Thursday, June 23, 2011

Let's talk about hormones! Part 2: Growth Hormone

So in the last post we talked a bit about Thyroid hormone and its function in the body.  This time, let's get into a hormone that's a little less well known but that plays an interesting role in anti-aging (among other things).  Human Growth Hormone (HGH) is a very complex hormone and we probably don't even know half of its functions.  We do know that it is a key factor in regulating growth in childhood and adolescence and but our understanding has expanded to it functions in healthy aging and tissue repair.

At the most basic level Growth Hormone influences how the body use fuel and how it grows and repairs, especially on the cellular level. If we think about HGH's primary goal is tissue growth and repair, then its effects on metabolism make a little more sense.  HGH signals to cells to take in more nutrients and also to make more energy sources available in the blood.  It increases the cells uptake of protein, which is key  for bone and cartilage production.  It also increases the release of fatty acids from adipose (fat) stores, so that those fats can be broken down and used as fuel.    HGH increases the liver's production of glucose as well as increasing insulin resistance, basically increasing overall blood sugar.  So much so that HGH could even be called a diabetic-like hormone.  Not only that, it signals for a release of ghrelin, which stimulates appetite!  No wonder teenager boys eat as much as they do. (1)

Its pretty obvious why HGH would be important for childhood growth and HGH does decrease about 14% with each passing decade.  Unfortunately, this decrease contributes to many complaints that we associate with aging.  These include: loss of muscle mass, strength and stamina, papery skin changes, poor circulation and depressed mood. (2).  In addition, we also suspect HGH plays a role in Fibromyalgia.  HGH output follows a daily rhythm, with its biggest output in the first few hours of sleep.  The current theory for Fibromyalgia is that there is sleep disturbance (usually stress or some type of injury), which decreases the HGH output. This  prevents the body from doing its daily repair and will perpetuate the body pain.

We can easily blood levels of HGH,  but this doesn't give us very usable information.  HGH varies so much during the day, that a single sample doesn't tell us anything about the overall picture.  Some labs will measure IGF-1, which is a different hormone but it rises and falls with overall HGH levels and ends up being a reasonable reflection of HGH levels.  Unfortunately, not all labs will test IGF-1 levels and it does end up being a slightly pricey test. (1).

So how to support HGH levels:  Direct hormone supplementation isn't usually recommended outside of some genetic growth disorders, so for antiaging and fibromyalgia we need to support it indirectly.  Exercise and Sleep are essential factors for supporting HGH production.  So the first and most important step is to address sleep concerns, with sleep hygiene and possibly relaxant/sedative herbs (passionflower and valerian) or other most direct supplementation support like melatonin or 5HTP.  Your Naturopathic Physician may also suggest specific herbs or amino acid formulas that will specifically increase HGH production and these should only be done with the supervision of a qualified and licensed professional. (1).

Good luck and keep an eye out for the next posting that will discuss Estrogen and Progesterone.  As always, please feel free to leave a comment or email if you have any questions or topics you'd like to see discussed.

References:
1) Lecture by Pamela Jeanne, ND.  HOrmonal Milieu in the Aging Process: A Naturopathic Perspective.  NW Naturopathic Physicians Conference. May 2011. Vancouver, BC.

2) Medscape: http://emedicine.medscape.com/article/120767-overview

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