Precocious Puberty (part 1 of 3)
Dr. Joel Steelman's series on precocious puberty (part 1)
Public awareness of precocious puberty (early puberty) has increased in recent years. News reports of earlier age of puberty in children provoke parental anxiety. When visiting with families dealing with these concerns, questions arise:
- Why did this happen to my child?
- What does this mean for my child?
- Will my daughter start her period in elementary school?
Precocious puberty remains a relatively rare condition in the general childhood population with the most recent prevalence statistics shown below.
- 20 per 10,000 girls
- 5 per 10,000 boys.
The vast majority of children affected by precocious puberty are girls. In spite of the concerning news, the most recent statistics still don’t show menarche (the age when girls start their period) has changed much in the last fifty years, remaining at an average of 12 ½ years old.
Although rare in the general childhood population, precocious puberty is a common problem in the realm of pediatric endocrinology. A recent surge in the number of new visits to me for precocious puberty concerns inspired me to write about this confusing, anxiety-provoking topic.
Understanding precocious puberty first requires an understanding of normal puberty. However, there is an ongoing debate in the medical community questioning what the normal start of puberty is. The historical guidelines used for defining the start of normal puberty dates back to research reported in the 1950s and 1960s in mainly white populations. Newer studies done in the 1990s, which were much larger in scope and included a racially diverse mix of children, have questioned prior assumptions.
A review of past as well as current proposed guidelines is shown below.
|Age of normal start of puberty||Historical Guidelines for age when normal puberty begins||Newer Proposed Guidelines for age when normal puberty begins|
|Boys||9 years old||9 years old|
|Girls||8 years old||7 years old for whites6 years old for blacks|
Understanding puberty also requires understanding the key hormones and systems involved in puberty. The two hormone systems of the body responsible for starting and sustaining puberty are the pituitary gland and the adrenal gland. Their location and primary roles are summarized in the illustration below.
Adrenarche is the term used to describe the activation of the adrenal gland. Recently, body fat and leptin, a hormone produced by body fat, were identified as strong factors in stimulating adrenarche. Androgens produced by the adrenal gland cause body hair, oily skin, acne, and body odor.
Estrogen or testosterone production is stimulated by hormones known as gonadotropins which are produced by the pituitary gland . How activation of the pituitary gland occurs to start puberty remains an area of ongoing research. We do know that neurological signals from the hypothalamus, a portion of the brain intimately linked to the pituitary, plays a role in activating puberty from the pituitary gland.
With an overview of normal puberty definitions, I’ll tackle the huge topic of what are causes of precocious puberty in the next article.
About the author
As a self-described ‘techie,’ Joel Steelman, M.D., has a keen interest in the wise use of technology to improve medical care. Since 2001, he has helped implement electronic medical recordkeeping in two endocrine practices.