Insulin Does Not Increase Muscle Protein Synthesis Rate

Michael Scally MD

Doctor of Medicine
Trommelen J, Groen B, Hamer H, de Groot LCPGM, van Loon LJ. MECHANISMS IN ENDOCRINOLOGY: Exogenous insulin does not increase muscle protein synthesis rate when administrated systemically: a systematic review. European Journal of Endocrinology. http://eje-online.org/content/early/2015/02/02/EJE-14-0902.abstract

Background: Though it is well appreciated that insulin plays an important role in regulating muscle protein metabolism, there is much discrepancy in the literature on the capacity of exogenous insulin administration to increase muscle protein synthesis rates in vivo in humans.

Objective: To assess whether exogenous insulin administration increases muscle protein synthesis rates in young and older adults.

Design: A systematic review of clinical trials was performed and the presence or absence of an increase in muscle protein synthesis rate was reported for each individual study arm.

In a stepwise manner, multiple models where constructed that excluded study arms based on the following conditions:
model 1) concurrent hyperaminoamino-acidemia,
model 2) insulin-induced hypoaminoacidemia,
model 3) supraphysiological insulin concentrations, and
model 4) older, more insulin resistant, subjects.

Conclusions: From the presented data in the current systematic review, we conclude that
1) exogenous insulin and amino acid administration effectively increase muscle protein synthesis, however this effect is attributed to the hyperaminoacidemia,
2) exogenous insulin administrated systemically induces hypoaminoacidemia which obviates any insulin-stimulatory effect on muscle protein synthesis,
3) exogenous insulin resulting in supraphysiological insulin levels exceeding 50,000 pmol/L may effectively augment muscle protein synthesis,
4) exogenous insulin may have a diminished effect on muscle protein synthesis in older adults due to age related anabolic resistance, and
5) exogenous insulin administrated systemically does not increase muscle protein synthesis in healthy, young adults.
 
What about spiking endogenous insulin post workout in combination with hyperaminoacidemia? I was under the impression that this is the best method to promote muscle protein synthesis.
 

Dr JIM

Member
Excellent review article DOC, yet in spite of this form of evidence it seems everyday someone prances onto Meso boasting about how much they benefited by adding insulin to their cycle.

Is insulin needed for appropriate levels of anabolism?

You better believe it is, how many IDDM BB do you know? Essentially none, IME

Thus the addition of insulin above and beyond that which a normal pancreas produces does not promote anabolism and this article clearly emphasizes that point.
 
Last edited:
Excellent review article DOC, yet in spite of this form of evidence it seems everyday someone prances onto Meso boasting about how much they benefited by adding insulin to their cycle.

Is insulin needed for appropriate levels of anabolism?

You better believe it is, how many IDDM BB do you know? Essentially none, IME

Thus the addition of insulin above and beyond that which a normal pancreas produces does not promote anabolism and this article clearly emphasizes that point.

Well said man and I cannot argue with any of your points. Excellent post and also an excellent read on the article. Thanks for the helpful posts.
 

zoot494

Member
Well, technically yes... Insulin does not itself increase muscle protein synthesis, but that's not to say that adding insulin into your current cycle along with the proper diet will not yield greater results. Even the study you cited flat out says that insulin along with hyperaminoamino-acidemia provided grounds for increased muscle protein synthesis.

So yes, insulin alone = nothing

Insulin in a cycle + proper nutrition = definitely better results.
 

Dr JIM

Member
Well as I mentioned at the outset of this thread there is someone arriving every day who touts the benefit of insulin IN SPITE OF THE EVIDENCE .

The article clearly states only SUPRAPHYSIOLOGIC levels of insulin MAY promote protein synthesis.

The amount of insulin required and the duration of exposure was not specifically mentioned.

Moreover chances are these SP levels will also increase the side effects of insulin use, hypoglycemia in particular.

Since the normal insulin production ranges considerably but for the average 70 Kg male on a 2000kal diet about 30 units is secreted.

So how much MORE would be "required" to promote protein synthesis 50 or perhaps 100 units?

I don't really know but those whom embark on that path are ASKING for complications.

The possible exception may be PRO BB whom are being CLOSELY FOLLOWED by a DOC very familiar with the
use of insulin as a means of enhancing protein synthesis.

Goodness just let the pancreas do what it's intended to do, make insulin!
 
Last edited:

zoot494

Member
I'm not advocating nor do I use slin as I'm not a fan of potentially killing myself, however, you really can't deny that most people who use slin are taking supraphysiological doses. Same thing for people that take straight up test. The overwhelming majority are on much higher doses than TRT.

The article itself states that slin paired with aminos can and will increase muscle protein synthesis. Slin by itself won't. Slin *can* provide muscle growth benefits assuming you know when and how to dose it with a proper diet. That's undeniable. Literally their first 4 points were about how slin can increase muscle protein synthesis. Slin itself may not cause an increase, however, its effects on metabolic pathways provide an environment for increased muscle synthesis. This is literally fact. Whether you believe that slin is worth it is a personal decision everyone has to make for themselves. I've seen kids put themselves in a diabetic coma from improper use.


http://www.ncbi.nlm.nih.gov/pubmed/21864752

Here you go. "Insulin can be considered an anabolic hormone". Straight up due to its effects on your body. It creates an environment which can most definitely help. There is a fine line, however, and that must be tread on carefully.
 
Last edited:

Dr JIM

Member
You obviously don't understand what the article suggests and is studying.

SUPPLEMENTAL doses of INSULIN does not increase protein synthesis but INSULIN does mobilize AAs from the extra-vascular space to the intercellular space.

However SUPPLEMENTAL doses
of Insulin does not ENHANCE this process, bc a nl pancreas is DESIGNED for that very purpose already.

The ONLY mates I know of whom believe insulin is "necessary" are those using very high doses of GH but again the literature does not support this practice either.

IME those who use insulin are almost always making attempts at being noticed bc they have become proficient at parroting others whom "believe" insulin is beneficial.

It's unfortunate bc the literature, and there is well over 50 YEARS of controlled medical trials, simply does not support insulin supplementation to enhance PS above and beyond what a normal pancreas accomplished every day.

It's also ironic how some BB seem to understand the negative feedback mechanisms of some hormonal systems yet when it comes to insulin, the same physiologic processes feedback responsible for metabolic homeostasis are thrown out the window thereby justifying it's use.

Really what do you think happens to natural insulin secretion when supplemented?

Also another factoid many insulin users fail to realize is insulin by it's very nature enhances lipogemesis and may actually REDUCE LBM!

Additionally excessive levels of insulin are associated with insulin resistance, the latter being well documented as a type II DM risk factor.

I could go on about why insulin should NOT be used as a PED, but for some their gym "experience" dictates otherwise.

Jim
 
I'm not advocating nor do I use slin as I'm not a fan of potentially killing myself, however, you really can't deny that most people who use slin are taking supraphysiological doses. Same thing for people that take straight up test. The overwhelming majority are on much higher doses than TRT.

The article itself states that slin paired with aminos can and will increase muscle protein synthesis. Slin by itself won't. Slin *can* provide muscle growth benefits assuming you know when and how to dose it with a proper diet. That's undeniable. Literally their first 4 points were about how slin can increase muscle protein synthesis. Slin itself may not cause an increase, however, its effects on metabolic pathways provide an environment for increased muscle synthesis. This is literally fact. Whether you believe that slin is worth it is a personal decision everyone has to make for themselves. I've seen kids put themselves in a diabetic coma from improper use.


http://www.ncbi.nlm.nih.gov/pubmed/21864752

Here you go. "Insulin can be considered an anabolic hormone". Straight up due to its effects on your body. It creates an environment which can most definitely help. There is a fine line, however, and that must be tread on carefully.

If you read the points it says insulin and amino acids increase protein synthesis but this was attributed to the amino acids and not insulin itself.
 

Dr JIM

Member
Oh I've seen posts of guys "pinning" 2-5 units of slim every day to aid protein synthesis.

Yet when I read comments of that nature it's obvious someone is looking for someone else to query something like; gosh dude tell me more,,,,,,, bla bla bla!

People whom are doing this are only exposing their ignorance (and it must be vast based on statements of that nature) and how unfamiliar they are with evidence based research.

It's analogous to saying I pin 10 MGs of TT QD to enhance protein synthesis.

Right in both instances the amount used is just enough to lubricate that syringe :)
 

zoot494

Member
I don't think you bothered to read my posts...

I flat out said supraphysiological. I really have no idea how else to word it for you to understand what I'm saying.

I AGREE WITH YOU THAT SUPPLEMENTING NATURAL LEVELS OF INSULIN IS NOT BENEFICIAL. It's equivalent to supplementing TRT levels of test. I've already stated this. I flat out said that the benefits of insulin are undeniable and that supraphysiological doses WILL provide benefits. Same goes for literally any hormone.

You shut down your natural production in order to put levels in your body that cannot be achieved naturally. That is what this entire game is about. Being more than natural.

Putting natural levels of insulin into your body is absurdly stupid and shouldn't even be part of this conversation. If you want to discuss insulin injections then at least make it a reasonable discussion about higher than natural levels.

I've already stated that I don't use insulin nor do I tell others to, because in my opinion the risks and sides of elevated insulin levels are not worth it. It's a personal decision though, and to say that insulin does nothing is equivalent to rejecting science.

What you're arguing right now can be applied to healthy people taking TRT.
You're shutting down natural production for no reason. You're not getting any benefits as you still have the same overall levels of test, regardless of whether it is exogenous or endogenous. There's no point in doing it.
 
Last edited:

Dr JIM

Member
Yea but there is no evidence exceeding natural insulin levels induces protein anabolism UNLIKE other hormones specifically produced for GROWTH.

The fact is insulin has MANY more metabolic effects exclusive of PS unlike TT and GH.

But I'm done trying believe what you like.
 

Dr JIM

Member
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2843438/


there you go. Supraphysiological levels of insulin specifically for the purpose of inducing anabolism. While this study was done with older adults who are more insulin resistant, I think this gets the point across fairly well.

Anabolism can indeed be induced by insulin.

So let's pull a study on DIABETIC patients whom already have reduced insulin production and/or insulin resistance and most certainly do NOT have a normal pancreas to prove that what I said from the outset, insulin is needed for normal protein anabolism, ah duh!

But you had to locate a study the results of which have been known for decades to prove yet after only 8 posts your the man, right.

Well I'm in awe, yet will waste no more time with some uneducated and unread noob whose experience is so vast they came to Meso to set the record straight, lmao!
 
Last edited:

zoot494

Member
Yup, post count equals intelligence. Oh please, I've been around these forums for years. My first account wasn't on this website and I saw no reason to ever create an account for the past 4 years. If you want you can go look me up on other sites and see I joined early 2012/late 2011 if that pleases your internet ego.

You are so smart that you attack the man instead of his argument. You are so smart that you can't even fight against my argument, you simply resort to attacking me because this account is new. Good job. You definitely won this debate. You used 0 articles, 0 science, and a bunch of attacks. I dub thee winner.

You said that there were no studies done and no evidence for supraphysiological levels. I proved you wrong. I've proven you wrong every step of the way.

You can call yourself a doctor all you want, but you're far from one. You ignore science because of your own biased views. You haven't provided a single shred of evidence for anything you've claimed, while I have provided scientific evidence for everything I've said. Please, stop stroking your ego.

You have also made no real argument in any of your posts and instead choose to ramble on incoherently about random pancreas ideas that you have. I've made my stance. Insulin can induce anabolism. It's a simple fact.

What's your argument? That a pancrease produces insulin? No shit. Insulin supplementation isn't necessary? No shit. Nothing is necessary.

Does that mean that because it's not necessary that it isn't helpful? No. Science has proved it time and time again that it can be beneficial if done properly. If it isn't done properly then there are sever consequences, and nobody here is denying that.

Get the test out of your head and stop raging for 5 minutes. That may be long enough for you to read one scientific journal.
 
Last edited:
Interesting study & discussion, though I fear that an obvious benefit of insulin on cycle is being ignored.

Insulin is well known to reduce protein breakdown and can lead to a higher overall net protein balance - helping to increase muscle growth.
So though I wouldn't necessary call insulin "anabolic", it certainly warrants being labelled as an "anti-catabolic" hormone with clear benefits for its use on cycle - even if increase MPS is not one of them.
 

Dr JIM

Member
Interesting study & discussion, though I fear that an obvious benefit of insulin on cycle is being ignored.

Insulin is well known to reduce protein breakdown and can lead to a higher overall net protein balance - helping to increase muscle growth.
So though I wouldn't necessary call insulin "anabolic", it certainly warrants being labelled as an "anti-catabolic" hormone with clear benefits for its use on cycle - even if increase MPS is not one of them.

While that all sound good it's just not evidenced based.

Primarily bc most BB look at PS in a vacuum not understanding it's active in almost all cellular processes from enzyme synthesis
to somatic cell reproduction.

The bottom line considering the specificity of GH and AAS in SKM hypertrophy adding insulin to a cycle is like pissing in the wind, the only thing accomplished is reduced endogenous production.
 
While that all sound good it's just not evidenced based.

Their is plenty of data showing insulin to have the ability to inhibit protein breakdown - the question marks only surround the mechanisms behind this.
I recall theories surrounding the phosphorylation of PI3K/Akt or the downregulation of the ubiquitin-proteasome pathway to explain it but, last I checked, these were only theories.
Since there is no data on insulin reducing PS (that I'm aware of), and its well established that it inhibits PB, I don't see where the question mark is in regards to its potential role in aiding muscle hypertrophy.

If you were referring to something else not having evidence behind it, then I apologise in advance for the misunderstanding.
 

Sponsored Links

Latest posts

Top