Biomedical subjects

Aleksander Giwercman

Publications and source records attributed to Aleksander Giwercman.

At least 19 recordsLinked to original sources

PubMed2006

Association between exposure to persistent organohalogen pollutants and epididymal and accessory sex gland function: multicentre study in Inuit and European populations.

Exposure to persistent organochlorine pollutants (POPs) may have negative impact on male reproductive function. We, therefore, investigated the association between serum levels of POPs and epididymal and accessory sex gland function. Serum levels of CB-153, p,p'-DDE and seminal markers of epididymal [neutral-alpha glucosidase (NAG)], prostatic [prostate specific-antigen (PSA)] and zinc, and seminal vesicle function (fructose) were measured from 135 Swedish fishermen and fertile men from Greenland (n=163), Warsaw, Poland (n=167) and Kharkiv, Ukraine (n=158). Multiple linear regression analyses, adjusting for potential confounders, were employed using both continuous and categorized exposure variables. Both exposure and outcome variables were log transformed. Considering the consistency between models with either continuous or categorized CB-153 levels, negative associations with the activity of NAG were found among Greenlandic men (mean difference 7.0 mU/ejaculate, 95% CI 3.0, 34), and in the aggregated cohort (mean difference 4.0 mU/ejaculate, 95% CI -0.2, 8.0). A positive association was observed between CB-153 and PSA as well as zinc among Kharkiv men. In the Swedish cohort, a negative association was found between CB-153 and fructose. In conclusion, the negative effects of POP on sperm motility, observed in the same study population might partly be caused by post-testicular mechanisms, involving a decreased epididymal function.

Adult↗

PubMed2006

Dioxin-like activities in serum across European and Inuit populations.

BACKGROUND: Persistent organic pollutants (POPs) such as polychlorinated dibenzo-p-dioxins/furans, polychlorinated biphenyls (PCBs) and organochlorine pesticides can cause a series of adverse effects on e.g. reproduction in animals and humans, many of which involve the aryl hydrocarbon receptor (AhR). The aim of the present study was to compare the integrated serum level of AhR mediated activity among European and Inuit populations, and evaluate whether the activity was associated to the selected POP markers, 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153) and 1,1-dichloro-2,2-bis(p-chlorophenyl)-ethylene (p,p'-DDE). METHODS: The study included 338 males from Greenland (Inuit's), Sweden, Warsaw (Poland) and Kharkiv (Ukraine). The AhR transactivity of serum extracts alone (AhRag) and competitive AhR activity (AhRcomp) upon co-exposure with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) were determined in the lipophilic serum fraction containing the POPs using the AhR mediated luciferase reporter Hepa1.12cR cell assay. RESULTS: The European groups showed higher median level of AhR-TEQ (TCDD toxic equivalents) compared to the Inuit's, whereas higher incidence of Inuits sample further induced AhRcomp activity. Neither AhRag nor AhR-TEQ were correlated to CB-153 or p,p'-DDE for any of the study groups. Multiple regressions showed a significant heterogeneity of association between the CB-153 and the AhRcomp across the study groups, and accordingly a negative association between AhRcomp and CB-153 was found for the Kharkiv group. CONCLUSION: No consistent correlation between AhR activities and two POP markers was found. Although the difference of AhRag between European and Inuit men could not be explained by CB-153 or p,p'-DDE levels alone, we believe that the variation of AhR serum activity reflects different pattern of POP exposure, genetics and/or life style factors.

Adolescent↗

PubMed2006

Frequent finding of the androgen receptor A645D variant in normal population.

BACKGROUND: The androgen receptor A645D mutation has been described in one patient with ambiguous genitalia and one boy with normal phenotype. OBJECTIVE: Because of this phenotypic variation, we screened a cohort of men from the general population (n = 293) as well as men with the following disorders of the genital tract for the mutation: men with prostate cancer (n = 89), testicular cancer (n = 87), and infertility (n = 103). We also investigated the influence of the polymorphic CAG and GGN repeats on the phenotypic outcome. RESULTS: The A645D variant was found in three men from the general population (1.0%). These men did not differ regarding testosterone or LH concentrations, compared with the rest of this population. In addition, two men with prostate cancer (2.3%) and one infertile man (1.0%) presented with the mutation. No statistical differences in frequency were noted between the study groups, and none of these individuals had any genital malformations. All men who presented with the mutation carried an extraordinarily short GGN repeat of 10 base triplets in combination with long CAG repeats of 26-28 (average 27.3). In contrast, men with GGN=10, but CAG less than 26 did not have the A645D mutation. A single-nucleotide polymorphism analysis revealed that the A645D variant has emerged from the most common haplogroup in our population. CONCLUSIONS: We conclude that the A645D mutation, which is present in 1% of the general Swedish population, is linked to GGN10 and long CAG repeats. Its effect on androgen receptor function is currently unknown.

Adolescent↗

PubMed2006

Xenoestrogenic activity in blood of European and Inuit populations.

BACKGROUND: Human exposure to persistent organic pollutants (POPs) is ubiquitous and found in all individuals. Studies have documented endocrine disrupting effects and impact on reproduction. The aim of the present study was to compare the level of xenoestrogenic activity in serum of groups with varying POP exposure, and to evaluate correlations to the POP biomarkers, 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153) and 1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene (p,p'-DDE). METHODS: The study included 358 men: Greenlandic Inuit's, Swedish fishermen, and Warsaw (Poland) and Kharkiv (Ukraine) inhabitants. Xenoestrogenicity of serum extracts alone (XER) and XER competitive (XERcomp) effect on 17beta-estradiol induced estrogen receptor (ER) transactivity were assessed in the hormone free, lipophilic serum fraction containing the POPs using the MVLN human breast cancer cell line. RESULTS: No agonistic XER activity was exhibited for Inuit serum samples, while 12 - 24% of the European samples had detectable agonistic XER activity. On the contrary, 71% of Inuit serum samples antagonized XERcomp compared to 7 - 30 % in the other regions. XER and XERcomp were not or weakly correlated to the two POP markers. XER activity of Inuit samples was negatively associated to levels of CB-153 and p,p'-DDE. For the Warsaw group a positive and negative correlation between XER and p,p'-DDE and estradiol equivalence level and CB-153 levels was found. CONCLUSION: No strong consistent association between xenoestrogenic net activity and the two POP markers was found. The results showed that the selected POP markers alone can not predict the integrated xenoestrogenic serum activity. Correlations to the POP markers were found at the extreme edge; the Inuit's and Warsaw study groups eliciting high frequency of samples with ER antagonistic and agonistic activity, respectively. We suggest that the variation in xenoestrogenic serum activity reflects differences in POP exposure mixture, genetic factors and/or life style factors.

Adolescent↗

PubMed2006

Semen quality and exposure to persistent organochlorine pollutants.

BACKGROUND: Inconsistent results have been found in previous human studies on male reproductive toxicity of persistent organochlorine pollutants. The majority of studies have been conducted among selected populations of infertility clients or among occupational cohorts including a limited number of participants. METHODS: We conducted a cross-sectional study of semen quality and serum concentration of 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153) and 1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene (p,p'-DDE) among 763 men. We included men from all regions in Greenland (n = 194), fishermen from Sweden (n = 185), inhabitants of the city of Kharkiv, Ukraine (n = 195), and inhabitants of the city of Warsaw, Poland (n = 189). Blood samples were analyzed for CB-153 and p,p'-DDE using gas chromatography-mass spectrometry and adjusted for serum lipids. RESULTS: Sperm concentration was not impaired with increasing serum CB-153 or p,p'-DDE levels in any of the separate groups or overall. Similarly, the proportion of morphologically normal sperm was not associated with either CB-153 or p,p'-DDE blood concentration. However, sperm motility was inversely related to CB-153 concentration in Greenland and the Swedish fishermen population. Across all 4 regions, the sperm motility decreased on average by 3.6% (95% confidence interval = 1.7% to 5.6%) per one-unit increase in the log of blood CB-153 (ng/g lipid). The concentration of p,p'-DDE was negatively associated with sperm motility in the Greenlandic population and in the compiled dataset. CONCLUSION: Adult exposure to persistent organochlorine pollutants within the ranges observed in the present study is not likely to cause reduction in sperm concentration or morphology. However, higher exposure may be associated with impaired sperm motility.

Cross-Sectional Studies↗

PubMed2006

Remarkably low incidence of hypospadias in Greenland despite high exposure to endocrine disrupters; possible protective effect of androgen receptor genotype.

Endocrine disrupters, such as persistent organohalogen pollutants (POPs) may cause hypospadias, which is a common congenital anomaly in males, affecting 0.2-0.7%. We hypothesized that hypospadias incidence would be high among Greenlanders, who are one of the most POP exposed populations on earth through consumption of contaminated sea mammals. Interestingly, among the 11 076 boys born in Greenland 1982-2002, only two cases of hypospadias were noted (incidence 0.02%; 95% CI: 0.002-0.06). Normal male sexual differentiation is dependent on the androgen receptor (AR). AR function is regulated by polymorphic repeats of CAG and GGN trinucleotide bases. In Greenland 85% were carriers of GGN=23, which in a previous report was less frequent in patients with hypospadias than in the general population. This finding indicates that AR genotype could contribute to a genetic predisposition in Greenlanders, who despite one of the worlds highest body burden of POPs, seem to be protected from hypospadias.

Endocrine Disruptors↗

PubMed2006

Ethnic differences in occurrence of TDS-- genetics and/or environment?

It has been hypothesized that poor semen quality, testis cancer, undescended testis and hypospadias are symptoms of one underlying entity, the so-called testicular dysgenesis syndrome (TDS). TDS was suggested to be a result of disruption of embryonal programming and gonadal development during foetal life and as aetiological factor, an impact of adverse environmental factors such as hormone disrupters, probably acting upon a susceptible genetic background, was suggested. Extensive studies considering the risk of TDS-related diseases in Denmark compared with Finland, showed higher sperm counts and lower risk of cryptorchidism and testicular cancer among Finns. However, when comparing these two populations, the question arises, to which degree this difference might be due to discrepancy in genetic background. A more obvious example of the impact of genetic factors on the risk of TDS concerns Afro-Americans having significantly lower incidence of testicular cancer when compared with Caucasians living in the USA. A yet unexplored scenario is a possible interaction between genetic and environmental/lifestyle-related factors, certain genotypes making individuals more susceptible to adverse exogenous exposures. Studying such interactions has biological, epidemiological and public health-related implications. It will help us to understand the background for the defects in male reproductive organs, facilitate proper design of epidemiological studies and add to identifying individuals susceptible to certain environmental and lifestyle-related hazards. Such 'susceptibility genes' need to be identified, those involved in the synthesis, action and metabolism of sex steroids being strong candidates.

Cryptorchidism↗

PubMed2006

Impact of PCB and p,p'-DDE contaminants on human sperm Y:X chromosome ratio: studies in three European populations and the Inuit population in Greenland.

OBJECTIVE: Recent studies indicate that persistent organohalogen pollutants (POPs) may contribute to sex ratio changes in offspring of exposed populations. Our aim in the present study was to investigate whether exposure to 2,2 ,4,4 ,5,5 -hexachlorobiphenyl (PCB-153) and dichlorodiphenyldichloroethene (p,p -DDE) affects sperm Y:X chromosome distribution. SUBJECTS AND METHODS: We obtained semen and blood for analysis of PCB-153 and p,p -DDE levels from 547 men from Sweden, Greenland, Poland (Warsaw), and Ukraine (Kharkiv), with regionally different levels of POP exposure. The proportion of Y- and X-chromosome-bearing sperm in the semen samples was determined by two-color fluorescence in situ hybridization analysis. RESULTS: Swedish and Greenlandic men had on average significantly higher proportions of Y sperm (in both cohorts, 51.2%) and correspondingly higher lipid-adjusted concentrations of PCB-153 (260 ng/g and 350 ng/g, respectively) compared with men from Warsaw (50.3% and 22 ng/g) and Kharkiv (50.7% and 54 ng/g). In the Swedish cohort, log-transformed PCB-153 and log-transformed p,p -DDE variables were significantly positively associated with Y-chromosome fractions (p-values 0.04 and <0.001, respectively). On the contrary, in the Polish cohort PCB-153 correlated negatively with the proportion of Y-bearing fraction of spermatozoa (p=0.008). CONCLUSIONS: The present study indicates that POP exposure might be involved in changing the proportion of ejaculated Y-bearing spermatozoa in human populations. Intercountry differences, with different exposure situations and doses, may contribute to varying Y:X chromosome ratios.

Chromosomes, Human, X↗

PubMed2005

Inter-population variations in concentrations, determinants of and correlations between 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153) and 1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene (p,p'-DDE): a cross-sectional study of 3161 men and women from Inuit and European populations.

BACKGROUND: The study is part of a collaborative project (Inuendo), aiming to assess the impact of dietary persistent organochlorine pollutants (POPs) on human fertility. The aims with the present study are to analyze inter-population variations in serum concentrations of 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153) and 1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene (p,p'-DDE), to assess inter-population variations in biomarker correlations, and to evaluate the relative impact of different determinants for the inter-individual variations in POP-biomarkers. METHOD: In study populations of 3161 adults, comprising Greenlandic Inuits, Swedish fishermen and their wives, and inhabitants from Warsaw, Poland and Kharkiv, Ukraine, serum concentrations of CB-153 and p,p'-DDE, were analysed by gas chromatography-mass spectrometry. RESULTS: The median serum concentrations of CB-153 were for male and female Inuits 200 and 110, for Swedish fishermen 190 and their wives 84, for Kharkiv men and women 44 and 27, and for Warsaw men and women 17 and 11 ng/g lipids, respectively. The median serum concentrations of p,p'-DDE were for Kharkiv men and women 930 and 650, for male and female Inuits 560 and 300, for Warsaw men and women 530 and 380, and for Swedish fishermen 240 and their wives 140 ng/g lipids, respectively. The correlation coefficients between CB-153 and p,p'-DDE varied between 0.19 and 0.92, with the highest correlation among Inuits and the lowest among men from Warsaw. Men had averagely higher serum concentrations of CB-153 and p,p'-DDE, and there were positive associations between age and the POP-biomarkers, whereas the associations with BMI and smoking were inconsistent. Dietary seafood was of importance only in the Inuit and Swedish populations. CONCLUSION: CB-153 concentrations were much higher in Inuits and Swedish fishermen's populations than in the populations from Eastern Europe, whereas the pattern was different for p,p'-DDE showing highest concentrations in the Kharkiv population. The correlations between the POP-biomarkers varied considerably between the populations, underlining that exposure sources differ and that the choice of representative biomarkers of overall POP exposure has to be based on an analysis of the specific exposure situation for each population. Age and gender were consistent determinants of serum POPs; seafood was of importance only in the Inuit and Swedish populations.

Adult↗

PubMed2005

Fertility in four regions spanning large contrasts in serum levels of widespread persistent organochlorines: a cross-sectional study.

BACKGROUND: Persistent organochlorine pollutants (POPs) may interfere with reproductive function but direct evidence in humans is very limited. METHODS: Fertility was examined in four regions with contrasting blood levels of POPs. Pregnant women and their partners in Warsaw (Poland), Kharkiv (Ukraine) and Greenland were consecutively enrolled during antenatal visits. Swedish fishermen and their spouses were recruited separately and independently of current pregnancy. Lipid adjusted serum concentrations of 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153) and 1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene (DDE) were available for both partners. Time to pregnancy interviews were obtained among 2269 women and 798 men provided a semen sample. RESULTS: Inuits had high levels of both POP markers, Swedish fishermen were high in CB-153 but low in DDE, men from Kharkiv were high in DDE and low in CB-153 while men from Warsaw were low in CB-153 and had intermediate DDE levels. Compared to Warsaw couples, fecundability was reduced among couples from Kharkiv [adjusted fecundability ratio (FR) 0.64 (95% CI 0.5-0.8)] and elevated in Swedish fishermen families [FR 1.26 (95% CI 1.0-1.6)]. Adjusted geometric means of sperm counts and morphology did not differ between regions while sperm motility was higher in men living in Warsaw. CONCLUSION: We observed regional differences in time to pregnancy and sperm motility that may be related to regional differences in POP blood levels, but other interpretations are also plausible. In particular, differences in access to safe contraception and in the prevalence of contraceptive failures are most likely to bias comparisons of time to pregnancy.

Biomarkers↗

PubMed2005

Blood levels of free-PSA but not complex-PSA significantly correlates to prostate release of PSA in semen in young men, while blood levels of complex-PSA, but not free-PSA increase with age.

BACKGROUND: The proportion of free- and complex-prostate specific antigen (PSA) in serum is used for differentiating between benign and malignant prostate disease. To further understand the physiological relationship between PSA in seminal plasma and blood, we have analyzed free-PSA (fPSA) and complex-PSA (cPSA) in blood and PSA in seminal plasma in young healthy men. We also compared age-related changes of PSA-forms in blood from young versus older men. METHODS: Total-PSA (tPSA), fPSA, and cPSA were measured in (i) blood and semen from 289 male conscripts (mean age 18.1 years) and in (ii) blood from a representative population of 1,389 men (mean age 46.5 years) without diagnosis of prostate cancer (PCa) during long-term follow-up. RESULTS: fPSA in serum (r = 0.40, P < 0.0001) but not cPSA (r = 0.09, P = 0.11), correlates to PSA in seminal fluid. fPSA levels in blood in young (geometric mean: 0.20 ng/ml) versus middle-aged men (geometric mean: 0.18 ng/ml) was not different (P = 0.06), whereas cPSA in middle-aged men (geometric mean: 0.38 ng/ml) was higher (P < 0.0001) than in young men (geometric mean: 0.28 ng/ml). CONCLUSIONS: fPSA in blood, but not cPSA, is associated to PSA in semen ( approximately 17% co-variation). In blood cPSA, but not fPSA, increase with age in healthy men, which may reflect an increasing incidence of prostate disease.

Adolescent↗

PubMed2005

Reduced risk of prostate cancer in men who are childless as compared to those who have fathered a child: a population based case-control study.

Androgens are believed to play a major role in the etiology of prostate cancer, but studies of sex-hormone exposure in relation to risk for prostate cancer have been inconclusive. Male fertility may be an indicator of long-term androgen status. To study the role of testicular function in prostate cancer development, we have assessed number of biological children in relation to risk for this malignancy. We carried out a population-based case-control study with retrospective ascertainment of cases occurring in Sweden between 1958-98. In total, 48,850 cases of prostate cancer were identified through the nation-wide Cancer Registry. For each case, one control, matched by year of birth, was randomly selected from the Swedish population. Information on offspring was obtained from the Swedish Multi-Generation Registry. We estimated odds ratios (OR) and 95% confidence intervals (CI) for the association between number of offspring and risk for subsequent prostate cancer. Being childless or having fathered one child only were associated with reduced risks for prostate cancer compared to having fathered 2 or more children (OR = 0.83; 95% CI = 0.81-0.86 and OR = 0.93; 95% CI = 0.90-0.96, respectively). There was no further change in risk associated with fathering of more than 2 children. The risk for prostate cancer is reduced among childless men. A dysfunctioning reproductive apparatus fueling to a lesser extent prostatic growth, could be a plausible mechanism of this association.

Aged↗

PubMed2005

The RsaI polymorphism in the estrogen receptor-beta gene is associated with male infertility.

CONTEXT: Hypospadias, cryptorchidism, testicular cancer, and low semen quality have been proposed as being parts of the testicular dysgenesis syndrome (TDS) hypothetically due to changes in the androgen-estrogen balance in utero. Estrogens and estrogen receptors (ERs) play a role in regulating testicular function. ERbeta contains two silent polymorphisms, RsaI (G1082A) and AluI (G1730A). OBJECTIVE: We investigated the significance of these polymorphisms in the etiology of disorders being part of TDS. SETTING: The patients were recruited consecutively through university hospital clinics. PARTICIPANTS: Four groups of Caucasian patients were included: 106 men from infertile couples with a sperm concentration less than 5 x 10(6) spermatozoa/ml, 86 testicular cancer patients, 51 boys with hypospadias, and 23 cases with cryptorchidism. Military conscripts (n = 186) with sperm concentration higher than 5 x 10(6) spermatozoa/ml served as controls. MAIN OUTCOME MEASURES: ERbeta polymorphisms RsaI and AluI were determined by allele-specific PCR. In addition, reproductive hormone analyses were performed in controls and infertile men. RESULTS: Compared with the controls, the frequency of the heterozygous RsaI AG-genotype was three times higher in infertile men (13.2 vs. 4.3%; P = 0.01). The heterozygous RsaI AG genotype was associated with an approximately 20% reduction in LH concentration, compared with the wild-type RsaI GG genotype in both controls and infertile men. Subjects with testicular cancer, hypospadias, or cryptorchidism did not differ from controls regarding the frequency of any of the polymorphisms. CONCLUSIONS: Polymorphisms in ERbeta may have modulating effects on human spermatogenesis. The phenotype of TDS seems to be, at least partly, determined by the genotype.

Adult↗

PubMed2005

Exposure to persistent organochlorine pollutants associates with human sperm Y:X chromosome ratio.

BACKGROUND: During the last decades, there has been concern that exposure to endocrine disruptors, such as persistent organochlorine pollutants (POPs), may contribute to sex ratio changes in offspring of exposed populations. METHODS: To investigate whether exposure to 2,2'4,4'5,5'-hexachlorobiphenyl (CB-153) and dichlorodiphenyl dichloroethene (p,p'-DDE) affect Y:X chromosome proportion, semen of 149 Swedish fishermen, aged 27-67 years, was investigated. The men provided semen and blood for analysis of hormone, CB-153 and p,p'-DDE levels. The proportion of Y- and X-chromosome bearing sperm in semen samples was determined by two-colour fluorescence in situ hybridization (FISH) analysis. RESULTS: Log transformed CB-153 as well as log transformed p,p'-DDE variables were both significantly positively associated with Y chromosome fractions (P-values = 0.05 and <0.001, respectively). Neither age, smoking nor hormone levels showed any association with Y-chromosome fractions. CONCLUSIONS: This is the first study to indicate that exposure to POPs may increase the proportion of ejaculated Y-bearing spermatozoa. These data add to the growing body of evidence that exposure to POPs may alter the offspring sex ratio.

Adult↗

PubMed2005

The 5alpha-reductase type II A49T and V89L high-activity allelic variants are more common in men with prostate cancer compared with the general population.

OBJECTIVES: To compare men with prostate disease with those from the general population regarding polymorphisms in the androgen receptor gene and in the 5alpha-reductase II (SRD5A2) gene. MATERIALS AND METHODS: The SRD5A2 polymorphisms A49T, V89L and R227Q, the androgen receptor CAG and GGN repeats and sex hormone status was investigated in men with prostate cancer (CaP) (n=89), benign prostate hyperplasia (n=45) and healthy military conscripts (n=223). RESULTS: The SRD5A2 high-activity allele variants A49T AT and V89L LL were more frequent in CaP-patients compared to general population, p=0.026 and p=0.05, respectively. CaP progression was, however, independent of SRD5A2 variants. In contrary, men with GGN<23 had a higher risk of dying from the disease than their counterparts with longer repeats. CONCLUSIONS: Men with CaP were more often genetically predisposed to a higher enzymatic activity in the turn over from T to DHT compared to the general population. In our population, androgen receptor genotype affected CaP outcome.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗

PubMed2005

Urinary phthalate metabolites and biomarkers of reproductive function in young men.

BACKGROUND: High exposure to phthalates, which are ubiquitous contaminants, has been shown in animal studies to produce detrimental effects on male reproductive functions. A recent study in humans reported dose-response relations between low phthalate levels in urine and human semen parameters, which raises the question whether humans are more sensitive to phthalate exposure than animals. METHODS: Urine, serum, and semen samples were collected from 234 young Swedish men at the time of their medical conscript examination. Semen volume, sperm concentration, and motility were measured, together with sperm chromatin integrity (sperm chromatin structure assay) and biochemical markers of epididymal and prostatic function. We analyzed reproductive hormones in serum, and mono ethyl phthalate (MEP), mono ethylhexyl phthaltale (MEHP), mono benzyl phthalate (MBzP), mono butyl phthalate (MBP), and phthalic acid in urine. RESULTS: For MBP, MBzP, and MEHP, no clear pattern of associations were observed with any of the reproductive biomarkers. Subjects within the highest quartile for MEP had fewer motile sperm (mean difference = 8.8%; 95% confidence interval = 0.8-17), more immotile sperms (8.9%; 0.3-18), and lower luteinizing hormone values (0.7 IU/L; 0.1-1.2), but there was no suggestion of harmful effects for most other endpoints. Phthalic acid actually was associated with improved function, as measured by several markers. CONCLUSIONS: The observed weak associations between 1 phthalate biomarker and impairment of a few aspects of reproductive function biomarkers were not consistent with results from a recent U.S. study. It is not yet possible to conclude whether phthalate exposure may reflect a hazard for human male reproduction.

Adolescent↗

PubMed2005

Quality control workshops in standardization of sperm concentration and motility assessment in multicentre studies.

Semen quality has been reported to vary markedly between different regions. To properly assess the differences among countries a minimization of the variation among centres in the assessments of sperm quality is essential. We here report on the training and two subsequent follow-up workshops on assessments of sperm concentration and motility. A total of 26 fresh ejaculates were analysed by four persons who were collecting these data in a multicentre study on sperm quality. In addition, two trained technicians from one of the laboratories analysed the samples. At the first training workshop, the median coefficient of variation among centres in sperm concentration was 27.7%, but decreased markedly to 17.0% at the second workshop and 8.1% (p = 0.048) at the third workshop. The CV for evaluation of the proportion of progressive motile sperm decreased less and not statistically significant from 16.5 to 14.1% and 11.0% (p = 0.94). At the third workshop there were no statistical significant differences among centres in assessments of sperm concentration or motility (p > 0.57). Furthermore the coefficient of variation in assessments of sperm concentration and motility among centres were at the same level as between two trained technicians (p > 0.72). This study indicates that training and subsequent follow-up workshops can assure minimum variability among centres in assessments of sperm concentration and motility.

Analysis of Variance↗

PubMed2005

Sperm concentration in Latvian military conscripts as compared with other countries in the Nordic-Baltic area.

Recent studies of semen quality in men from the general population gave rise to the hypothesis of an East-West gradient in semen quality in the Nordic-Baltic area, with the highest sperm counts in Estonia, Lithuania and Finland, and the lowest in Denmark (30% difference in mean concentration). Genetic, lifestyle-related and environmental factors - alone or in combination - were suggested to be responsible for these differences. The aim of this study was to assess sperm concentration in men from the general population in Latvia and to investigate the impact of ethnic and lifestyle-related factors on this marker of male reproductive health. A total of 133 military conscripts from Latvia were investigated. We found that sperm counts among Latvian adolescents were at the same level (mean 74, median 63 x 10(6)/mL) as those previously reported from Estonia, Lithuania and Finland. Sperm concentration was somewhat higher than in Sweden without reaching the level of statistical significance (mean difference 3 x 10(6)/mL; 95% CI: -10, 16 x 10(6)/mL), and statistically significantly higher that in Denmark (mean difference: 17 x 10(6)/mL; 95% CI: 5, 2 x 10(6)/mL). The study also revealed an impact of ethnic factors on sperm numbers. Sperm concentration was significantly higher in men with both parents born in Latvia (77 +/- 60 x 10(6)/mL), compared with men with both parents born outside Latvia (55 +/- 45 x 10(6)/mL, p = 0.03).

Adult↗