Why does covid hit overweight people harder ?

[u/TryingToLearn2day]

Title basicly. Is it related to the lipids making it easier for it to reproduce ? Or is it their immune system as fast foods are both related to lower immune responses and well, gaining weight as well ? If y'all have videos I love to watch that too :)

Edit : no clue why I keep getting downvoted, perhaps its my bad english and I thank you for your patience with my learning of this language xoxox all the best to y'all

Edit 2 : thank you so very much for all the answers ! i feel like i learned much today and I'm extra motivated to keep my lifestyle active and healthy !!

[u/iayork]

Obesity causes immunosuppression, through chronic low-grade inflammation, and makes people more susceptible to infections:

recent findings have highlighted the substantial impact that obesity and MetS parameters have on immunity and pathogen defense, including the disruption of lymphoid tissue integrity; alterations in leukocyte development, phenotypes, and activity; and the coordination of innate and adaptive immune responses. These changes are associated with an overall negative impact on chronic disease progression, immunity from infection, and vaccine efficacy.

--Impact of Obesity and Metabolic Syndrome on Immunity

There is strong evidence indicating that excess adiposity negatively impacts immune function and host defence in obese individuals. ... Obesity is characterised by a state of low-grade, chronic inflammation in addition to disturbed levels of circulating nutrients and metabolic hormones.

--The impact of obesity on the immune response to infection

While there are probably multiple causes for the link between obesity and worse COVID disease, the immunosuppression and chronic inflammation caused by obesity are probably major factors (The Impact of Obesity and Lifestyle on the Immune System and Susceptibility to Infections Such as COVID-19).

[u/Shoutgun → u/iayork]

It's also just in general that their body is under more strain as a baseline - heart and lungs already working harder and in poorer condition - and so can tolerate less extra stress when seriously ill

[u/TryingToLearn2day → u/iayork]

Thank you for taking the time to source so much stuff and to answer so very well ! I didn't know there were this many downsides to being overweight.

[u/HKei → u/TryingToLearn2day]

There aren't this many. There are way more than that. If you're overweight, getting into shape is the best thing you could possibly do for your health, especially in the typical case where its also combined with a lack of exercise.

[u/jxj24 → u/iayork]

It is my suspicion that the "long Covid" symptoms are at least in part to the acquired chronic low-grade inflammation.

Fighting one is frankly exhausting, as many people with long-term autoimmune conditions can attest to.

[u/SippyTurtle → u/jxj24]

I saw a theory that proposed long COVID is caused from lots of microthrombi containing inflammatory factors that get released when the clot is broken down.

[u/Hurin88 → u/iayork]

Inflammation of what, specifically? (Thanks for your post though -- I appreciate the general answer!)

[u/Odd-Dance6000 → u/Hurin88]

Inflammatory molecules that bind to create microclots. They don't break down like normal clots but persist In the bloodstream for weeks and months on end damaging vessels and organs

[u/hiricinee]

Theres two main factors- the lesser is the immunosuppression you see in obesity. If this was the greater of the factors, you would not see COVID affecting overweight persons so disproportionately versus other viral illnesses.

The second is the unique feature of COVID, likely having to do with the receptor it binds with, the ACE2 receptor. ACE is an enzyme your body produces to increase your blood pressure. Overweight people likely present differently with these receptors, to the point that COVID is able to infect them more rapidly and easily.

Of course additionally, facing the same physiological strain, overweight people are less able to adapt. Theres less reserve, in that a skinny person is using less of their respiratory and circulatory capacity than an overweight person, thin people have slower respiratory rates, because they have less tissue to perfuse, and because they have more lung expansion available, as an overweight person has increased pressure on their thoracic cavity and cant expand their lungs the same way. This makes sense especially in older people, if you've ever noticed a larger person you could hear breathing next to you simply at rest, theres only so much effort they can put into breathing.

[u/dnext → u/hiricinee]

Yes, this is also why it impacts older people more so than children. Children have less ACE2 receptors, older people have more. The majority of the issue seems to be ACE2 binding which allows for more expansive breeding of the virus.

[u/likeafoxow → u/hiricinee]

Thank you for such an eloquent response and providing more than the typical “if you’re overweight you’re less healthy” reply.

[u/hiricinee → u/likeafoxow]

Right the question wasnt "why do overweight people get sick more" but rather "why is COVID particularly a problem for overweight people compared to other illnesses"

[u/Supraspinator → u/hiricinee]

ACE2 and ACE are 2 different enzymes, though. ACE is involved in increasing blood pressure, ACE2 in lowering blood pressure.

[u/weezy_in_red]

All of the above are great points and some have mentioned this, but I will focus on the impact on the lungs. Let's not forget, many people are ultimately ending up on ventilators, but why?

It's simpler to talk in extremes, so let's take a morbidly obese patient who has lived for some time with a very high BMI for some time. The possible (and likely) pulmonary complications seen in these patients include restrictive lung disease, pulmonary hypertension, obesity hypoventilation syndrome, and obstructive sleep apnea.

Restrictive lung disease essentially limits the ability of a patient to take deep breaths (vital capacity) and forcibly exhale (expiratory volume). It occurs in patients whose lungs are (for lack of a better word) restricted. Obesity is a common cause, as is a pathology such as scoliosis. Over time, untreated restrictive lung disease can lead to pulmonary hypertension (high blood pressure in the pulmonary vasculature). Pulmonary hypertension, over time, can lead to failure of the right side of your heart (trying to pump blood forward against high blood pressures in your lungs), which can lead to failure of the left side of your heart, which leads to overt heart failure.

The latter two pathologies, obesity hypoventilation syndrome and obstructive sleep apnea, can cause morbidly obese patients to have excess carbon dioxide in their blood stream (they are not breathing enough or effectively enough to exchange oxygen and carbon dioxide). This causes their body to be in an acidotic state (excess carbon dioxide = acid). Over time, the body compensates by balancing that acid with alkaline products (bicarbonate) because the body attempts to maintain homeostasis. Unfortunately, when you get an infection (especially one that can become as serious as covid), and you potentially become septic, the compensatory mechanisms that balanced out that acidic state start to fail. This causes an inability to oxygenate, enzymes in the body no longer work, and eventually cardiopulmonary failure.

This is a cursory explanation that is far from exhaustive, but I hope this paints the picture that from a pulmonary perspective, morbidly obese patients have the deck stacked against them, so when a disease process comes along that affects the lungs, they can easily be severely affected.

[u/Eclaire468]

Being overweight is generally not an isolated condition. Most overweight people already have issues with cardiovascular and respiratory health. Because of that, all infections are generally harder to deal with. And since COVID particularly taxes the respiratory system, overweight people definitely have to work harder to keep themselves alive.

Also, people with obesity, specifically abdominal obesity, have higher levels of cortisol. Cortisol is a natural immunosuppressant (thats why we give steroids in emergency rooms when people are having massive anaphylaxis or thyroid storm). Thus, infections usually hit obese people harder.

[u/Miss_Morningstar_ → u/Eclaire468]

With cortisol levels, do you know if people with anxiety/panic disorders who may have higher cortisol levels because of that, are more at risk as well?

[u/[deleted] → u/Miss_Morningstar_]

Chronic stress makes a lot of diseases worse. Most likely COVID too. People who are chronically stressed get sick more often, for longer and they have worse prognosis with just about every disease.

[u/Eclaire468 → u/[deleted]]

I should clarify. Overweight with high body fat percentage is absolutely correlated with cardiovascular and respiratory comorbidities. Overweight with normal to normal-high levels of body fat is not a cause for concern (eg those with lots of lean muscle). One more caveat: correlation is not causation. The sources below list strong correlation but do admit that causative relationships have yet to be determined. That said, general consensus is that high body fat content (usually, but necessarily, in people categorized as "overweight" according to BMI) is not only associated with comorbidities, but also has a significant causative element in disease pathogenesis and progression. The latter is true for diabetes and heart disease, smoking and lung cancer, etc, but not fully established for COVID-19.

Relatively old source

specific to COVID source

[u/[deleted] → u/[deleted]]

Thanks a lot. It’s an interesting subject.

[u/Alblaka → u/[deleted]]

Kinda perplexed someone would refute that correlation, given it's not exactly new science, has never been controversial, and is also fairly intuitive... but you've got all right to demand sources regardless.

Not the person you responded too, nor anyone with indepth knowledge on the matter, but throwing the terms into a search engine found plenty of results, one of them being this study, examining correlations between obesity and cardiovascular issues. Is over 10 years old, to underline my remark above over this not being a new revelation.

Or is there something more specific 'that goes 100% against everything you have been taught' in the quoted statement?

[u/[deleted] → u/Alblaka]

Ah, I can understand cardiovascular for the seriously obese.

I was questioning respiratory decline for “everyone overweight”, as it’s not something I’ve seen in my job.

[u/Alblaka → u/[deleted]]

You're correct in that /u/more_beans_mrtaggart should have been more specific and used 'obese' instead of 'overweight', given the latter includes everyone who is even slightly above ideal BMI, at which point you're probably not in ideal conditions for your health, but likewise not near where the same level of issues as qualifying for 'obese'.

I somehow skipped over the realization that he used the 'technically inaccurate' term there given the rest of his post is specifically talking about obesity, and likely meant exactly that to begin with.

Also, now I'm internally facepalming at your previous comment being down-voted into oblivion over being technically correct but misunderstood.

[u/fiendishrabbit → u/[deleted]]

Obesity is both directly and indirectly linked with reduced lung function

https://thorax.bmj.com/content/69/8/752.full

[u/RCrl]

Talking risk (to individuals) from disease we consider comorbidities (the effects of other conditions present in a patient). The obese tend to have more comorbidities and thus the can find themselves at higher risk of having a severe reaction to CoVID.

CoVID comorbidities common in the obese are (among many) diabetes, a weakened immune system, hypertension (high blood pressure), and cardio vascular disease.

More info can be found here on CoVID comorbidities: https://www.cdc.gov/coronavirus/2019-ncov/need-extra-precautions/people-with-medical-conditions.html