Puberty, Precocious

Various studies show an increase in the number of cases of early puberty in girls with breast development with a variable clinical presentation and evolution. This increasing phenomenon concerns girls between 6 and 8 years old. In a large number of cases, from 70 to 95% depending on the series, no medical cause is found and environmental factors are suspected to be involved. Descriptive studies of these patients are scarce and not always provide an overview of all the parameters in line with the concept of the exposome. The PENELOPE clinical trial will allow to analyze a large number of parameters, including the adipose tissue, its metabolism, the endocrine disruptors, and the epigenetic modifications, and to study the impact of environmental health measures in the evolution of these parameters. The data from the analyses of the endocrine disruptors of the patients will be explored in parallel in experimental models (amphibians, murine, cellular) in order to test potential mechanistic hypotheses.

The age of puberty has fluctuated throughout history. Recent data shows an increase in the age of onset of puberty signs, in the United States but also in Europe. A recent Public Health France study published in 2018 reports an increase in the incidence of precocious puberty with geographical heterogeneity. The consequences of these appearances include the early onset of menarche, short adult height and the psychological impact. Due to a lack of studies and additional data, the reasons for this development are difficult to understand. Among current hypotheses, the entanglement with the evolution of our environment is at the forefront: the action of environmental endocrine disruptors and nutritional factors could play a role in the process of early appearance of pubertal signs. The establishment of a national observatory for early and advanced puberty in collaboration with pediatric endocrinologists (on the front line) would allow a reliable and precise field approach, capable of supplementing epidemiological data, which are currently insufficient. The investigators hypothesize that the establishment of an observatory of pubertal advances (early puberty and advanced puberty) in private medicine is possible, with inclusion of at least 75% of eligible patients, and collection of at least 80% of data.

The COPENHAGEN School Study is a combined cross-sectional and longitudinal study of healthy Danish school children. This study will by clinical examinations and withdrawal of blood samples investigate whether age of pubertal onset is continuing to decline in Denmark over the past 15 years. Furthermore, we will investigate the mechanism driving earlier onset of puberty and the long term health risks of extremely early puberty using Danish registry data

There is an urgent need to obtain more knowledge about the influence of weight and metabolism on the timing and progression of puberty. The age of pubertal onset has been constantly declining during the last decades and extremely early maturation may have yet unseen consequences for the psychosocial development of the child as well as detrimental long-term health consequences. Studies have shown that girls with early-onset puberty are more likely than their peers to enter sexual relationships at a younger age, to experience more psychological distress, and to engage in risk-taking behaviors. In addition, early maturation may have long-term health consequences since earlier menarche is associated with an increased risk of all-cause mortality and cardiovascular disease later in life in large epidemiological studies. The exact aetiology for the earlier onset of puberty in the general population remains to be elucidated, and the cause is probably to be found in a complex interplay between genetic, epigenetic, environmental and metabolic factors. However, world-wide there is a concerning increasing prevalence of overweight in childhood and early puberty is one of many consequences of this. Environmental factors such as endocrine disrupting chemicals have been suggested to play a role for both obesity and precocious puberty either directly or through epigenetic moderation. The current study of a Danish National cohort will explore the incidence and aetiology of precocious puberty for better treatment and prevention. Furthermore, a placebo-controlled randomized controlled trial may give a novel mechanistic insight of the interplay between insulin sensitivity and sex steroids. To our knowledge this study is the first of its kind and may lead to novel alternative treatment strategy for overweight girls with early puberty that may have beneficial effects on long-term morbidity and mortality.