ORIGINAL ARTICLE
Serum oestradiol levels in male partners of infertile couples J. Hagiuda, H. Ishikawa & K. Marumo Department of Urology, Ichikawa General Hospital, Tokyo Dental College, Ichikawa, Chiba, Japan
Keywords Body mass index—oestradiol—semen quality—testosterone Correspondence Jun Hagiuda, Department of Urology, Ichikawa General Hospital, Tokyo Dental College, Sugano 5-11-13, Ichikawa, Chiba 2728513, Japan. Tel.: +81 47 322 0151; Fax: +81 47 324 8539; E-mail: [email protected] Accepted: June 1, 2014 doi: 10.1111/and.12315
Summary A prospective clinical study was performed in the reproduction centre of Ichikawa General Hospital (Chiba, Japan) to investigate the relationship between sperm quality and serum oestradiol (E2) level in male partners of infertile couples. The semen parameters and blood samples were assessed in relation to several variables, including body mass index (BMI) and serum oestradiol (E2) levels. Four hundred and nine male partners of infertile couples aged 22–55 years (mean: 36.5 years) were referred to the reproduction centre. In total, 143 patients (35.0%) were included in the low E2 level group (18 pg ml 1 ≥ E2). Serum E2 levels were slightly correlated with testosterone levels, BMI and serum FSH levels. Total motile sperm count and morphology were decreased in low E2 level group. In multivariate analysis, serum testosterone, E2 levels, existence of varicocele and age were risk factors for decreased semen quality. Serum E2 might be associated with BMI, serum testosterone level and spermatogenesis.
Introduction A number of recent studies have reported on the declining semen quality and increasing population of infertile men (Irvine et al., 1996; Vanwaeleghem et al., 1996). However, more than 50% of cases of male infertility are idiopathic. In our clinic, we routinely monitor serum sex hormone levels and often encounter patients with abnormal hormone levels, including decreased oestradiol (E2) levels. Over the past several decades, the role of oestrogen in the male reproductive system has been studied. Aromatase converts testosterone into oestrogen. The oestrogen receptors (ERa and b) are present on testicular cells. In some animal models, oestrogen plays a role in proliferation and differentiation in spermatogenesis. Furthermore, knockout mice with these receptors were infertile (Carreau et al., 1999, 2003, 2006, 2009, 2010; Carreau & Hess, 2010). In humans, mutations in ERa (Toppari et al., 1996) and aromatase (Rochira & Carani, 2009) demonstrated the vital role of oestrogen in the male reproductive system. However, unlike the effects of age-dependent decreases in testosterone levels, the effects of decreased oestrogen levels caused by other factors in males are not well studied. To the best of our knowledge, no large-scale, population-based data analyses describing the relationship between seminal quality and decreased serum E2 level have been published. © 2014 Blackwell Verlag GmbH Andrologia 2014, xx, 1–5
This study aimed to analyse the sperm quality and serum hormone levels in male partners of infertile couples in Japan, and to determine the percentage of patients with low serum E2 levels and its association with sperm abnormalities. Materials and methods Patients Between May 2011 and December 2012, 409 couples with suspected infertility were referred to our reproduction centre. We defined the infertility according to World Health Organization (WHO) criteria (2000) as a noncontraceptive couple who does not achieve spontaneous pregnancy in 1 year. All of the male partners, aged 22–55 years (mean 36.5 5.80 years), were enrolled in our study. Written informed consent was obtained from all the participants before the start of the study. The weights and heights of the participants were measured in our laboratory and were used to calculate body mass index (BMI, weight [kg] divided by the height squared [m2]). Obesity was defined as BMI of at least 30 kg m 2 and more and overweight as a BMI of at least 25 kg m 2 by WHO. The volume of testes was assessed by punched-out orchidometer. Blood samples were taken 1
Serum oestradiol level and male fertility
from each individual between 09:00 and 12:00 h on the first day of the study, and the levels of total testosterone, luteinising hormone (LH), follicle-stimulating hormone (FSH) and E2 were measured. Serum E2 was measured by chemiluminescence immunoassay. The lower limit of detection was 10 pg ml 1, and the inter- and intra-assay coefficients of variation were 5.4% and 6.3% respectively. The male patients were categorised into two groups based on their serum E2 levels; the control group (E2 ≥ 19 pg ml 1) and the low E2 level group (E2 level ≤ 18 pg ml 1). The cut-off point was determined by minimum P value approach described by Mazumdar & Glassman (2000). Additionally, our cut-off point is consistent with the normal range based on the analysis of Japanese male volunteers (Iwasa et al., 2006). Iwasa et al. (2006) collected the sample from 59 healthy male volunteers and defined the normal range as log mean 2 standard deviation. Patients were excluded from the study if they were receiving systemic medication such as steroids or had a history of malignant, hepatic or neurological disease (necessitating brain surgery or psychiatric medication, which affects the pituitary hormones). Patients with azoospermia and varicocele were included in this study. Patients with azoospermia underwent testicular sperm extraction, and obstructive azoospermia was diagnosed when normal spermatogenesis was found histopathologically. Any other diagnoses, such as maturation arrest, germ cell aplasia or Sertoli cell-only syndrome, were classified as nonobstructive azoospermia. In the comparison of semen quality, the patients of obstructive azoospermia were excluded from analysis. Varicocele was diagnosed by physical examination and ultrasonography. We defined varicocele as grade 2 or 3 with retrograde flow at pampiniform plexus detected by Doppler ultrasonography. Semen collection Sperm quality was evaluated according to the guidelines of the WHO (2010) using semen samples obtained during masturbation. The findings showed normal values as follows: concentration ≥15 million ml 1, progressive motility ≥40% and morphology ≥4%. Total motile spermatozoon per ejaculation was calculated as semen volume 9 sperm concentration 9 percentage of progressive motile spermatozoon 9 1/100. In the univariate and multivariate analyses to evaluate the factor of poor semen quality, we defined the normal count of motile spermatozoon as at least 15.6 million. The semen samples were obtained twice during masturbation after 2–5 days of sexual abstinence; the sample that provided the best motile sperm count was used for the analyses. 2
J. Hagiuda et al.
Statistical analysis The statistical differences between the two groups were determined using the nonparametric Mann–Whitney Utest (P < 0.05, statistically significant). Spearman rank correlation was used to assess the correlation between the data of the two groups. The logistic regression model for univariate and multivariate analyses was used to evaluate relationships between total motile sperm count, the low E2 level and other factors. The chi-square test was used to compare the proportion of patients with azoospermia or varicocele between two groups. The analyses were performed using the JMP version 5.0 (SAS Institute, Cary, NC, USA) statistical software program. Results The sperm quality and serum examination results are shown in Table 1. Of the 409 patients in this study, 143 (35.0%) belonged to the low serum E2 level group. The age distribution and testicular volume were similar. Additionally, there was no difference in the proportion of varicocele and azoospermia between the groups. The Table 1 Comparison of body mass index, serum sex hormone levels and semen quality between the control and low oestradiol level groups
Case Nonobstructive azoospermia Germ cell aplasia Maturation arrest Sertoli cell only Obstructive azoospermia Varicocele Age (years) Testicular volume (ml) BMI (kg m 2) Case of overweight (%) Case of obesity (%) E2 (pg ml 1) LH (mIU ml 1) FSH (mIU ml 1) Testosterone (ng ml 1) TME (9108) Normal morphology (%)
Normal (19 pg ml 1≤)
Low E2 (18 pg ml 1≥)
266 11
143 5
0.960
6 4 1 8
2 3 0 5
0.979
P value
35 36.4 5.85 17.4 5.60
22 36.8 5.70 17.8 5.02
0.535 0.503 0.515
24.1 3.29 100 (37.6)
23.1 2.72 26 (18.2)
0.0176a
Serum oestradiol levels in male partners of infertile couples J. Hagiuda, H. Ishikawa & K. Marumo Department of Urology, Ichikawa General Hospital, Tokyo Dental College, Ichikawa, Chiba, Japan
Keywords Body mass index—oestradiol—semen quality—testosterone Correspondence Jun Hagiuda, Department of Urology, Ichikawa General Hospital, Tokyo Dental College, Sugano 5-11-13, Ichikawa, Chiba 2728513, Japan. Tel.: +81 47 322 0151; Fax: +81 47 324 8539; E-mail: [email protected] Accepted: June 1, 2014 doi: 10.1111/and.12315
Summary A prospective clinical study was performed in the reproduction centre of Ichikawa General Hospital (Chiba, Japan) to investigate the relationship between sperm quality and serum oestradiol (E2) level in male partners of infertile couples. The semen parameters and blood samples were assessed in relation to several variables, including body mass index (BMI) and serum oestradiol (E2) levels. Four hundred and nine male partners of infertile couples aged 22–55 years (mean: 36.5 years) were referred to the reproduction centre. In total, 143 patients (35.0%) were included in the low E2 level group (18 pg ml 1 ≥ E2). Serum E2 levels were slightly correlated with testosterone levels, BMI and serum FSH levels. Total motile sperm count and morphology were decreased in low E2 level group. In multivariate analysis, serum testosterone, E2 levels, existence of varicocele and age were risk factors for decreased semen quality. Serum E2 might be associated with BMI, serum testosterone level and spermatogenesis.
Introduction A number of recent studies have reported on the declining semen quality and increasing population of infertile men (Irvine et al., 1996; Vanwaeleghem et al., 1996). However, more than 50% of cases of male infertility are idiopathic. In our clinic, we routinely monitor serum sex hormone levels and often encounter patients with abnormal hormone levels, including decreased oestradiol (E2) levels. Over the past several decades, the role of oestrogen in the male reproductive system has been studied. Aromatase converts testosterone into oestrogen. The oestrogen receptors (ERa and b) are present on testicular cells. In some animal models, oestrogen plays a role in proliferation and differentiation in spermatogenesis. Furthermore, knockout mice with these receptors were infertile (Carreau et al., 1999, 2003, 2006, 2009, 2010; Carreau & Hess, 2010). In humans, mutations in ERa (Toppari et al., 1996) and aromatase (Rochira & Carani, 2009) demonstrated the vital role of oestrogen in the male reproductive system. However, unlike the effects of age-dependent decreases in testosterone levels, the effects of decreased oestrogen levels caused by other factors in males are not well studied. To the best of our knowledge, no large-scale, population-based data analyses describing the relationship between seminal quality and decreased serum E2 level have been published. © 2014 Blackwell Verlag GmbH Andrologia 2014, xx, 1–5
This study aimed to analyse the sperm quality and serum hormone levels in male partners of infertile couples in Japan, and to determine the percentage of patients with low serum E2 levels and its association with sperm abnormalities. Materials and methods Patients Between May 2011 and December 2012, 409 couples with suspected infertility were referred to our reproduction centre. We defined the infertility according to World Health Organization (WHO) criteria (2000) as a noncontraceptive couple who does not achieve spontaneous pregnancy in 1 year. All of the male partners, aged 22–55 years (mean 36.5 5.80 years), were enrolled in our study. Written informed consent was obtained from all the participants before the start of the study. The weights and heights of the participants were measured in our laboratory and were used to calculate body mass index (BMI, weight [kg] divided by the height squared [m2]). Obesity was defined as BMI of at least 30 kg m 2 and more and overweight as a BMI of at least 25 kg m 2 by WHO. The volume of testes was assessed by punched-out orchidometer. Blood samples were taken 1
Serum oestradiol level and male fertility
from each individual between 09:00 and 12:00 h on the first day of the study, and the levels of total testosterone, luteinising hormone (LH), follicle-stimulating hormone (FSH) and E2 were measured. Serum E2 was measured by chemiluminescence immunoassay. The lower limit of detection was 10 pg ml 1, and the inter- and intra-assay coefficients of variation were 5.4% and 6.3% respectively. The male patients were categorised into two groups based on their serum E2 levels; the control group (E2 ≥ 19 pg ml 1) and the low E2 level group (E2 level ≤ 18 pg ml 1). The cut-off point was determined by minimum P value approach described by Mazumdar & Glassman (2000). Additionally, our cut-off point is consistent with the normal range based on the analysis of Japanese male volunteers (Iwasa et al., 2006). Iwasa et al. (2006) collected the sample from 59 healthy male volunteers and defined the normal range as log mean 2 standard deviation. Patients were excluded from the study if they were receiving systemic medication such as steroids or had a history of malignant, hepatic or neurological disease (necessitating brain surgery or psychiatric medication, which affects the pituitary hormones). Patients with azoospermia and varicocele were included in this study. Patients with azoospermia underwent testicular sperm extraction, and obstructive azoospermia was diagnosed when normal spermatogenesis was found histopathologically. Any other diagnoses, such as maturation arrest, germ cell aplasia or Sertoli cell-only syndrome, were classified as nonobstructive azoospermia. In the comparison of semen quality, the patients of obstructive azoospermia were excluded from analysis. Varicocele was diagnosed by physical examination and ultrasonography. We defined varicocele as grade 2 or 3 with retrograde flow at pampiniform plexus detected by Doppler ultrasonography. Semen collection Sperm quality was evaluated according to the guidelines of the WHO (2010) using semen samples obtained during masturbation. The findings showed normal values as follows: concentration ≥15 million ml 1, progressive motility ≥40% and morphology ≥4%. Total motile spermatozoon per ejaculation was calculated as semen volume 9 sperm concentration 9 percentage of progressive motile spermatozoon 9 1/100. In the univariate and multivariate analyses to evaluate the factor of poor semen quality, we defined the normal count of motile spermatozoon as at least 15.6 million. The semen samples were obtained twice during masturbation after 2–5 days of sexual abstinence; the sample that provided the best motile sperm count was used for the analyses. 2
J. Hagiuda et al.
Statistical analysis The statistical differences between the two groups were determined using the nonparametric Mann–Whitney Utest (P < 0.05, statistically significant). Spearman rank correlation was used to assess the correlation between the data of the two groups. The logistic regression model for univariate and multivariate analyses was used to evaluate relationships between total motile sperm count, the low E2 level and other factors. The chi-square test was used to compare the proportion of patients with azoospermia or varicocele between two groups. The analyses were performed using the JMP version 5.0 (SAS Institute, Cary, NC, USA) statistical software program. Results The sperm quality and serum examination results are shown in Table 1. Of the 409 patients in this study, 143 (35.0%) belonged to the low serum E2 level group. The age distribution and testicular volume were similar. Additionally, there was no difference in the proportion of varicocele and azoospermia between the groups. The Table 1 Comparison of body mass index, serum sex hormone levels and semen quality between the control and low oestradiol level groups
Case Nonobstructive azoospermia Germ cell aplasia Maturation arrest Sertoli cell only Obstructive azoospermia Varicocele Age (years) Testicular volume (ml) BMI (kg m 2) Case of overweight (%) Case of obesity (%) E2 (pg ml 1) LH (mIU ml 1) FSH (mIU ml 1) Testosterone (ng ml 1) TME (9108) Normal morphology (%)
Normal (19 pg ml 1≤)
Low E2 (18 pg ml 1≥)
266 11
143 5
0.960
6 4 1 8
2 3 0 5
0.979
P value
35 36.4 5.85 17.4 5.60
22 36.8 5.70 17.8 5.02
0.535 0.503 0.515
24.1 3.29 100 (37.6)
23.1 2.72 26 (18.2)
0.0176a
