Effets des perturbateurs endocriniens au cours du développement : interactions précoces et délais variables de manifestation

peer reviewe

Early homeostatic disturbances of human growth and maturation by endocrine disrupters

peer reviewedWe attempt to delineate and integrate aspects of growth and development that could be affected by endocrine disrupters [endocrine-disrupting compounds (EDC)], an increasing public health concern. RECENT FINDINGS: Epidemiological and experimental data substantiate that fetal and early postnatal life are critical periods of exposure to endocrine disrupters, with possible transgenerational effects. The EDC effects include several disorders of the reproductive system throughout life (abnormalities of sexual differentiation, infertility or subfertility and some neoplasia) and disorders of energy balance (obesity and metabolic syndrome). The mechanisms are consistent with the concept of 'developmental origin of adult disease'. They could involve cross-talk between the factors controlling reproduction and those controlling energy balance, both in the hypothalamus and peripherally. SUMMARY: Due to ubiquity of endocrine disrupters and lifelong stakes of early exposure, individual families should be provided by pediatricians with recommendations following the precautionary principle, that is prevention or attenuation of conditions possibly detrimental to health before the evidence of such adverse effects is complete and undisputable

Linear growth as a function of age at onset of puberty and sex steroid dosage: therapeutic implications

Puberty plays a dual role in growth: height velocity is markedly accelerated while the rate of skeletal maturation is also increased with resultant fusion of epiphyseal cartilages. Thus, puberty can be considered as a growth-promoting event as well as the final height-limiting process. This concept is illustrated by early exposure to sex steroids such as occurs in central precocious puberty or congenital adrenal hyperplasia. These conditions accelerate growth but result in short adult height (1–6). The basic question addressed in this paper is how hormonal changes at puberty and the age of their occurrence influence growth rate and adult height. This query has practical implications including timing and dosage of sex steroid replacement therapy in hypogonadal patients and the use of GnRH agonist therapy in patients with precocious puberty or short stature. These issues may have profound social import since numerous (mostly uncharted) psychological aspects of adolescence may be related to stature and the timing of sexual development

IHÉS, la preuve par 50

L’Institut des hautes études scientifiques (IHÉS) de Bures-sur-Yvette est un institut de recherche avancée en mathématiques et physique théorique avec, depuis 2000, une ouverture sur l’interface mathématiques-biologie et médecine. Conçu comme le pendant européen du célèbre Institute for Advanced Study (IAS) de Princeton, l’IHÉS a fêté ses 50 ans en 2008.The Institut des hautes études scientifiques (IHÉS) is an institute of advanced research in mathematics and theoretical physics that has developed, since 2000, new activities at the interface betweeen mathematics and biology and medicine. The IHÉS celebrated its 50th anniversary in 2008

Endocrine-disrupting chemicals and human growth and maturation: a focus on early critical windows of exposure.

Endocrine-disrupting chemicals (EDCs) are exogenous substances that interfere with hormone synthesis, metabolism, or action. In addition, some of them could cause epigenetic alterations of DNA that can be transmitted to the following generations. Because the developing organism is highly dependent on sex steroids and thyroid hormones for its maturation, the fetus and the child are very sensitive to any alteration of their hormonal environment. An additional concern about that early period of life comes from the shaping of the homeostatic mechanisms that takes place also at that time with involvement of epigenetic mechanisms along with the concept of fetal origin of health and disease. In this chapter, we will review the studies reporting effects of EDCs on human development. Using a translational approach, we will review animal studies that can shed light on some mechanisms of action of EDCs on the developing organism. We will focus on the major hormone-dependent stages of development: fetal growth, sexual differentiation, puberty, brain development, and energy balance. We will also discuss the possible epigenetic effects of EDCs on human development