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Reproductive function in young Swedish men - Time trend, prenatal and adult exposure to smoking and phthalates

Axelsson, Jonatan LU (2015) In Lund University, Faculty of Medicine Doctoral Dissertation Series 2015:45.
Abstract (Swedish)
Popular Abstract in Swedish

Det har diskuterats huruvida mäns spermiekoncentration minskat och missbildningar i pojkars könsorgan ökat under den senare delen av 1900-talet. Med säkerhet har dock testikelcancer ökat flerfaldigt under samma tidsperiod.

Målet med denna avhandling var dels att undersöka huruvida skånska mäns spermakvalitet hade förändrats under det förra årtiondet, dels att studera samband mellan olika miljöfaktorer och manlig reproduktionsfunktion. Dessa miljöfaktorer var exponering för egen rökning, föräldrarnas rökning under graviditeten, samt för ftalater (en sorts plastmjukgörare) både under fostertiden och i vuxenlivet.

Vi rekryterade 314 unga män mellan år 2008 och 2010, främst från... (More)
Popular Abstract in Swedish

Det har diskuterats huruvida mäns spermiekoncentration minskat och missbildningar i pojkars könsorgan ökat under den senare delen av 1900-talet. Med säkerhet har dock testikelcancer ökat flerfaldigt under samma tidsperiod.

Målet med denna avhandling var dels att undersöka huruvida skånska mäns spermakvalitet hade förändrats under det förra årtiondet, dels att studera samband mellan olika miljöfaktorer och manlig reproduktionsfunktion. Dessa miljöfaktorer var exponering för egen rökning, föräldrarnas rökning under graviditeten, samt för ftalater (en sorts plastmjukgörare) både under fostertiden och i vuxenlivet.

Vi rekryterade 314 unga män mellan år 2008 och 2010, främst från Pliktverket i Kristianstad i samband med mönstringen, och i viss utsträckning också män från gymnasieskolor i Malmö-Lund-området. Männen fick besvara frågor om föräldrarnas rökning under graviditeten. Uppgifter om moderns rökning inhämtades även från Socialstyrelsens födelseregister.

Vi hade tillgång till blodprov från 112 av männens mödrar, tagna under graviditeten. Dessa prov hade tagits vid en screening för röda hund, varefter proven sparats i en biobank. I dessa prov, liksom i urin- och blodprov från männen själva, mättes nedbrytningsprodukter (metaboliter) av ftalater som markörer för exponering.

De rekryterade männens spermakvalitet jämfördes med den hos män rekryterade på ett liknande sätt år 2000 till 2001. Därefter studerades samband mellan exponering för både rökning och ftalater såväl under fostertiden som i vuxenlivet, och männens reproduktionsfunktion.

Vi fann inte någon förändring i spermakvaliteten under det senaste årtiondet.

Däremot hade de män vars fäder eller mödrar rökt under graviditeten ett påtagligt lägre spermieantal. Vidare tycktes exponering under fostertiden för de två ftalaterna di-isononylftalat (DiNP) och dietylhexylftalat (DEHP) ha samband med en sänkt testikelvolym respektive spermavolym. Slutligen hade exponering för DEHP och dibutylftalat (DBP) i vuxenlivet samband med en lägre andel framåtrörliga spermier, vilket kan tänkas påverka fertiliteten.

Således verkade både exponering föräldrarnas rökning under graviditeten och för ftalater under fostertiden samt i vuxenlivet, ha samband med en sänkt manlig reproduktionsfunktion. (Less)
Abstract
A decrease in male reproductive function, including sperm counts, during the second half of the 20th century, has been postulated. During this period, testicular cancer has increased several-fold. Environmental and lifestyle-related factors have been proposed as explanations for a possible negative trend in male reproductive function. One important lifestyle factor is smoking. However, smoking during pregnancy appears to play a greater role for a man's reproductive function than smoking by the man himself. As regards environmental chemicals, one type of compound to which humans are exposed is phthalates. These are often used as plasticizers in different consumer products. Several phthalates have been reported as decreasing male... (More)
A decrease in male reproductive function, including sperm counts, during the second half of the 20th century, has been postulated. During this period, testicular cancer has increased several-fold. Environmental and lifestyle-related factors have been proposed as explanations for a possible negative trend in male reproductive function. One important lifestyle factor is smoking. However, smoking during pregnancy appears to play a greater role for a man's reproductive function than smoking by the man himself. As regards environmental chemicals, one type of compound to which humans are exposed is phthalates. These are often used as plasticizers in different consumer products. Several phthalates have been reported as decreasing male reproductive function in laboratory animals, especially when given during the foetal period.

Between 2008 and 2010, 314 men from the general Swedish population were recruited. Their semen quality was compared with a group of men recruited in a similar manner between 2000 and 2001.

The participants also delivered serum and urinary samples and answered questionnaires concerning maternal and paternal smoking during pregnancy. Data on maternal smoking was additionally assessed through the Swedish Medical Birth Register. Through a Swedish screening program for rubella, maternal serum samples were retrieved from the men's prenatal period. We analysed metabolites of phthalates as exposure markers both in the maternal sera and in urine and serum of the men. Associations between parental smoking during pregnancy as well as phthalate metabolite levels, and parameters of male reproductive function were studied.

In summary, we found no change in semen quality between 2000-2001 and 2008-2010. However, both maternal and paternal smoking during pregnancy were associated with reduced sperm counts in men whose other parent did not smoke. In addition, prenatal exposure to diethylhexyl phthalate (DEHP) and diisononyl phthalate (DiNP) appeared to be associated with decreased semen volume, and exposure to DiNP as well with smaller testicular size. Finally, adult exposure to DEHP and dibutyl phthalate (DBP) were associated with decreased progressive sperm motility, and DEHP exposure was also linked to a higher proportion of immature sperm.

Thus, although no change in semen quality appeared to have occurred in Swedish men during the last decade, parental smoking and prenatal and adult exposure to certain phthalates may play a role in the male reproductive function. (Less)
Please use this url to cite or link to this publication:
author
supervisor
opponent
  • Professor Sharpe, Richard, Medical Research Council, University of Edinburgh, Storbrittanien
organization
publishing date
type
Thesis
publication status
published
subject
keywords
Semen analysis, maternal exposure, paternal exposure, smoking, phthalate
in
Lund University, Faculty of Medicine Doctoral Dissertation Series
volume
2015:45
pages
75 pages
publisher
Molecular Reproductive Medicine
defense location
Kvinnoklinikens aula, Plan 3, Jan Waldenströms gata 47, Skånes universitetssjukhus, Malmö
defense date
2015-05-22 13:00
ISSN
1652-8220
ISBN
978-91-7619-124-8
language
English
LU publication?
yes
id
8d0ce4e8-c937-41cd-932e-e0432d3afedb (old id 5337327)
date added to LUP
2015-04-29 15:36:53
date last changed
2016-09-19 08:44:45
@phdthesis{8d0ce4e8-c937-41cd-932e-e0432d3afedb,
  abstract     = {A decrease in male reproductive function, including sperm counts, during the second half of the 20th century, has been postulated. During this period, testicular cancer has increased several-fold. Environmental and lifestyle-related factors have been proposed as explanations for a possible negative trend in male reproductive function. One important lifestyle factor is smoking. However, smoking during pregnancy appears to play a greater role for a man's reproductive function than smoking by the man himself. As regards environmental chemicals, one type of compound to which humans are exposed is phthalates. These are often used as plasticizers in different consumer products. Several phthalates have been reported as decreasing male reproductive function in laboratory animals, especially when given during the foetal period.<br/><br>
Between 2008 and 2010, 314 men from the general Swedish population were recruited. Their semen quality was compared with a group of men recruited in a similar manner between 2000 and 2001. <br/><br>
The participants also delivered serum and urinary samples and answered questionnaires concerning maternal and paternal smoking during pregnancy. Data on maternal smoking was additionally assessed through the Swedish Medical Birth Register. Through a Swedish screening program for rubella, maternal serum samples were retrieved from the men's prenatal period. We analysed metabolites of phthalates as exposure markers both in the maternal sera and in urine and serum of the men. Associations between parental smoking during pregnancy as well as phthalate metabolite levels, and parameters of male reproductive function were studied.<br/><br>
In summary, we found no change in semen quality between 2000-2001 and 2008-2010. However, both maternal and paternal smoking during pregnancy were associated with reduced sperm counts in men whose other parent did not smoke. In addition, prenatal exposure to diethylhexyl phthalate (DEHP) and diisononyl phthalate (DiNP) appeared to be associated with decreased semen volume, and exposure to DiNP as well with smaller testicular size. Finally, adult exposure to DEHP and dibutyl phthalate (DBP) were associated with decreased progressive sperm motility, and DEHP exposure was also linked to a higher proportion of immature sperm. <br/><br>
Thus, although no change in semen quality appeared to have occurred in Swedish men during the last decade, parental smoking and prenatal and adult exposure to certain phthalates may play a role in the male reproductive function.},
  author       = {Axelsson, Jonatan},
  isbn         = {978-91-7619-124-8},
  issn         = {1652-8220},
  keyword      = {Semen analysis,maternal exposure,paternal exposure,smoking,phthalate},
  language     = {eng},
  pages        = {75},
  publisher    = {Molecular Reproductive Medicine},
  school       = {Lund University},
  series       = {Lund University, Faculty of Medicine Doctoral Dissertation Series},
  title        = {Reproductive function in young Swedish men - Time trend, prenatal and adult exposure to smoking and phthalates},
  volume       = {2015:45},
  year         = {2015},
}