TY - JOUR

T1 - Timing of puberty in relation to semen characteristics, testicular volume, and reproductive hormones

T2 - a cohort study

AU - Brix, Nis

AU - Gaml-Sørensen, Anne

AU - Ernst, Andreas

AU - Arendt, Linn Håkonsen

AU - Lunddorf, Lea Lykke Harrits

AU - Toft, Gunnar

AU - Tøttenborg, Sandra S.

AU - Hærvig, Katia Keglberg

AU - Høyer, Birgit Bjerre

AU - Hougaard, Karin S.

AU - Bonde, Jens Peter E.

AU - Ramlau-Hansen, Cecilia Høst

N1 - Publisher Copyright: © 2023 The Authors

PY - 2023

Y1 - 2023

N2 - Objective: To investigate whether the timing of puberty is associated with semen characteristics, testicular volume, and reproductive hormone levels. Design: Cohort study. Setting: Not applicable. Patients: The Danish National Birth Cohort and its subcohort, the Fetal Programming of Semen Quality cohort of 1,058 young men. Intervention(s): Self-reported information on the timing (younger, same age, older than peers) of the pubertal markers: voice break (primary exposure), pubic hair growth, regular shaving, and axillary hair growth. Main Outcome Measures(s): We estimated the relative differences with 95% confidence intervals for semen characteristics (semen volume, sperm concentration, total sperm count, sperm motility, percentage of morphologically normal spermatozoa), testicular volume, and reproductive hormones (follicle stimulating hormone [FSH], luteinizing hormone, sex hormone-binding globulin [SHBG], testosterone, estradiol, and free androgen index [FAI]) obtained at a median age of 19.2 years according to timing of pubertal development. Result(s): Compared with men reporting voice break “same age as peers,” men reporting voice break “older than peers” tended to have lower total sperm count (-12% [-25%, 4%]) and lower percent morphologically normal spermatozoa (-10% [-20%, 2%]), whereas men reporting voice break “younger than peers” tended to have a lower proportion of nonprogressive and immotile spermatozoa (-6% [-13%, 1%]) and larger testicular volume (7% [1%, 13%]). The pattern was less consistent for the other pubertal markers. For reproductive hormones, voice break “older than peers” tended to have higher FSH levels (24% [-1%, 55%]), higher SHBG levels (7% [0, 15%]), lower estradiol levels (-14% [-23%, -5%]), and lower FAI (-8% [-14%, -1%]), whereas voice break “younger than peers” tended to have higher luteinizing hormone levels (4% [-2%, 11%]), higher testosterone levels (5% [0%, 11%]), higher estradiol levels (17% [6%, 29%]), and higher FAI (4% [-2%, 11%]). When the categorical pubertal markers were analyzed as a linear term to assess dose dependence, older age at pubertal development was associated with higher FSH levels, higher SHBG levels, lower testosterone levels, lower estradiol levels, and lower FAI for most pubertal markers. Conclusion(s): These results lend weak support to the hypothesis that older age at pubertal development is associated with markers of reduced male fecundity, especially reproductive hormone levels, although associations with semen characteristics and testicular volume were statistically insignificant.

AB - Objective: To investigate whether the timing of puberty is associated with semen characteristics, testicular volume, and reproductive hormone levels. Design: Cohort study. Setting: Not applicable. Patients: The Danish National Birth Cohort and its subcohort, the Fetal Programming of Semen Quality cohort of 1,058 young men. Intervention(s): Self-reported information on the timing (younger, same age, older than peers) of the pubertal markers: voice break (primary exposure), pubic hair growth, regular shaving, and axillary hair growth. Main Outcome Measures(s): We estimated the relative differences with 95% confidence intervals for semen characteristics (semen volume, sperm concentration, total sperm count, sperm motility, percentage of morphologically normal spermatozoa), testicular volume, and reproductive hormones (follicle stimulating hormone [FSH], luteinizing hormone, sex hormone-binding globulin [SHBG], testosterone, estradiol, and free androgen index [FAI]) obtained at a median age of 19.2 years according to timing of pubertal development. Result(s): Compared with men reporting voice break “same age as peers,” men reporting voice break “older than peers” tended to have lower total sperm count (-12% [-25%, 4%]) and lower percent morphologically normal spermatozoa (-10% [-20%, 2%]), whereas men reporting voice break “younger than peers” tended to have a lower proportion of nonprogressive and immotile spermatozoa (-6% [-13%, 1%]) and larger testicular volume (7% [1%, 13%]). The pattern was less consistent for the other pubertal markers. For reproductive hormones, voice break “older than peers” tended to have higher FSH levels (24% [-1%, 55%]), higher SHBG levels (7% [0, 15%]), lower estradiol levels (-14% [-23%, -5%]), and lower FAI (-8% [-14%, -1%]), whereas voice break “younger than peers” tended to have higher luteinizing hormone levels (4% [-2%, 11%]), higher testosterone levels (5% [0%, 11%]), higher estradiol levels (17% [6%, 29%]), and higher FAI (4% [-2%, 11%]). When the categorical pubertal markers were analyzed as a linear term to assess dose dependence, older age at pubertal development was associated with higher FSH levels, higher SHBG levels, lower testosterone levels, lower estradiol levels, and lower FAI for most pubertal markers. Conclusion(s): These results lend weak support to the hypothesis that older age at pubertal development is associated with markers of reduced male fecundity, especially reproductive hormone levels, although associations with semen characteristics and testicular volume were statistically insignificant.

KW - cohort study

KW - Puberty

KW - reproductive hormones

KW - semen quality

KW - testicular volume

U2 - 10.1016/j.fertnstert.2023.05.164

DO - 10.1016/j.fertnstert.2023.05.164

M3 - Journal article

C2 - 37257718

AN - SCOPUS:85162869174

VL - 120

SP - 823

EP - 833

JO - Sexuality, Reproduction and Menopause

JF - Sexuality, Reproduction and Menopause

SN - 1546-2501

IS - 4

ER -