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Self-reported onset of puberty and subsequent semen quality and reproductive hormones in healthy young men.
Is there an association between pubertal onset and subsequent reproductive health in young men?
Self-reported later onset of puberty was associated with reduced semen quality and altered serum levels of reproductive hormones among 1068 healthy, young Danish men.
The long-term effects of variations in the onset of male puberty on subsequent reproduction remain largely unstudied.
In a cross-sectional study, young healthy Danish men were approached when they attended a compulsory medical examination to determine their fitness for military service from 2008 to 2012.
A total of 1068 healthy, young Danish men (mean age 19 years) participated. They were asked to assess whether onset of penile and testicular growth, development of pubic hair and voice break occurred earlier, at the same time as or later than their peers. Their semen quality (semen volume, sperm concentration, total sperm count and percentages of motile and morphologically normal spermatozoa) and serum concentrations of sex hormones (LH, FSH, total testosterone, SHBG, inhibin B) and testicular size were determined.
The response rate was 29%. Of the 1068 men who then participated, 652 answered the questions about penile growth and pubic hair development and were therefore included in the analysis. Self-reported later onset of puberty was associated with a 25% reduction in sperm concentration (95% CI -41%; -4%), a 40% reduction in total sperm count (-55%; -21%), a 1.6% age point reduction in morphological normal spermatozoa (-2.9; -0.3) and a 1.6 ml reduction in testicular size (-2.4 and -0.8 ml), after adjustment for confounders. Self-reported later onset of puberty was also associated with a 9% (3%; 15%) reduction in free testosterone and a 16% (2%; 31%) increase in FSH, after adjustment for confounders.
Our study was cross-sectional and reverse causality cannot be ruled out. In addition, we cannot rule out the possibility that the men with late puberty onset had not yet fully matured although most were in Tanner stage 5.
Approximately 15% of young Danish men have self-reported later onset of puberty than their peers. We found poorer testicular function in young men with a history of later pubertal development, suggesting that timing of pubertal onset may be a fundamental marker of male reproductive health. However, we cannot exclude the possibility that these men had not fully matured at the time of examination and therefore their semen quality may yet improve, which makes follow-up important.
This work was supported by the Danish Council for Strategic Research, Program Commission on Health, Food and Welfare (project number 2101-08-0058), Rigshospitalet (grants 961506336 and R42-A1326), European Union, DEER (grant agreement no 212844), the Danish Ministry of Health and the Danish Environmental Protection Agency and Kirsten and Freddy Johansens Foundation (grant 95-103-72087). There are no competing interests.
Jensen TK
,Finne KF
,Skakkebæk NE
,Andersson AM
,Olesen IA
,Joensen UN
,Bang AK
,Nordkap L
,Priskorn L
,Krause M
,Jørgensen N
,Juul A
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Compensated reduction in Leydig cell function is associated with lower semen quality variables: a study of 8182 European young men.
Is the Leydig cell function of young European men associated with semen quality?
Compensated reduction in Leydig cell function, defined as increased LH concentration combined with adequate testosterone production is associated with lower semen quality.
Semen quality of young European men shows a heterogeneous pattern. Many have sperm counts below and in the lower WHO reference where there nevertheless is a significant risk of subfecundity. Little is known about differences in Leydig cell function between men with semen quality below and within the WHO reference range.
A coordinated, cross-sectional population-based study of 8182 men undertaken in 1996-2010.
Young men (median age 19.1 years) were investigated in centres in Denmark, Estonia, Finland, Germany Latvia, Lithuania, and Spain. The men originated from the general populations, all were young, almost all were unaware of their fecundity and each provided a semen and blood sample. Associations between semen parameters and serum levels of testosterone and luteinising hormone (LH), calculated free testosterone, and ratios between serum testosterone and LH were determined.
Serum testosterone levels were not associated with sperm concentrations, total sperm counts, or percentage of motile or morphologically normal spermatozoa. There was an inverse association between the semen parameters and serum LH levels, and accordingly a positive association to testosterone/LH ratio and calculated-free-testosterone/LH ratio.
The size of the study mitigates the intra-individual variability concern. The distinction between different sub-categories of sperm motility and sperm morphology is subjective despite training. However, inter-observer variation would tend towards non-differential misclassification and would decrease the likelihood of detecting associations between reproductive hormone levels and semen variables, suggesting that the presented associations might in reality be even stronger than shown. Although we adjusted for confounders, we cannot of course exclude that our results can be skewed by selection bias or residual confounding.
Compensated reduction in Leydig cell function, defined as increased LH concentration combined with adequate testosterone production is associated with lower semen quality. This is apparent even within the WHO reference range of semen quality. It is unknown whether impaired Leydig cell function in young men may confer an increased risk of acquired testosterone deficiency later in life.
Support from The Research Fund of Rigshospitalet (grant no. R42-A1326) to N.J. made this study possible. The background studies of young men have been supported economically by several grants. ITALIC! Denmark: The European Union (contract numbers BMH4-CT96-0314, QLK4-CT-1999-01422, QLK4-CT-2002-00603 and most recently FP7/2007-2013, DEER Grant agreement no. 212844), The Danish Research Council (grants nos. 9700833 2107-05-0006), The Danish Agency for Science, Technology and Innovation (Grant no. 271070678), Rigshospitalet (Grant no. 961506336), The University of Copenhagen (Grant no. 211-0357/07-3012), The Danish Ministry of Health and the Danish Environmental Protection Agency, A.P. Møller and wife Chastine McKinney Møllers foundation, and Svend Andersens Foundation. ITALIC! Finland: European Union (contract numbers BMH4-CT96-0314, QLK4-CT-1999-01422, QLK4-CT- 2002-00603 and most recently FP7/2008-2012, DEER Grant agreement no. 212844), The Academy of Finland, Turku University Hospital Funds, Sigrid Juselius Foundation. ITALIC! Estonia, Latvia and Lithuania: European Union (QLRT-2001-02911), the Estonian Science Foundation, grant number 2991, Lithuanian Foundation for Research, Organon Agencies B.V. and the Danish Research Council, grant no. 9700833. ITALIC! Germany: European Union (contract numbers QLK4-CT-2002-00603). ITALIC! Spain: European Commission QLK4-1999-01422. M.F. received support from the Spanish Ministry of Science and Innovation (Program Ramon y Cajal). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. None of the authors have any competing interests to declare.
Jørgensen N
,Joensen UN
,Toppari J
,Punab M
,Erenpreiss J
,Zilaitiene B
,Paasch U
,Salzbrunn A
,Fernandez MF
,Virtanen HE
,Matulevicius V
,Olea N
,Jensen TK
,Petersen JH
,Skakkebæk NE
,Andersson AM
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PFOS (perfluorooctanesulfonate) in serum is negatively associated with testosterone levels, but not with semen quality, in healthy men.
Joensen UN
,Veyrand B
,Antignac JP
,Blomberg Jensen M
,Petersen JH
,Marchand P
,Skakkebæk NE
,Andersson AM
,Le Bizec B
,Jørgensen N
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Reproductive hormones of ICSI-conceived young adult men: the first results.
Are reproductive hormone levels (FSH, LH, inhibin B and testosterone) in male offspring conceived by ICSI because of male infertility comparable with those from peers born after spontaneous conception?
In this cohort of 54 young men conceived by ICSI because of male-factor infertility, mean and median reproductive hormone levels were found to be comparable with results from spontaneously conceived peers, but ICSI-conceived men were more likely to have low inhibin B (<10th percentile) and high FSH (>90th percentile) levels.
Since the worldwide oldest ICSI offspring have recently reached young adulthood, their reproductive health can now be investigated. This typically involves semen analysis and a hormonal profiling including the measurement of FSH, LH, inhibin B and testosterone. Circulating levels of FSH and inhibin B are generally known as markers of the exocrine function of the testis, i.e. spermatogenesis, while LH and testosterone reflect its endocrine function. We have previously observed a normal pubertal development and comparable levels of inhibin B and testosterone among pubertal ICSI boys when compared to spontaneously conceived peers. However, at present, information on the gonadal function of ICSI offspring in adulthood is still lacking.
This study, conducted between March 2013 and April 2016 at the UZ Brussel, is part of a larger follow-up project focusing on reproductive and metabolic health of young adults between 18 and 22 years and conceived after ICSI because of male infertility. The ICSI men are part of a longitudinally followed cohort while the spontaneously conceived controls were recruited cross-sectionally.
Results of a single fasting blood sample from 54 young adult ICSI men were compared to that of 57 spontaneously conceived peers. Reproductive hormone analysis involved FSH, LH, testosterone and inhibin B measurement. Furthermore, the association between their reproductive hormones and their sperm parameters was examined. Data were analyzed by multiple linear and logistic regression adjusted for covariates.
ICSI men had comparable mean levels of FSH, LH, testosterone and inhibin B in comparison to spontaneously conceived counterparts, even after adjustment for confounders, such as age, BMI and season. Young ICSI-conceived men were more likely to have inhibin B levels below the 10th percentile (<125.2 ng/l; Adjusted Odds Ratio (AOR) 4.0; 95% CI: 0.9-18.4; P = 0.07) compared with spontaneously conceived peers and were more likely to have FSH levels above the 90th percentile (>5.5 IU/L; AOR 3.3; 95% CI: 0.9-11.9; P = 0.06) compared with spontaneously conceived peers, but neither difference reached statistical significance. FSH, LH and inhibin B, but not testosterone, levels were significantly associated with sperm concentration and total sperm count.
The main limitation is the small study population. Furthermore, the results of this study should be interpreted according to the background of the participants: all subjects in our study group were conceived by ICSI because of severe male infertility and hence the results cannot be generalized to all ICSI offspring because the indications for performing ICSI have since been widened.
These first results in a small group of ICSI men show reassuring reproductive hormonal levels. However, larger studies are required to confirm our results. Since inhibin B and FSH are consistently correlated with semen characteristics, we would suggest that the reproductive status of young adults conceived by ICSI is explored with a hormonal assessment given its easier acceptance compared to semen sampling.
This study was supported by Methusalem grants and by grants from Wetenschappelijk Fonds Willy Gepts, all issued by the Vrije Universiteit Brussel (VUB). A grant from the Belgian Society for Pediatric Endocrinology and Diabetology was received for this project. All co-authors, except M.B. and H.T., declare no conflict of interest. M.B. has received consultancy fees from MSD, Serono Symposia and Merck. The Universitair Ziekenhuis Brussel (UZ Brussel) and the Centre for Medical Genetics have received several educational grants from IBSA, Ferring, Organon, Shering-Plough, Merck for establishing the database for follow-up research and organizing the data collection. The institution of HT receives research grants from the 'Research Fund of Flanders' (FWO), an unconditional grant from Ferring for research on testicular stem cells and research grants from Ferring, Merck, MSD, Roche, Besins, Goodlife and Cook for several research projects in female infertility. H.T. has received consultancy fees from Finox, Abbott and ObsEva for research projects in female infertility.
N/A.
Belva F
,Roelants M
,De Schepper J
,Van Steirteghem A
,Tournaye H
,Bonduelle M
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Testicular function in a birth cohort of young men.
By investigating a birth cohort with a high ongoing participation rate to derive an unbiased population, what are the parameters and influences upon testicular function for a population not selected with regard to fertility?
While varicocele, cryptorchidism and obesity may impact on human testicular function, most common drug exposures and the presence of epididymal cysts appear to have no or minimal adverse impact.
The majority of previous attempts to develop valid reference populations for spermatogenesis have relied on potentially biased sources such as recruits from infertility clinics, self-selected volunteer sperm donors for research or artificial insemination or once-fertile men seeking vasectomy. It is well known that studies requiring semen analysis have low recruitment rates which consequently question their validity. However, there has been some concern that a surprisingly high proportion of young men may have semen variables that do not meet all the WHO reference range criteria for fertile men, with some studies reporting that up to one half of participants have not meet the reference range for fertile men. Reported median sperm concentrations have ranged from 40 to 60 million sperm/ml.
The Western Australian Pregnancy Cohort (Raine) was established in 1989. At 20-22 years of age, members of the cohort were contacted to attend for a general follow-up, with 753 participating out of the 913 contactable men. Of these, 423 men (56% of participants in the 20-22 years cohort study, 46% of contactable men) participated in a testicular function study. Of the 423 men, 404 had a testicular ultrasound, 365 provided at least one semen sample, 287 provided a second semen sample and 384 provided a blood sample.
Testicular ultrasound examinations were performed at King Edward Memorial Hospital, Subiaco, Perth, for testicular volume and presence of epididymal cysts and varicoceles. Semen samples were provided and analysed by standard semen assessment and a sperm chromatin structural assay (SCSA) at Fertility Specialists of Western Australia, Claremont, Perth. Serum blood samples were provided at the University of Western Australia, Crawley, Perth and were analysed for serum luteinizing hormone (LH), follicular stimulating hormone (FSH), inhibin B, testosterone, dihydrotestosterone (DHT), dehydroepiandrosterone (DHEA), estradiol, estrone and the primary metabolites of DHT: 5α-androstane-3α,17β-diol (3α-diol) and 5-α androstane-3-β-17-beta-diol (3β-diol). Serum steroids were measured by liquid chromatography, mass spectrometry and LH, FSH and inhibin B were measured by ELISA assays.
Cryptorchidism was associated with a significant reduction in testicular (P = 0.047) and semen (P = 0.027) volume, sperm concentration (P = 0.007) and sperm output (P = 0.003). Varicocele was associated with smaller testis volume (P < 0.001), lower sperm concentration (P = 0.012) and total sperm output (P = 0.030) and lower serum inhibin B levels (P = 0.046). Smoking, alcohol intake, herniorrhaphy, an epididymal cyst, medication and illicit drugs were not associated with any significant semen variables, testicular volume or circulating reproductive hormones. BMI had a significantly negative correlation with semen volume (r = -0.12, P = 0.048), sperm output (r = -0.13, P = 0.02), serum LH (r = -0.16, P = 0.002), inhibin B (r = -0.16, P < 0.001), testosterone (r = -0.23, P < 0.001) and DHT (r = -0.22, P < 0.001) and a positive correlation with 3αD (r = 0.13, P = 0.041) and DHEA (r = 0.11, P = 0.03). Second semen samples compared with the first semen samples in the 287 participants who provided two samples, with no significant bias by Bland-Altman analysis. Testis volume was significantly correlated positively with sperm concentration (r = 0.25, P < 0.001) and sperm output (r = 0.29, P < 0.001) and inhibin B (r = 0.42, P < 0.001), and negatively correlated with serum LH (r = -0.24, P < 0.001) and FSH (r = -0.32, P < 0.001). SCSA was inversely correlated with sperm motility (r = -0.20, P < 0.001) and morphology (r = -0.16, P = 0.005). WHO semen reference criteria were all met by only 52 men (14.4%). Some criteria were not met at first analysis in 15-20% of men, including semen volume (<1.5 ml, 14.8%), total sperm output (<39 million, 18.9%), sperm concentration (<15 million/ml, 17.5%), progressive motility (<32%, 14.4%) and morphologically normal sperm (<4%, 26.4%), while all five WHO criteria were not met in four participants (1.1%).
This was a large cohort study; however, potential for recruitment bias still exists. Men who did not participate in the testicular evaluation study (n = 282) did not differ from those who did (n = 423) with regard to age, weight, BMI, smoking or circulating reproductive hormones (LH, FSH, inhibin B, T, DHT, E2, E1, DHEA, 3α-diol, 3β-diol), but were significantly shorter (178 versus 180 cm, P = 0.008) and had lower alcohol consumption (P = 0.019) than those who did participate.
This study demonstrated the feasibility of establishing a birth cohort to provide a relatively unbiased insight into population-representative sperm output and function and of investigating its determinants from common exposures. While varicocele, cryptorchidism and obesity may impact on human testicular function, most common drug exposures and the presence of epididymal cysts appear to have little adverse impact, and this study suggests that discrepancies from the WHO reference ranges are expected, due to its derivation from non-population-representative fertile populations.
Hart RJ
,Doherty DA
,McLachlan RI
,Walls ML
,Keelan JA
,Dickinson JE
,Skakkebaek NE
,Norman RJ
,Handelsman DJ
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