The Corona virus, or Severe Acute Respiratory Syndrome Coronavirus-2 (Sars-cov-2) as the real term is, is an RNA virus that causes the disease Covid-19 (Corona virus disease 2019). The current epidemic is the third with a coronavirus in the 21st century and by far the most severe.
Society, media, politics, health care and research are now fully focused on covid-19 and the virus Sars-cov-2. From the statistics updated daily from the Swedish Intensive Care Register we see that in Sweden 75% of those admitted to IVA with Coivid-19 are male, the median age is 61 years and 73.9% have a risk factor. Dominant risk factors in the registry are high blood pressure (34.9%), diabetes (25.3%), heart and lung disease (23.6%). Obesity is seen here only to be around 3% -but this is tricky, because the registry here reports only “extreme obesity”, i.e. BMI > 40, and we know that BMI well below 40 often results in high blood pressure, type 2 diabetes and cardiovascular disease (obesity is defined as BMI > 30).
Recent research studies
Furthermore, if you look more specifically for obesity versus Covid-19 (here you have to remember that this field of research is completely new and new studies are published all the time), then you will find a study from France (Simmonet et al). A hospital has studied 124 patients admitted to ICU due to Covid-19. 68.6% of these patients required respiratory care. Patients with BMI > 35 were more than 7 times more likely to need respiratory care compared to those with normal weight (regardless of age, diabetes or high blood pressure).
A recent study from New York (Petrilli et al) has followed more than 4,000 patients with Covid-19. Among other things, risk factors were analysed vs. a/ needing hospital treatment and b/ becoming “critically ill” (critical illness, defined as need for ICU care, discharge to hospice or death). The factors most strongly associated to the need for hospitalization were in descending order age > 75 years, age 65-74 years, BMI > 40, heart failure, BMI 30-40, age 55-64 years, chronic kidney disease, diabetes and male sex.
Risk factors for critical illness in Covid-19 were in descending order age > 75 years, age 65-74 years, BMI > 40 and BMI 30-40. (For those of you in health care: lab-wise CRP > 200, high D-dimer and oxygen saturation < 88% upon arrival at the health care department were the strongest factors related to the risk of developing critical illness).
Obesity as a risk factor in Covid-19
It seems, therefore, that obesity disease is a clear risk factor associated with Covid-19, perhaps BMI > 40 is the main risk factor after increasing age(?). This is something that needs to be researched more, but also highlighted better –the latter ASAP, as the epidemic is already in full swing.
SUPPLEMENT: On Friday, April 17, the National Board of Health and Welfare announced that obesity disease with BMI > 40 is an independent risk factor for Covid-19 disease, read the report here.
In depth reading on corona, ARDS and obesity
The following are things that we don’t know everything about yet, so they are hypotheses rather than proven facts. The research on this has not yet “caught up” with the situation we are in with the epidemic in society. But with this said, if you want to immerse yourself then this is for you: What distinguishes the coronavirus Sars-cov-2 from the common flu or cold virus is that it not only infects the upper respiratory tract (and causes a sore throat, etc.) but in some cases also infects deep into the lungs and at the far end of the alveoli. Here, this infection causes alveolar cells to be destroyed, but also gives a reaction from the body itself: our immune system reacts, sometimes even too much. This gives the risk of acute respiratory distress syndrome (ARDS). ARDS is caused by a hyperactive immune system, sometimes called cytokine storm. The body’s attempts to repair the damage result in fibrosis formation and worsened oxygen saturation. What distinguishes this from a common pneumonia is that the body itself exacerbates the problem because the immune system overreacts.
Where could obesity come into this? Well, research has shown that adipose tissue is much more than just an energy deposit, it is also a hormonally active organ. Fatty tissue produces, among other things, cytokines, hormones, growth factors and prostaglandins, which have effects on organs such as the liver, pancreas, muscles, kidneys, brain and immune system. Obesity has been shown to increase activation of pro-inflammatory substances released from adipose tissue (e.g. interleukins, interferon and TNF-alpha). Thus, many people with obesity have an incorrectly overactivated immune system already normally. If this affects the risk of getting ARDS from the corona virus, future research will show. Other factors that can come into play here are that we know that obesity can contribute to so-called increased coagulability (increased risk of blood clots), other concomitant obesity-related diseases, and the risk of ventilating one’s lungs less effectively at high BMI than at normal weight.
How much risk do you have?
How are we going to deal with all this new information? How “big risk” do you have if you are reading this and living with a large body? I understand if you worry, this is an epidemic that we are not used to.
What can probably be concluded from the study from New York above, is that the combination age >55 years at the same time as BMI > 30 increases the risk of needing hospital care at Covid-19, and that age > 65 years at the same time as BMI > 40 greatly increases the risk. Note that all “risk” is relative, each individual has his or her own unique conditions.
What can you do to reduce your risk?
Follow the recommendations of the authorities including social distancing, hand sanitizing, etc. A general recommendation if you are worried about Covid-19 and are in a probable risk group –test yourself. Hopefully, tests will become more available in Sweden now and people with obesity are very likely a risk group that should be prioritized. (In particular, it applies to those of you who have BMI > 40.) Try to work out even if you are at home -physical activity is positive for the immune system.
I have had bariatric surgery -is that an increased risk?
There is no indication that this in itself would increase the risk. Vitamin or mineral deficiency, on the other hand, is negative for the immune system – so take your vitamins after surgery!
If you need more support or have questions, please contact the National Association HOBS , they are there for you!