TY - JOUR
T1 - Postnatal Changes in Testicular Position Are Associated With IGF-I and Function of Sertoli and Leydig Cells
AU - Koskenniemi, Jaakko J
AU - Virtanen, Helena E
AU - Wohlfahrt-Veje, Christine
AU - Löyttyniemi, Eliisa
AU - Skakkebaek, Niels E
AU - Juul, Anders
AU - Andersson, Anna-Maria
AU - Main, Katharina M
AU - Toppari, Jorma
PY - 2018/4/1
Y1 - 2018/4/1
N2 - Context: Despite clinical guidelines calling for repetitive examination of testicular position during childhood, little is known of normal changes in testicular position during childhood, let alone factors that control it.Objective: To assess changes in and factors associated with testicular position during childhood.Design: Testicular position (the distance from the pubic bone to the upper pole of the testes) at birth, 3 months, 18 months, 36 months, and 7 years and reproductive hormones at 3 months were measured.Setting: Prenatally recruited, prospective longitudinal birth cohort.Participants: A total of 2545 boys were recruited prenatally in a Danish-Finnish birth cohort and had a testicular position examination available. A subset of 680 Danish and 362 Finnish boys had serum reproductive hormone concentrations and insulin-like growth factor I (IGF-I) determined at 3 months.Main Outcome Measures: Testicular distance to pubic bone (TDP), serum reproductive hormone, and IGF-I concentrations.Results: TDP increased from birth to 3 months and decreased thereafter. Length, gestational age, weight for gestational age, and penile length were positively associated with larger TDP and thus lower testicular position in a linear mixed-effect model. Furthermore, IGF-I concentration, inhibin B/follicle-stimulating hormone ratio, and testosterone/luteinizing hormone ratio were all independently and positively associated with longer TDP.Conclusions: We provide longitudinal data on postnatal changes in TDP. TDP is dynamic and associated with Leydig and Sertoli cell function as well as with IGF-I levels during the first months of life at mini-puberty of infancy. TDP may thus be a useful biomarker of postnatal testicular function.
AB - Context: Despite clinical guidelines calling for repetitive examination of testicular position during childhood, little is known of normal changes in testicular position during childhood, let alone factors that control it.Objective: To assess changes in and factors associated with testicular position during childhood.Design: Testicular position (the distance from the pubic bone to the upper pole of the testes) at birth, 3 months, 18 months, 36 months, and 7 years and reproductive hormones at 3 months were measured.Setting: Prenatally recruited, prospective longitudinal birth cohort.Participants: A total of 2545 boys were recruited prenatally in a Danish-Finnish birth cohort and had a testicular position examination available. A subset of 680 Danish and 362 Finnish boys had serum reproductive hormone concentrations and insulin-like growth factor I (IGF-I) determined at 3 months.Main Outcome Measures: Testicular distance to pubic bone (TDP), serum reproductive hormone, and IGF-I concentrations.Results: TDP increased from birth to 3 months and decreased thereafter. Length, gestational age, weight for gestational age, and penile length were positively associated with larger TDP and thus lower testicular position in a linear mixed-effect model. Furthermore, IGF-I concentration, inhibin B/follicle-stimulating hormone ratio, and testosterone/luteinizing hormone ratio were all independently and positively associated with longer TDP.Conclusions: We provide longitudinal data on postnatal changes in TDP. TDP is dynamic and associated with Leydig and Sertoli cell function as well as with IGF-I levels during the first months of life at mini-puberty of infancy. TDP may thus be a useful biomarker of postnatal testicular function.
KW - Anthropometry
KW - Child
KW - Child, Preschool
KW - Denmark
KW - Finland
KW - Follicle Stimulating Hormone/blood
KW - Humans
KW - Infant
KW - Infant, Newborn
KW - Inhibins/blood
KW - Insulin-Like Growth Factor I/metabolism
KW - Longitudinal Studies
KW - Luteinizing Hormone/blood
KW - Male
KW - Penis/anatomy & histology
KW - Pubic Bone/anatomy & histology
KW - Testis/anatomy & histology
KW - Testosterone/blood
U2 - 10.1210/jc.2017-01889
DO - 10.1210/jc.2017-01889
M3 - Journal article
C2 - 29408984
SN - 0021-972X
VL - 103
SP - 1429
EP - 1437
JO - Journal of Clinical Endocrinology and Metabolism
JF - Journal of Clinical Endocrinology and Metabolism
IS - 4
ER -