TY - JOUR
T1 - Male Reproductive Disorders and Fertility Trends
T2 - Influences of Environment and Genetic Susceptibility
AU - Skakkebaek, Niels E
AU - Rajpert-De Meyts, Ewa
AU - Buck Louis, Germaine M
AU - Toppari, Jorma
AU - Andersson, Anna-Maria
AU - Eisenberg, Michael L
AU - Jensen, Tina Kold
AU - Jørgensen, Niels
AU - Swan, Shanna H
AU - Sapra, Katherine J
AU - Ziebe, Søren
AU - Priskorn, Lærke
AU - Juul, Anders
N1 - Copyright © 2016 the American Physiological Society.
PY - 2015/11/18
Y1 - 2015/11/18
N2 - It is predicted that Japan and European Union will soon experience appreciable decreases in their populations due to persistently low total fertility rates (TFR) below replacement level (2.1 child per woman). In the United States, where TFR has also declined, there are ethnic differences. Caucasians have rates below replacement, while TFRs among African-Americans and Hispanics are higher. We review possible links between TFR and trends in a range of male reproductive problems, including testicular cancer, disorders of sex development, cryptorchidism, hypospadias, low testosterone levels, poor semen quality, childlessness, changed sex ratio, and increasing demand for assisted reproductive techniques. We present evidence that several adult male reproductive problems arise in utero and are signs of testicular dysgenesis syndrome (TDS). Although TDS might result from genetic mutations, recent evidence suggests that it most often is related to environmental exposures of the fetal testis. However, environmental factors can also affect the adult endocrine system. Based on our review of genetic and environmental factors, we conclude that environmental exposures arising from modern lifestyle, rather than genetics, are the most important factors in the observed trends. These environmental factors might act either directly or via epigenetic mechanisms. In the latter case, the effects of exposures might have an impact for several generations post-exposure. In conclusion, there is an urgent need to prioritize research in reproductive physiology and pathophysiology, particularly in highly industrialized countries facing decreasing populations. We highlight a number of topics that need attention by researchers in human physiology, pathophysiology, environmental health sciences, and demography.
AB - It is predicted that Japan and European Union will soon experience appreciable decreases in their populations due to persistently low total fertility rates (TFR) below replacement level (2.1 child per woman). In the United States, where TFR has also declined, there are ethnic differences. Caucasians have rates below replacement, while TFRs among African-Americans and Hispanics are higher. We review possible links between TFR and trends in a range of male reproductive problems, including testicular cancer, disorders of sex development, cryptorchidism, hypospadias, low testosterone levels, poor semen quality, childlessness, changed sex ratio, and increasing demand for assisted reproductive techniques. We present evidence that several adult male reproductive problems arise in utero and are signs of testicular dysgenesis syndrome (TDS). Although TDS might result from genetic mutations, recent evidence suggests that it most often is related to environmental exposures of the fetal testis. However, environmental factors can also affect the adult endocrine system. Based on our review of genetic and environmental factors, we conclude that environmental exposures arising from modern lifestyle, rather than genetics, are the most important factors in the observed trends. These environmental factors might act either directly or via epigenetic mechanisms. In the latter case, the effects of exposures might have an impact for several generations post-exposure. In conclusion, there is an urgent need to prioritize research in reproductive physiology and pathophysiology, particularly in highly industrialized countries facing decreasing populations. We highlight a number of topics that need attention by researchers in human physiology, pathophysiology, environmental health sciences, and demography.
KW - Environmental Exposure
KW - Fertility
KW - Gene-Environment Interaction
KW - Genetic Predisposition to Disease
KW - Humans
KW - Incidence
KW - Infertility, Male
KW - Life Style
KW - Male
KW - Phenotype
KW - Population Dynamics
KW - Risk Factors
KW - Journal Article
KW - Research Support, Non-U.S. Gov't
KW - Review
U2 - 10.1152/physrev.00017.2015
DO - 10.1152/physrev.00017.2015
M3 - Review
C2 - 26582516
SN - 0031-9333
VL - 96
SP - 55
EP - 97
JO - Physiological Reviews
JF - Physiological Reviews
IS - 1
ER -
