
Association of insulin resistance marker with severity and mortality of Covid-19 - sudoaza
https://cardiab.biomedcentral.com/articles/10.1186/s12933-020-01035-2
======
arkades
Please note:

The calculation of TyG is ln (fasting blood sugar) x triglycerides/2). Many
studies make the error of calculating it as (ln (FBS x TG))/2\. The only
online calculator I've found, I think, falls into the latter category, or has
worse errors - I didn't go through it too rigorously, but I put in values
beyond what human life can sustain and didn't get close to the cut-off for
this paper's bottom risk tier.

If you look at studies/calculator using the latter calculation, it looks like
this study looks at _really, really_ severe diabetics.

If you compare with the appropriate calculation, though, they're looking at
more run-of-the-mill "not optimally treated and obese" diabetics.

Hosseini 2017 did a paper analyzing a number of other TyG papers and
calculating results under both calculation methodologies, for context.

Please also note that this paper does not state _when_ the results were
collected. Insulin resistance/hyperglycemia is a symptom of sepsis - if these
labs were drawn on already-severe patients, it would be entirely unclear
whether they reflect a cause or an effect (or, as is almost certainly the
case, both!).

~~~
dreamcompiler
> The calculation of TyG is ln (fasting blood sugar) x triglycerides/2).

You have a extra right parenthesis, which makes it ambiguous. Do you mean

ln (FBS) x triglycerides/2

Or

ln (FBS x triglycerides/2)

?

~~~
tw000001
Doesn't matter since both multiplication and division are...commutative? Don't
remember the terminology but (10x2)/4 == 10x(2/4) == 5

~~~
rat9988
It matters here because he is using ln, and we don't know if we should stop at
the first right parenthesis or the second.

The word you are looking for is associative.

~~~
CydeWeys
Ooof, thanks for that. I didn't realize that was the natural log function
because of the space. My brain was parsing it as the word "In" and essentially
ignoring it.

~~~
pbhjpbhj
There shouldn't be a space IMO, reading it out of context I couldn't see what
the issue was either as I too was not parsing the ln as log_e.

    
    
        ln x
    

or

    
    
        ln(x)
    

but not

    
    
        ln (x)

------
subsubzero
Covid-19 is a very strange disease, it seems like it is amplified either way
(severe vs. non-severe) depending on health. This seems different from the flu
as the flu hits everyone very hard, the elderly/sickly especially hard. With
covid some people who have it, do not and will not have any symptoms which
cannot be said for the flu. I feel like the insulin marker data is an
albatross, having high TyG means alot of systems in your body are not doing
well, and the virus attacks weakness, it(covid-19) is also found to produce
extreme clotting so that is probably why people with diabetes/heart disease
and hypertension are all at high risk.

~~~
nradov
Asymptomatic infections are about as common with influenza as with SARS-CoV-2.

[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4586318/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4586318/)

Some influenza strains hit young, healthy patients harder than the elderly by
triggering a cytokine storm. This was particularly bad in the 1918 H1N1
pandemic.

[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4711683/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4711683/)

------
ashtonkem
I've suspected for a long time that Insulin resistance is going to be one of
the next big areas of focus for public health, but I thought that it was going
to happen the moment Apple finally figured out blood glucose measurement
through the skin. I did _not_ see a pandemic being part of it.

~~~
gumby
I love my Apple watch but I am astonished at your faith in their ability to do
noninvasive glucose measurement. People have broken their picks on that
particular coal face for decades.

For that matter DM2 is an area of quite active research (and, like diagnosis,
has been quite active for decades) as the financial payoff for any success is
enormous.

The only downside for transdermal diagnosis is the lack of consumables, which
makes it a tough market to enter and to be funded for. That _is_ an area
that's good for Apple as they are already selling the platform, so this would
be a feature that would add to sales. And one I'd use.

~~~
dreamcompiler
O2sat measurement has been noninvasive without consumables for a long time and
many phones can do it now. Why do consumables matter?

~~~
gumby
Investors don’t typically like diagnostics as the margins and volume tend to
be quite low. They also tend to be more “vitamin” than “aspirin”.*
Consumables, a least, give you recurring revenue and even in some cases the
opportunity for a razor-and-blades model.

You’d be surprised how many med products are designed specifically to require
consumables.

* (funny analogy to use in a med context)

------
49para
Insulin Resistance is the start of (all?) metabolic disease. So easy to
resolve using fasting, intermittent fasting, keto, carnivore etc diets.

Unfortuneately it slowly builds up over decades and only once disease has
progressed do Drs move on to treat the resultant disease (and mainly with
cholesterol lowering drugs).

Instead of measuring fasting glucose levels (which indicate diabetes), insulin
levels should be measured as they are the leading indicator.

~~~
conistonwater
> _So easy to resolve using fasting, intermittent fasting, keto, carnivore etc
> diets._

Or, you know, you could resolve it by eating a balanced diet too.

~~~
dghughes
On my mother's side of the family they were practically vegetarian or normal
as it was called back then. Vegetables all week and maybe on Sunday a roast
probably fowl of some sort.

This was during the 1940s. There were nine children and the parents on a farm
in a small rural area. So no extravagant purchases no pop, candy, etc. My mom
told me one Christmas her present was an apple and she was excited! The apple
came from the tree out back.

Sounds good? But all the women (grandmother and aunts) in the family developed
diabetes, one male (uncle) too.

Type 2 diabetes isn't always due to a poor diet.

~~~
49para
All carbohydrates become sugar, sugar elevates insulin, constantly elevated
insulin leads to diabetes.

I'm not sure all the causes of Type 2 diabetes but I would wager that the
current epidemic of Type 2 Diabetes is caused by too much sugar.

~~~
conistonwater
It is not currently established what the exact relationship is between sugar
in your diet, obesity, diabetes. They are all basically risk factors for the
next one, but they definitely don't _cause_ (in the strict scientific meaning
of the term) one another---there is nowhere near enough scientific evidence
that would support that. There's enough uncertainty about the whole process
that saying "avoid known risk factors" is about the best advice you can get.

------
danans
Given that insulin resistance is strongly correlated with obesity [1], I'm
surprised that wasn't a factor they controlled for, especially since the
respiratory difficulties associated with obesity seem to be a significant risk
factor for death with Covid19 cases.

1\. [https://obesitymedicine.org/obesity-and-insulin-
resistance/](https://obesitymedicine.org/obesity-and-insulin-resistance/)

------
shakil
Lets not confuse correlation with causation. All this study shows is people
with insulin resistance are at significant risk of dying from Covid, it
doesn't identify what actually kills them. However, if you look at the role
Vitamin D plays [1] in suppressing cytokine storms, which is what actually
pushes over an organism to the point beyond recovery from Covid, and then
understand that Vitamin D deficiency is common [2] in Type 2 diabetes, you can
begin to understand the fuller picture.

1\.
[https://www.medrxiv.org/content/10.1101/2020.04.08.20058578v...](https://www.medrxiv.org/content/10.1101/2020.04.08.20058578v4)
2\.
[https://pubmed.ncbi.nlm.nih.gov/26375925/](https://pubmed.ncbi.nlm.nih.gov/26375925/)

------
hirundo
"[triglyceride and glucose] index was closely associated with the severity and
morbidity in COVID-19"

So perhaps part of the reason why COVID-19 morbidity is lower in
Japan/Korea/Taiwan compared to the U.S. is due to lower prevalence of
metabolic syndrome. I wonder if that's also true for Europe.

~~~
arkades
> It suggests a protective effect of a keto/paleo diet.

No, if it can be taken at face value, it suggests a protective effect of a
healthy lifestyle.

~~~
floatingatoll
If taken at face value, it suggests a protective effect of low insulin
resistance as measured by the TyG marker. Everything else is interpretations
and chains of logical reasoning.

Neither of you are particularly wrong necessarily, but a third option is that
someone could be sedentary and eating carbs every day and have low TyG. It's
common to state that "activity XYZ will provide action-at-a-distance medical
benefit ABC" because stating accurately what's going on takes more words that
sound less certain:

"Paleo and keto diets may weaken Covid-19 by lowering insulin resistance"

"A healthy lifestyle may weaken Covid-19 by lowering insulin resistance"

But it's really worth saying it like this, even though few do. (And yes, these
aren't 'maybe' enough, but they're an improvement.)

~~~
arkades
You replaced the word "suggests" with "may".

You're seeing a distinction between these two words that I apparently do not,
since I take them both to indicate "this is a possibility, though not the only
one, and a far from proven certainty."

I would add that, even there, my statement was predicated on making an
inference about dietary habits - something I cast doubt on with the opening,
"if taken at face value." Something I further opined on in my other post,
where I pointed out that the paper may be reversing causality.

I feel like you're criticizing a strong inference having been made, that I
think pretty clearly wasn't.

