Wanted to post this exchange with Dr. Lunn re: IGF-1 and GH.
From: Katharine Lunn
Sent: Friday, March 05, 2010 3:16 PM
To: Heather
Subject: Re: DCPAH results for 000943209 Heather
No - it's not the other way around - although that would seem more logical.
IGF-1 is a growth factor - it makes things grow - it is IGF-1 that causes the bones and tissues to grow. Athletes take growth hormone for those effects (more muscle). It is the GH that antagonises the insulin. IGF-1 is anabolic (builds things up) and GH is catabolic (breaks things down).
Does that make sense?
Kathy
On Mar 5, 2010, at 12:39 PM, Heather wrote:
I thought it was the other way around…I thought that the IGF-1 interfered with insulin usage and that the GH caused the tissue stuff? It makes sense to me that way…growth hormone causes growth…insulin-like growth factor screws with insulin.
Have I had it incorrect all this time? Please confirm so that I don’t keep saying it wrong and so that we can get our information updated.
Heather
From: Katharine Lunn
Sent: Friday, March 05, 2010 12:04 PM
To: Heather
Subject: Re: DCPAH results for 000943209 Heather
Yes - that has been noticed in other studies too. The IGF-1 is the hormone that causes the tissue effects of acromegaly. It is the GH that antagonises the insulin. So I expect that GH will be down. What we don't yet know is why IGF-1 stays high in some of these cats even though GH falls. I have seen IGF-1 fall eventually, so it may be a delayed effect.
It is not as simple as we would like!
I guess the bottom line is how the cats are doing and if their diabetes is doing better.
Kathy
On Mar 5, 2010, at 10:10 AM, Heather wrote:
Thank you for sending so quickly! Also, thank you for responding to Holly/Pablo so quickly about the SRS.
I sure don’t understand those results…Boo’s completely off insulin, yet the IGF-1 is the same! Milo’s was ½ what is was at 6 months, yet he’s never gone off insulin. I tested Boo’s BGs the other day and she was at 70, so she’s still doing well.
Will be interesting to see the GH.
From: Katharine Lunn
Sent: Friday, March 05, 2010 3:16 PM
To: Heather
Subject: Re: DCPAH results for 000943209 Heather
No - it's not the other way around - although that would seem more logical.
IGF-1 is a growth factor - it makes things grow - it is IGF-1 that causes the bones and tissues to grow. Athletes take growth hormone for those effects (more muscle). It is the GH that antagonises the insulin. IGF-1 is anabolic (builds things up) and GH is catabolic (breaks things down).
Does that make sense?
Kathy
On Mar 5, 2010, at 12:39 PM, Heather wrote:
I thought it was the other way around…I thought that the IGF-1 interfered with insulin usage and that the GH caused the tissue stuff? It makes sense to me that way…growth hormone causes growth…insulin-like growth factor screws with insulin.
Have I had it incorrect all this time? Please confirm so that I don’t keep saying it wrong and so that we can get our information updated.
Heather
From: Katharine Lunn
Sent: Friday, March 05, 2010 12:04 PM
To: Heather
Subject: Re: DCPAH results for 000943209 Heather
Yes - that has been noticed in other studies too. The IGF-1 is the hormone that causes the tissue effects of acromegaly. It is the GH that antagonises the insulin. So I expect that GH will be down. What we don't yet know is why IGF-1 stays high in some of these cats even though GH falls. I have seen IGF-1 fall eventually, so it may be a delayed effect.
It is not as simple as we would like!
I guess the bottom line is how the cats are doing and if their diabetes is doing better.
Kathy
On Mar 5, 2010, at 10:10 AM, Heather wrote:
Thank you for sending so quickly! Also, thank you for responding to Holly/Pablo so quickly about the SRS.
I sure don’t understand those results…Boo’s completely off insulin, yet the IGF-1 is the same! Milo’s was ½ what is was at 6 months, yet he’s never gone off insulin. I tested Boo’s BGs the other day and she was at 70, so she’s still doing well.
Will be interesting to see the GH.
