BCMS Medical Record Fall 2020 - 14

Why Do Obese Patients Suffer Worse from COVID-19?
continued from page 13
evidenced in an early study of COVID-19 patients hospitalized near
the disease's origin in Wuhan, China11. Since elevated IL-6 levels
have been linked to respiratory dysfunction, it is likely that cytokines
like IL-6 in tandem with other effects of COVID-19 lead to the
pulmonary issues as mentioned previously12. According to Tower
Health endocrinologist Dr. Ilan Gabriely, "Obesity (and especially
abdominal obesity) is associated with more severe COVID-19
disease due to many factors including its cardiovascular effects, its
pro-inflammatory effects, and its pro-thrombotic effects. Diabetes
mellitus is associated with more severe COVID-19 disease due to its
chronic pro-inflammatory state. The combination of obesity (which
is relatively common, especially in type 2 diabetes) and diabetes
represents an ominous combination that may be responsible for
the increased morbidity and mortality from COVID-19 infection
in these patients." Given the state of low-grade inflammation obese
patients already have, the cytokine storm is more deadly in patients
with obesity and diabetes.

How COVID-19 Exacerbates Respiratory Issues
COVID-19 creates mechanical issues for obese patients, who
are typically difficult to intubate due to additional fatty tissue
surrounding the larynx6. The CDC has cited that one of the primary
reasons severely obese patients (BMI 40+) comprise a high-risk
group for COVID-19 complications is that they are more likely
to be afflicted with lung disorders such as acute respiratory distress
syndrome (ARDS); additionally,
obese patients are likely to suffer
from other chronic conditions13.
The aforementioned study from
Wuhan found notable outcomes
in patients with respiratory
conditions: Respiratory failure
(defined as when oxygen in the
blood is too low or carbon dioxide
in the blood is too high) was present in 54% of patients hospitalized
with COVID-19, afflicting 98% of non-survivors and 36% of
survivors; ARDS was found in 31% of patients, afflicting 93% of
non-survivors and 7% of survivors11.
Although ARDS was so prevalent in non-survivors, the low
overall incidence of ARDS points to a larger problem COVID-19
patients face-something that physicians had not anticipated. In the
early stages of the disease, the majority of COVID-19 pneumonia
patients present with an unusual variation of pneumonia scientists
have called Type L, for "Low elastance (i.e., high compliance),
Low ventilation to perfusion ratio, Low lung weight and Low
recruitability," which contrasts with what is expected in ARDS,
which scientists have called Type H for being "High" in the
categories where Type L was "low"14. Some of these characteristics
were not what physicians expected in hypoxic COVID 19 patients;
in Type L pneumonia, there is not much fluid in the lungs and
though air does not have a problem reaching the lungs, blood does14.
However, due to more fluid filling up the lungs over time, as well
as an uncontrollable cytokine storm, Type L pneumonia can evolve
14

|

www.berkscms.org

into the more deadly Type H pneumonia, which meets the criteria
for ARDS that physicians were expecting. These same mechanisms
that can lead to the death of non-obese patients are that much
more harmful to patients who suffer from obesity. Due to lower
lung compliance in Type H pneumonia, an obese patient's limited
coughing ability impedes the body's mechanisms for restoring the
normal balance of oxygen and carbon dioxide, making additional
medical issues like COVID-19 worse.

Comorbidities Such as Diabetes
Obesity and type 2 diabetes are so highly associated with
each other that they can be considered twin diseases. Eighty-nine
percent of American adults with diabetes are either overweight or
obese. The CDC estimated in 2018 that including diagnosed and
undiagnosed cases, 13% of American adults have diabetes and an
additional 34.5% have prediabetes15. Even before the COVID-19
pandemic, Berks County had high diabetes prevalences. This year
13% of Berks County adults have been diagnosed with diabetes as
compared to 11% in the state of Pennsylvania, which is higher than
the CDC's 2018 estimate of 10.2% of diagnosed adults nationwide4,
15
. If not controlled with medications or put into complete remission
by bariatric surgery type 2 diabetes, which accounts for more than
90% of diabetes cases15, it can lead to heart attacks, amputations,
blindness, and kidney failure, among other complications7.
According to Tower

Table 1: Inflammatory Markers Increasing with Diabetes and
COVID-1917, 18, 19. Levels of four selected inflammatory markers increase
modestly when the patient has diabetes but no COVID-19. All four of
these markers increase dramatically when the patient has COVID-19 but no
diabetes, and the inflammatory effect is compounded when the patient has
both diabetes and COVID-19.

Health infectious disease specialist Dr. Debra Powell, those who
have diabetes also suffer from poor circulation, impaired white blood
cell responses, and increased risk of all types of infection, further
predisposing them to worse COVID-19 disease outcomes.
Diabetes was also found to be prevalent in the aforementioned
Wuhan COVID-19 study, with 19% of total patients, 31% of
non-survivors, and 14% of survivors having this comorbidity as
compared to 11% of the general population11, 15. High HbA1c,
a marker of diabetes, has been found to predict the elevation of
many markers of inflammation, hypercoagulability, and mortality
in COVID-19 patients, so determining a COVID-19 patient's
HbA1c level upon entry to the hospital is useful in determining
http://www.berkscms.org
BCMS Medical Record Fall 2020

Table of Contents for the Digital Edition of BCMS Medical Record Fall 2020
