T Nation

Insulin Resistance


#1

What are the symptoms of insulin resistance?
Does it really affect your strength and hypertrophy gains due to the reduced insensitivity to muscle cells?
What causes insulin resistance?

Would greatly appreciate all opinions/feedback from you guys
Thanks(:


Preventing Diabetes
#2

You should be able to see insulin resistance in the mirror. Love handles


#3

[quote]Sweetcries wrote:
What are the symptoms of insulin resistance?
Does it really affect your strength and hypertrophy gains due to the reduced insensitivity to muscle cells?
What causes insulin resistance?

Would greatly appreciate all opinions/feedback from you guys
Thanks(:[/quote]

The first two questions are a little more difficult to answer. But, I will detail the first one for you.

The mechanism of insulin resistance is as such:

There are insulin receptors on a cell membrane, once insulin binds to an insulin receptor, endocytosis occurs where the insulin/insulin receptor complex is absorbed by the cell and the insulin hormone is degraded by lysosomes. Around 90% of the insulin receptors are recycled from this process and sent back to the cell membrane to continue the cycle.

The problem arises when insulin receptors are continuously saturated with the presence of insulin.

Lets use an arbitrary number of 100 for the number of insulin receptors on a given cell. If all 100 of those receptors are saturated and undergo endocytosis and 90% of those receptors are recycled that will leave 90 receptors on the cell membrane. If those 90 receptors are saturated and undergo endocytosis and 90% of those receptors are recycled that will leave 81 receptors. So on and so forth.

The reduction of insulin receptors is effectively what leads to insulin resistance. The body needs time to replenish insulin receptors and the way to do this is by an absence of insulin for a given amount of time.

There are autoimmune situations where antibodies attach to insulin receptors, rending them incapable of performing their function. This isn’t very common to my understanding. But, this would also result in a form of insulin resistance, essentially.


#4

[quote]Sweetcries wrote:
What are the symptoms of insulin resistance?
Does it really affect your strength and hypertrophy gains due to the reduced insensitivity to muscle cells?
What causes insulin resistance?

Would greatly appreciate all opinions/feedback from you guys
Thanks(:[/quote]

I will take a stab at question 2, also.

The way insulin resistance could effect strength and hypertrophy is via controlling the flow of glucose and amino acids into muscle cells. Insulin causes glucose and amino acid transport into cells via specific transport proteins. Of course, ample amounts of amino acids and glucose into muscle cells is what we all want, this would potentiate growth, repair, and fueling of muscles.

If insulin resistance is an issue, insulin is not going to be as effective in signalling the uptake of amino acids and glucose into muscle cells. If insulin resistance occurs to a significant enough degree in fat and muscle tissue, where say glucose uptake is impaired, this is essentially the fast track to Type 2 diabetes.


#5

@ Shanz: Thanks for those explanations. Insulin sensitivity/resistance is something I’ve read about a few times in various places but this makes it all much clearer.


#6

Let me add a little for discussion.

  1. you can have normal blood sugar but insulin resistance, during periods where the pancreas will produce large amounts of insulin to manage blood sugar despite the insulin resistance. This tends to lead to beta cell proliferation, but it can trigger other factors (possibly burnout and possibly autoimmune) that can eventually knock out the pancreas.

  2. You can have insulin resistance due to having more fat on your body and more circulating triglycerides and free fatty acids. High circulating triglycerides/ffas reduce the effectiveness of insulin and end up causing pancreatic over secretion and possible pathology. Also inflammation, (cortisol), adrenaline, adrenergic substances like ephedra reduce insulin sensitivity because they counter regulate insulin. They can lead to hypersecretion and eventual pathology. Sickness can lead to this.

  3. You can also have low carb induced insulin resistance called physiological insulin resistance. This is probably due to more fatty acids in the blood, and circulating ketones. (In part it may be that the pancreas becomes less responsive to blood sugar at that level. People on a near zero carb diet have been found to have fasting blood sugars of 115, and post glucose tolerance test blood sugars over 250 for over an hour, but if they eat carbs for 2 weeks, they have basically a normal glucose tolerance test. A glucose tolerance test is not valid if someone has not consumed at least 150 grams of carbs in each of the last 2 days, because it can result in a 1 or 2 hour failure with blood sugar over 140 at 2 hours.


#7

Some symptoms include high fasting blood sugar, high fasting insulin (>12 IU/dl). high post GTT blood sugar (150 at 1 or 2 hours), high post-prandial insulin levels A1C over 5.7

Also, acanthosis nigricans (dark marks in the folds of the neck or other areas. I believe that these are signs of hyperinsulinemia, not necessariliy insulin resistance, but insulin resistance basically results in high insulin output.


#8

[quote]mertdawg wrote:
Let me add a little for discussion.

  1. you can have normal blood sugar but insulin resistance, during periods where the pancreas will produce large amounts of insulin to manage blood sugar despite the insulin resistance. This tends to lead to beta cell proliferation, but it can trigger other factors (possibly burnout and possibly autoimmune) that can eventually knock out the pancreas.

  2. You can have insulin resistance due to having more fat on your body and more circulating triglycerides and free fatty acids. High circulating triglycerides/ffas reduce the effectiveness of insulin and end up causing pancreatic over secretion and possible pathology. Also inflammation, (cortisol), adrenaline, adrenergic substances like ephedra reduce insulin sensitivity because they counter regulate insulin. They can lead to hypersecretion and eventual pathology. Sickness can lead to this.

  3. You can also have low carb induced insulin resistance called physiological insulin resistance. This is probably due to more fatty acids in the blood, and circulating ketones. (In part it may be that the pancreas becomes less responsive to blood sugar at that level. People on a near zero carb diet have been found to have fasting blood sugars of 115, and post glucose tolerance test blood sugars over 250 for over an hour, but if they eat carbs for 2 weeks, they have basically a normal glucose tolerance test. A glucose tolerance test is not valid if someone has not consumed at least 150 grams of carbs in each of the last 2 days, because it can result in a 1 or 2 hour failure with blood sugar over 140 at 2 hours. [/quote]

These are great practical examples of how insulin resistance can develop. There are likely many more ways in which insulin resistance eventually develops, and likely many we do not even know about it yet.

I think it is important to point out that the basic concept remains: too much insulin --> over saturation of insulin receptors --> downregulation of insulin receptors --> insulin resistance.

As mertdawg pointed out though, there are many different ways to arrive in a state where an individual is producing too much insulin.


#9

Other than berberine/Indigo, I think one could safely restore insulin sensitivity with short but frequent bouts of training before meals: body weight training, sprints, walking if not pressed for time


#10

[quote]juverulez wrote:
Other than berberine/Indigo, I think one could safely restore insulin sensitivity with short but frequent bouts of training before meals: body weight training, sprints, walking if not pressed for time[/quote]

This is an interesting concept that has rolled around in my head before, too. I would love to see some research done on this. The theory of some amount of exercise before meals will induce non-insulin mediated glucose uptake, thus sparing the need for the usual amount of insulin to result in glucose uptake. This would theoretically lead to a replenishing of insulin receptors and improved or optimized insulin sensitivity.

The question is to how long or how intense of exercise is needed to stimulate GLUT 4 translocation for glucose uptake independent of insulin.


#11

[quote]PB Andy wrote:
You should be able to see insulin resistance in the mirror. Love handles[/quote]

Andy, are you saying that men who store excess fat in the love handles and don’t gain/lose equally across their whole body are showing signs of insulin resistance?

That may be worded like a “call out”, but it’s a genuine question. I ask because I’ve gotten pretty lean yet I still have love handles and a bit of lower ab fat. Three point caliper (Jackson/Pollack) puts me about 6% and Accu-Measure single-site put me between 6.7% & 9.2% according to their chart. (FTR, I don’t believe I am as lean as either show but I am pretty lean; planning on getting a DEXA scan soon.)

So if that would indicate to you I have some insulin resistance issues, do you genuinely think Indigo could help? FYI I’ve recently switched from a low-carb cut to a gain phase with a lot more carbs (ramping cals). Just wondering if now would be a good time to try it out.