice, exercise may
counteract, at least partially the detrimental effects of the binding of the
coronavirus to the ACE2 receptor, reducing the inflammatory response in the
lungs.
To Summarize:
1) We are in the midst of the worst infectious pandemic of at least the last 100
years. we have had daily and weekly record numbers of people infected
with SARS-CoV2, a coronavirus, that causes Covid-19, the disease.
2) The CDC now lists severe obesity as a risk factor for severe covid-19 along
with age >60 and being male
4. Specifically with coronavirus, is the fact that ACE2, the enzyme which the
coronavirus uses to enter into the cell, is more common in people with
obesity both in the lungs and in the fat cells.
5. Best things we can do are 3:
1. at a minimum is wear a mask and practice good social distancing.
2. start a program from a experienced medical professional who will
customize a comprehensive medical weight loss program for you that
focuses on the four important aspects of obesity treatment 1) nutrition 2)
activity 3) behavior 4) medications. If you do not live in Arizona or do not
want to travel here…you may find a list of these professionals via the
clinician finder at www.obesitymedicine.org or my website at
scottsdaleweightloss.com
3. Cegin a cardio-focused fitness program, aiming for moderate intensity
aerobic training, which may give us some innate immune protection.
On the website under the video link, I will have several other links to a BMI
calculator, the clinician finder and exercise program called the couch to 5 k
which is a good place to get started in moving if you are currently inactive.
Thanks for watching.
Bibliography (in no particular order):
1. Increased ACE2 in Overweight COPD patients by Dr Andrew Higham doi:
10.1002/boy.22907
2. Obesity’s Role in Covid-19 Deaths: Big Food, Slow Government to Blame?
By Shelly Wood june 11, 2020 accessed on 6-24-2020 www.tctmd.com/
news/ibesitys-role-covid-19-dieaths-big…
3. Obesity a major risk factor for covid-19 hospitalization by Katie Pearce.
hub.jhu.edu
4. Latest evidence on obesity and covid-19. www.medicalnewstoday.com
access 6-24-2020
5. Is Adipose Tissue a Reservoid for Viral Spread, Immune Activation, and
Cytokine Amplification in Coronavirus Disease 2019? Paul Ryan et al.
www.obesityjournal.org Vo;28, Noumber 7, July 2020
6. Targeting the Adipose Tissue in COVID-19 Alexis Malavazos et al.
www.obesityjournal.org Vol 28 Number 7, July 2020
7. Does High Cardiorespiratory Fitness confer some protection against proinflammatory
responses after infection by SARS-CoV-2? Herman Zbinden-
Foncea et at. doi:10.1002/oby.22849
Links from the video:
2) www.ScottsdaleWeightLoss.com
3) https://www.cdc.gov/healthyweight/assessing/bmi/adult_bmi/english_bmi_calculator/bmi_calculator.html
