Second, there is some evidence that premature adrenarche may indicate that there was an abnormality of intrauterine energy environment and growth. As mentioned above, premature adrenarche occurs more often in children with intrauterine growth retardation and in overweight children. Some of these same studies have demonstrated that some girls who display premature adrenarche may continue to have excessive androgen levels in adolescence. This can result in hirsutism or menstrual irregularities due to anovulation referred to as polycystic ovary syndrome .
[Continued from above] . . first line of defense and response to physical and emotional stresses. The adrenal glands are shaped like the French Emperor Napoleon's hat and, just as Napoleon's three-cornered hat sat on his head, so each gland is perched on each of the kidneys. These glands are about one to two inches in length; they weigh only a fraction of an ounce each yet are among the most productive of all of the body's glands, secreting more than three dozen hormones. The adrenal cortex takes instruction from the pituitary glands and have important effects on physical characteristics, development and growth. The adrenal gland has two parts. The cortex, or outer, yellow layer, takes its instructions from the pituitary hormone ACTH. The hormones secreted here are called steroids and have three main types: those which control the balance of sodium and potassium in the body; those which raise the level of sugar in the blood; and sex hormones. The inner, reddish brown layer of the adrenal gland (the adrenal medulla) makes two types of hormones; this part of the adrenal gland takes its instruction from the nervous system, producing chemicals which react to fear and anger and are sometimes called fight or flight hormones.
The secretion of cortisol is mainly controlled by three inter-communicating regions of the body, the hypothalamus in the brain, the pituitary gland and the adrenal gland . This is called the hypothalamic–pituitary–adrenal axis. When cortisol levels in the blood are low, a group of cells in a region of the brain called the hypothalamus releases corticotrophin-releasing hormone , which causes the pituitary gland to secrete another hormone, adrenocorticotropic hormone , into the bloodstream. High levels of adrenocorticotropic hormone are detected in the adrenal glands and stimulate the secretion of cortisol, causing blood levels of cortisol to rise. As the cortisol levels rise, they start to block the release of corticotrophin-releasing hormone from the hypothalamus and adrenocorticotropic hormone from the pituitary. As a result the adrenocorticotropic hormone levels start to drop, which then leads to a drop in cortisol levels. This is called a negative feedback loop.