by Lena Edwards, MD, FAARM
The stress response is in place to allow us to survive hostile environments and adapt accordingly. It is when the stress response system (HPA Axis) is chronically stimulated that maladaptation and disease arise. Every organ system and hormone produced by the body is ultimately affected.
Prolonged stress inhibits the non-essential functions of growth and reproduction. Both Corticotropin releasing hormone (CRH) and cortisol inhibit the release of Growth Hormone, Thyrotropin releasing hormone (TRH), Thyroid stimulating hormone, and Gonadotropin releasing hormone (GnRH), all of which are required for the production of the anabolic steroid hormones. Since these hormones antagonize the effects of cortisol, their absence further potentiates the actions of the unopposed catabolic corticosteroids further impairing growth, repair, and reproductive functions. Furthermore, even if present in small amounts, the anabolic hormones Growth hormone, DHEA, and testosterone are unable to exert their physiologic effect because of target tissue insensitivity.
Stress induced GnRH deficiencies have been shown to cause delayed puberty, anovulation, and spontaneous abortion in women and decreased testosterone levels, impaired spermatogenesis, and decreased libido in men. In fact, stress induced abnormalities in cortisol are believed to contribute to up to 40% of infertility cases. Growth and reproduction are also influenced by thyroid hormone function which is adversely affected not only through CRH induced inhibition of TRH release but also by impaired peripheral conversion of the relatively inactive tetraiodothyronine into active triiodothyronine.
Thus, when cortisol levels are chronically and abnormally elevated, numerous other hormone systems are adversely affected which may result in symptomatology despite 'normal' lab results. Keep this is mind when initiating hormone replacement with hormones since the catabolic action of cortisol can overpower the anabolic effects of the other hormones, DHEA in particular. Checking anabolic/catabolic balance via urine is an available diagnostic tool.