Recent Secular Trends in Pubertal Timing: Implications for Evaluation and Diagnosis of Precocious Puberty

Abstract

The decline in age at puberty in the general population has been paralleled by an increase in the number of girls referred for evaluation of precocious puberty (PP). In 1999, The Lawson Wilkins Pediatric Endocrine Society recommended a lowering of the age limit for evaluation of PP in girls. However, the limited evidence on which these recommendations were based led many experts to question these new suggestions. The emergence of new European pubertal timing data evaluated by robust clinical as well as biochemical markers has broadened our insight on how to interpret the recent pubertal changes. The recent pubertal trends have resulted in a concomitant lowering of the lower limit of normality of the pubertal onset. However, evidence suggests that age at the gonadotropin and sex steroid surges have not changed. Thus, it looks as if an increasing proportion of contemporary early pubertal girls may experience isolated gonadotropin-independent thelarche rather than central PP, which may not be discernible on pubertal examination alone. Thus, the population-based limits of normality should not be directly translated into revision of age limits for evaluation of PP due to the risk of misdiagnosing rapid progressive PP as well as intracranial and other underlying pathology.

Puberty in a sample of Brazilian schoolgirls: timing and anthropometric characteristics

“…This difference is could be due to the contribution of ethnic differences because we have noticed that our sample is miscegenated with genetic characteristics that are definitely different from those of the British girls evaluated by those authors. Moreover, our study is much more recent, and it is recognised that there is a phenomenon of secular reduction in the age of onset of the secondary sexual characteristics in several populations, especially in developing countries such as Brazil (4,5).…”

“…However, it has been reported that the age and time of progression of puberty have diminished (3,4) worldwide, and studies have indicated a secular reduction in the age of menarche and thelarche (3)(4)(5). Based on these data, the Lawson Wilkins Paediatric Endocrine Society (LWPES) even suggested that it could be considered normal for pubertal evolution to begin at 7 years of age for white girls and 6 years of age for black girls (6).…”

Risky, early, controversial. Puberty in medical discourses

“…In the absence of reliable data from European sources, work on the subject has also shown disagreement over the appropriateness of transposing data from the US: some use the data to support their clinical observations (Pienkowski and Granjean, 2008;Cartault et al, 2008); others contest their validity given the differences between the populations under study and the results (even interim) obtained (Gaudineau et al, 2010;Sørensen et al, 2012). …”

Puberty: When is it normal?

“…These findings reinforce the idea that the prevalence of sexual precocity is underestimated. In fact, parent's education regarding the detection of first pubertal signs is essential for prompt recognition of precocious puberty (8,9).…”

“…(7), the prevalence of overweight and obesity was 18.8 and 12.5%, respectively. Other studies have documented that higher BMI is correlated with earlier onset of puberty, implicating leptin, a fat cell-derived protein, and other adipokines required for normal gonadotropin secretion (3,6,9). However, it is not clear if increased adiposity is the cause or the consequence of early pubertal development in girls.…”