Comparative rates of androgen production and metabolism in Caucasian and Chinese subjects

The efficacy of and user satisfaction with different antiandrogens in Chinese transgender women

Objective

Cyproterone acetate (CPA) and spironolactone (SPL) are different antiandrogens in gender-affirming hormone therapy (GAHT) for transgender women. Few studies have evaluated their efficacy and user satisfaction, especially among East Asians. This study aimed to evaluate these aspects in Chinese transgender women.

Methods

Data were collected retrospectively from transgender women visiting the Peking University Third Hospital from 2012 to 2021. From 639 people identified as transgender women, 151 of them (80 using CPA and 71 using SPL, 16 to 40-year-old) under stable GAHT ≥6 months were enrolled. Total testosterone levels and visual analogue scale (VAS)-based satisfaction scores were evaluated.

Results

No difference was observed in age between the CPA and SPL groups (median [IQR], 22 [20-24] years and 23 [20-26] years, respectively). The duration of GAHT was longer in CPA group than in SPL group (18 [10-32] months vs. 12 [8-21] months, p = 0.009). Total testosterone levels were significantly lower with CPA treatment (25 mg/d) than with SPL treatment (100 mg/d) (median [IQR]: 0.7 [0.7-2.1] nmol/L vs. 13.0 [6.0-17.8] nmol/L, p < 0.001). The proportion of total testosterone levels reaching the recommended range was significantly higher in CPA group than in SPL group (75.0% vs. 11.3%, p < 0.001). VAS-based satisfaction scores for erection decreased and figure feminization were higher in CPA group than in SPL group, which remained unchanged after adjusting for age, treatment duration, estradiol dose, and comorbid mental disorders (p < 0.05). The prolactin levels were higher in CPA group than in SPL group (18.9 [11.8-28.1] ng/ml vs. 11.8 [7.9-18.4] ng/ml, p < 0.001). No severe safety events were reported in both groups.

Conclusion

In Chinese transgender women, CPA was more effective than SPL in lowering testosterone levels. Additionally, VAS scores indicated greater satisfaction with erection decreased and figure feminization using CPA compared to SPL.

Polypharmacy, Gender Disparities, and Ethnic and Racial Predispositions in Long QT Syndrome: An In-Depth Review

Long QT syndrome (LQTS) is a complex disorder of cardiac electrophysiology. It is characterized by delayed myocardial polarization leading to QT prolongation and alterations on the ST segment and T wave visible on electrocardiogram (ECG). Syncope is a common manifestation, and torsade de pointes (TdP) can lead to sudden cardiac death. Three major LQTS genes (KCI31, KCNH2, and SCN5) lead to most of the cases of LQTS. Lifestyle modifications, beta blockers, and implantable cardioverter defibrillator (ICD) placement are the main treatments for LQTS. Polypharmacy, including QT-prolonging drugs, has been shown to worsen LQTS. The impact on potassium channels and the human ether-a-go-go-related gene (hERG) is the mechanism behind the QT interval prolongation caused by these medications. There is an increased incidence of LQTS among African-American men and women as compared to Caucasians. Women with LQTS tend to have a higher mortality rate from the condition, especially during menstruation and shortly after giving birth. Genetic testing is reserved to those patientswho exhibit either a strong clinical index of suspicion or experience persistent QT prolongation despite their lack of symptoms. Knowing the genetics, racial, and gender discrepancies can help improve patient management and a better comprehension on each case. Proper understanding of how ion channels function and their interaction with medications will lead to a better comprehension and to develop effective forms to treat those patients.

Detectability of oxandrolone, metandienone, clostebol and dehydrochloromethyltestosterone in urine after transdermal application

Situations of both, intentional as well as inadvertent or accidental doping, necessitate consideration in today's doping controls, especially in the light of the substantial consequences that athletes are facing in case of so-called adverse analytical findings. The aim of this study was to investigate, whether a transdermal uptake of doping substances would be possible. In addition to the period of detectability of the particular substances or respective characteristic metabolites, the possibility of deducing the route of administration by metabolite patterns was also assessed. Twelve male subjects were included in the study. Four common anabolic androgenic steroids (AAS) were dissolved in dimethylsulfoxide (DMSO) to facilitate transdermal administration on different skin regions. One half of the test persons received only oxandrolone (17α-methyl-2-oxa-4,5α-dihydrotestosterone), the other half was applied a mixture of oxandrolone, metandienone (17β-hydroxy-17-methylandrosta-1,4-dien-3-one), clostebol (4-chlorotestosterone-17β-acetate) and dehydrochloromethyltestosterone (DHCMT). Urine samples were collected 1 hour, 6 hours and one sample per day for the next 14 consecutive days. Measurements were conducted on a GC-MS/MS or LC-MS/MS system. Substance findings were obtained at least 1 day after application on nearly all skin locations. The results indicated inter-individual variability in detection windows, also varying between the different analytes and possible impact of skin location and skin thickness, respectively. Nevertheless, a rapid and rather long detectability of all substances (or respective metabolites) was given, in some cases within hours after administration and for up to 10-14 days. Hence, the transdermal application or exposure to the investigated AAS is a plausible scenario that warrants consideration in anti-doping.

Pituitary as a Source of HCG: Residual Levels After Bilateral Testicular Tumor Removal

Context. Challenging clinical scenario in which elevated β-human chorionic gonadotropin (HCG, subsequently termed HCG) levels suggested occult tumor metastases after removal of bilateral testicular cancers and metastases from them and as well as after chemotherapy. Case Report. A 22-year-old male, post excision of bilateral testicular tumors, who had no imaging or clinical evidence of residual tumor but an elevated HCG raising the question of the presence and location of occult tumor metastases. Clinical Questions. Does luteinizing hormone (LH) cross-react with HCG in current assays? What levels of testosterone and estradiol are necessary to suppress LH and follicle-stimulating hormone (FSH) in a male patient with bilateral orchiectomy, and therefore lacking inhibin? Does the pituitary secrete HCG and under what circumstances? Assessment. Current HCG assays no longer cross-react with LH as did prior assays, but the presence of heterophile antibodies and other factors such as biotin can still cause false positive HCG levels. In the chronic post-orchiectomy state, the pituitary is relatively resistant to LH and FSH suppression by testosterone. The pituitary secretes HCG in very small amounts unless interruption of negative feedback results in high LH and FSH whereupon HCG levels become elevated. Clinical Conclusion. A GnRH antagonist suppressed both LH and HCG in this patient indicating that the elevated HCG was secreted by the pituitary and not by occult tumor metastases. Further credence for this conclusion resulted from the lack of a progressive increase in HCG levels over a 4-year period of follow-up and from no evidence of metastatic tumors on serial imaging.

Hormonal, chemical and thermal inhibition of spermatogenesis: contribution of French teams to international data with the aim of developing male contraception in France

Since the 1970s, international research on male contraception has been actively pursued. Hormonal and non-hormonal methods (thermal, chemical) have been tested, leading to clinical trials of interest to thousands of men and couples. The results showed that it was possible to develop methods of male contraception that inhibited spermatogenesis with good contraceptive efficacy. However, their side effects (mainly loss of libido), poorly accepted modes of administration, and the high frequency of poor responders prevented their widespread use. Based on earlier initiatives, new avenues were explored and significant progress was achieved, allowing the reasoned use of male contraception. For 40 years, several French teams have played an important role in this research. The aim of this paper is to outline the history and the progress of the experimental and clinical works of these teams who addressed hormonal, chemical and thermal approaches to male contraception. These approaches have led to a better comprehension of spermatogenesis that could be useful in fields other than male contraception: effects of toxic compounds, fertility preservation.

Racial Differences in Electrocardiographic Characteristics and Prognostic Significance in Whites Versus Asians

Background

Racial differences in electrocardiographic (ECG) characteristics and prognostic significance among Whites and Asians are not well described.

Methods and Results

We studied 2677 White Framingham Heart Study participants (57% women) and 2972 Asian (64% women) Singapore Longitudinal Aging Study participants (mean age 66 years in both) free of myocardial infarction or heart failure. Racial differences in ECG characteristics and effect on mortality were assessed. In linear regression models, PR interval was longer in Asians compared with Whites (multivariable‐adjusted β±SE 5.0±1.4 ms in men and 6.6±0.9 ms in women, both P<0.0006). QT interval was shorter in Asian men (β±SE −6.2±1.2 ms, P<0.0001) and longer in Asian women (β±SE 3.6±0.9 ms, P=0.02) compared to White men and women, respectively. Asians had greater odds of having ECG left ventricular hypertrophy (LVH) compared with Whites (odds ratio [OR] 3.56, 95% confidence interval [CI] 1.36–9.35 for men, OR 1.93, 95% CI 1.35–2.76 for women, both P<0.02). Over a mean follow‐up of 11±3 years in Framingham and 8±3 years in Singapore, mortality rates were 24.5 and 13.4 per 1000 person‐years among Whites and Asians, respectively. In Cox models, the presence of LVH had a greater effect on all‐cause mortality in Asians compared with Whites (hazard ratio [HR] 2.66, 95% CI 1.83–3.88 vs HR 1.30, 95% CI 0.90–1.89, P for interaction=0.02).

Conclusion

Our findings from two large community‐based cohorts show prominent race differences in ECG characteristics between Whites and Asians, and also suggest a differential association with mortality. These differences may carry implications for race‐specific ECG reference ranges and cardiovascular risk.

Dynamic alteration of serum testosterone with aging: a cross-sectional study from Shanghai, China

BACKGROUND

Level of the testosterone in a man's life span is very important. Studies on the serum testosterone concentrations in different age groups of healthy men were controversial. The aim of this study was to investigate dynamic changes of serum reproductive hormones with aging in healthy Chinese male and to compare its correlation with age.

METHODS

Total of 1,093 healthy Chinese men from Shanghai aged from 20 to 87  years old was enrolled in the study. Concentrations of serum total testosterone (T), luteinizing hormone (LH) and sex hormone binding globulin (SHBG) were quantified by EIA. Testosterone secretion index (TSI) and free testosterone index (FTI) were then calculated. Data were analyzed by SPSS program. Non-parametric tests and univariate linear regression analyses were used.

RESULTS

The 1,039 male participants were grouped into 12 groups by 5-year apart for each group. Significant differences in T, LH, SHBG, FTI and TSI were found between the 12 different age groups. Average of serum total T was 15.36 ± 4.86 nmol/L; LH was 4.76 ± 2.76 IU/L, SHBG was 32.61 ± 17.24 nmol/L. Compared to age 20 ~ 24 group, serum T level of age 35 ~ 39, 40 ~ 44, 45 ~ 49, 50 ~ 54, and 55 ~ 59 was significantly decreased (p < 0.05). Intriguingly, however, serum T level of age 60 or older did not significantly reduced compared to the age of 20 ~ 24 group. Serum LH and SHBG were positively correlated with aging (p <0.01), while TSI and FTI were negatively correlated with aging (p <0.01). In addition, BMI was negatively and significantly correlated with levels of T (r = -0.585, p < 0.001), LH (r = -0.090, p < 0.001), SHBG (r = - 1.817, p < 0.001), and TSI (r = - 0.104, p < 0.001), but positively and significantly correlated with FTI level (r = 0.011, p < 0.001).

CONCLUSION

Serum total testosterone fluctuated with aging in adult men, and FTI and TSI decreased gradually with aging. While age was not significantly correlated with T level, BMI was significantly and negatively correlated with T level, suggesting body weight may affect testosterone level.

Testosterone level in men with type 2 diabetes mellitus and related metabolic effects: A review of current evidence

A significant proportion of patients with type 2 diabetes mellitus have a low testosterone level relative to reference ranges based on healthy young men. Only a small number of these patients suffer from classical hypogonadism as a result of recognizable hypothalamic-pituitary-gonadal axis pathology. The cut-off value of the serum testosterone level in men without obvious hypothalamic-pituitary-gonadal axis pathology is controversial. It is unclear to what extent a low serum testosterone level causally leads to type 2 diabetes and/or the metabolic syndrome. From a theoretical standpoint, there can be complex interactions among the hypothalamic-pituitary-gonadal axis, body composition and insulin resistance, which can be further influenced by intrinsic and extrinsic factors to give rise to metabolic syndrome, glucose intolerance, and low-grade inflammation to increase the risk of cardiovascular disease. Although a low serum testosterone level frequently coexists with cardiometabolic risk factors and might serve as a biomarker, more studies are required to clarify the causal, mediating or modifying roles of low serum testosterone level in the development of adverse clinical outcomes. Currently, there are insufficient randomized clinical trial data to evaluate the effects of testosterone replacement therapy on meaningful clinical outcomes. The risk-to-benefit ratio of testosterone therapy in high-risk subjects, such as those with type 2 diabetes, also requires elucidation. The present article aims to review the current evidence on low serum testosterone levels in patients with type 2 diabetes, and its implications on cardiovascular risk factors, metabolic syndrome and adverse clinical outcomes.

Case-control and prospective studies of dietary α-linolenic acid intake and prostate cancer risk: a meta-analysis

OBJECTIVE

α-Linolenic acid (ALA) is considered to be a cardioprotective nutrient; however, some epidemiological studies have suggested that dietary ALA intake increases the risk of prostate cancer. The main objective was to conduct a systematic review and meta-analysis of case-control and prospective studies investigating the association between dietary ALA intake and prostate cancer risk.

DESIGN

A systematic review and meta-analysis were conducted by searching MEDLINE and EMBASE for relevant prospective and case-control studies.

INCLUDED STUDIES

We included all prospective cohort, case-control, nested case-cohort and nested case-control studies that investigated the effect of dietary ALA intake on the incidence (or diagnosis) of prostate cancer and provided relative risk (RR), HR or OR estimates.

PRIMARY OUTCOME MEASURE

Data were pooled using the generic inverse variance method with a random effects model from studies that compared the highest ALA quantile with the lowest ALA quantile. Risk estimates were expressed as RR with 95% CIs. Heterogeneity was assessed by χ(2) and quantified by I(2).

RESULTS

Data from five prospective and seven case-control studies were pooled. The overall RR estimate showed ALA intake to be positively but non-significantly associated with prostate cancer risk (1.08 (0.90 to 1.29), p=0.40; I(2)=85%), but the interpretation was complicated by evidence of heterogeneity not explained by study design. A weak, non-significant protective effect of ALA intake on prostate cancer risk in the prospective studies became significant (0.91 (0.83 to 0.99), p=0.02) without evidence of heterogeneity (I(2)=8%, p=0.35) on removal of one study during sensitivity analyses.

CONCLUSIONS

This analysis failed to confirm an association between dietary ALA intake and prostate cancer risk. Larger and longer observational and interventional studies are needed to define the role of ALA and prostate cancer.

Association between prostate cancer and urinary calculi: a population-based study

BACKGROUND

Understanding the reasons underlying the emerging trend and the changing demographics of Asian prostate cancer (PC) has become an important field of study. This study set out to explore the possibility that urinary calculi (UC) and PC may share an association by conducting a case-control study on a population-based database in Taiwan.

METHODS

The cases of this study included 2,900 subjects ≥ 40 years-old who had received their first-time diagnosis of PC and 14,500 randomly selected controls without PC. Conditional logistic regressions were employed to explore the association between PC and having been previously diagnosed with UC.

RESULTS

We found that prior UC was found among 608 (21.0%) cases and 2,037 (14.1%) controls (p<0.001). Conditional logistic regression analysis revealed that compared to controls, the odds ratio (OR) of prior UC for cases was 1.63 (95% CI = 1.47-1.80). Furthermore, we found that cases were more likely to have been previously diagnosed with kidney calculus (OR = 1.71; 95% CI = 1.42-2.05), bladder calculus (OR = 2.06; 95% CI = 1.32-3.23), unspecified calculus (OR = 1.66; 95% CI = 1.37-2.00), and ≥2 locations of UC (OR = 1.73; 1.47-2.02) than controls. However, there was no significant relationship between PC and prior ureter calculus. We also found that of the patients with UC, there was no significant difference between PC and treatment method.

CONCLUSIONS

This investigation detected an association between PC and prior UC. These results highlight a potential target population for PC screening.

Semen quality of fertile Japanese men: a cross-sectional population-based study of 792 men

OBJECTIVES

To establish a base line for future studies on temporal trends, to describe potential geographical differences in semen quality and reference values for studies of men from the general population.

DESIGN

Cross-sectional study of fertile men from four areas in Japan. Inclusion criteria were: age 20-45 years at the time of invitation, and both the man and his mother had to be born in Japan. Additionally, the current pregnancy of the female partner had to be achieved by normal sexual relations without any fertility treatment.

SETTING

Four Japanese study centres at urban areas located in Sapporo, Osaka, Kanazawa and Fukuoka.

PARTICIPANTS

792 men, median age 31.4 years, included from 1999 to 2002.

OUTCOME MEASURES

Semen volume, sperm concentration, total sperm count, sperm motility and sperm morphology.

RESULTS

Semen volumes, percentages of motile spermatozoa and morphologically normal spermatozoa differed slightly between the four groups, whereas no differences in sperm concentrations or total sperm counts were found. In total, 1.2% of men had a sperm concentration below 5 million/ml, 2.1% below 10 million/ml, 3.5% below 15 million/ml and 16.3% below 40 million/ml. For morphology, 14.7% had less than 5% normal spermatozoa. Reproductive hormone levels varied significantly, however, only little from a biological point of view.

CONCLUSIONS

This is the first cross-sectional study on semen quality covering fertile men from the major regions of Japan. It showed that semen quality of fertile Japanese men is comparable to that of the best in European regions. The results may serve as reference values for studies of men from the general population.

Do evolutionary life-history trade-offs influence prostate cancer risk? a review of population variation in testosterone levels and prostate cancer disparities

An accumulation of evidence suggests that increased exposure to androgens is associated with prostate cancer risk. The unrestricted energy budget that is typical of Western diets represents a novel departure from the conditions in which men's steroid physiology evolved and is capable of supporting distinctly elevated testosterone levels. Although nutritional constraints likely underlie divergent patterns of testosterone secretion between Westernized and non-Western men, considerable variability exists in men's testosterone levels and prostate cancer rates within Westernized populations. Here, I use evolutionary life history theory as a framework to examine prostate cancer risk. Life history theory posits trade-offs between investment in early reproduction and long-term survival. One corollary of life history theory is the 'challenge hypothesis', which predicts that males augment testosterone levels in response to intrasexual competition occurring within reproductive contexts. Understanding men's evolved steroid physiology may contribute toward understanding susceptibility to prostate cancer. Among well-nourished populations of Westerners, men's testosterone levels already represent an outlier of cross-cultural variation. I hypothesize that Westernized men in aggressive social environments, characterized by intense male-male competition, will further augment testosterone production aggravating prostate cancer risk.

Male contraception

Contraception is an accepted route for the control of population explosion in the world. Traditionally hormonal contraceptive methods have focused on women. Male contraception by means of hormonal and non hormonal methods is an attractive alternative. Hormonal methods of contraception using testosterone have shown good results. Non hormonal reversible methods of male contraception like reversible inhibition of sperm under guidanceare very promising. In this article we have reviewed the current available options for male contraception.

Total testosterone in young men is more closely associated than free testosterone with prostate cancer disparities

INTRODUCTION

Early adulthood has been suggested as the most relevant time to determine the influence of testosterone on prostate carcinogenesis. For a more detailed assessment of this hypothesis, the present study examined whether serum total or free testosterone in young men was more closely associated with prostate cancer disparities.

METHODS

A literature search was conducted for studies that reported both total and free testosterone levels for population samples of young men, along with prostate cancer incidences for the populations from which study populations were sampled. A previously developed analytical method was used to standardize the hormone levels of 19 population samples gathered from nine studies, and these standardized values were compared with disparities in prostate cancer incidence.

RESULTS

Population differences in total testosterone levels were significantly associated with prostate cancer disparities, r = 0.833, p = 0.001, as were population differences in free testosterone, r = 0.661, p = 0.027. After controlling for age differences, total and free testosterone remained associated with prostate cancer disparities, partial r = 0.888, p < 0.001, and partial r = 0.657, p = 0.039, respectively. A marginally significant difference existed in the strength of relationships between total and free testosterone with respect to prostate cancer disparities, with total testosterone exhibiting a stronger association, T(2) = 1.573, p = 0.077.

CONCLUSIONS

Across analyses, total testosterone demonstrated a more robust relationship than free testosterone with cancer disparities, which may suggest that total testosterone is the more sensitive biomarker for evaluating androgenic stimulation of the prostate gland.

Does ethnicity matter in male hormonal contraceptive efficacy?

The development of male hormonal contraception has progressed significantly during the last three decades. The ultimate goal is to produce an effective, safe and reversible male method of contraception that are within reach of and can be used by all men globally. This review aims to outline the recent developments in male hormonal contraception with special emphasis on how ethnicity influences acceptability, extent of sperm suppression, and rate of recovery of spermatogenesis. Baseline differences in testicular histomorphology and testosterone metabolism between East Asian and Caucasian men have been reported, but whether this contributes significantly to varying degrees of sperm suppression in response to exogenous testosterone therapy is less known. Testosterone alone male hormonal contraceptive regimens are effective and applicable for East Asian men, and less so for Caucasians. Combinations of progestins with androgens are sufficient to optimize effectiveness of suppression and applicability to all ethnicities. New compounds such as steroidal or non-steroidal selective androgen receptor modulators with dual androgenic and progestational activities are potential compounds for further development as male hormonal contraceptive methods. At the present time, combined androgen and progestin contraceptive regimens appear to be effective, safe, reversible and convenient to use for all men with ethnic, cultural and environmental differences. Further refinements on the hormonal agent, methods of delivery, and dose optimization of the androgen relative to the progestin are necessary. This goal mandates further investment and large clinical trials in multiethnic populations to better define safety and efficacy.

Hormonal approaches to male contraception

PURPOSE OF REVIEW

Condoms and vasectomy are male-controlled family planning methods but suffer from limitations in compliance (condoms) and limited reversibility (vasectomy); thus many couples desire other options. Hormonal male contraceptive methods have undergone extensive clinical trials in healthy men and shown to be efficacious, reversible and appear to be well tolerated.

RECENT FINDINGS

The success rate of male hormonal contraception using injectable testosterone alone is high and comparable to methods for women. Addition of progestins to androgens improved the rate of suppression of spermatogenesis. Supported by government or nongovernment organizations, current studies aim to find the best combination of testosterone and progestins for effective spermatogenesis suppression and to explore other delivery methods for these hormones. Translation of these advances to widespread use in the developed world will need the manufacturing and marketing skills of the pharmaceutical industry. Availability of male contraceptives to the developing world may require commitments of governmental and nongovernmental agencies. In a time when imbalance of basic resources and population needs are obvious, this may prove to be a very wise investment.

SUMMARY

Male hormonal contraception is efficacious, reversible and well tolerated for the target population of younger men in stable relationships. Suppression of spermatogenesis is achieved with a combination of an androgen and a progestin. Partnership with industry will accelerate the marketing of a male hormonal contraceptive. Research is ongoing on selective androgen and progesterone receptor modulators that suppress spermatogenesis, minimize potential adverse events while retaining the androgenic and gonadotropin suppressive actions.

Evidence for geographical and racial variation in serum sex steroid levels in older men

BACKGROUND

Despite considerable racial and geographical differences in human phenotypes and in the incidence of diseases that may be associated with sex steroid action, there are few data concerning variation in sex steroid levels among populations. We designed an international study to determine the degree to which geography and race influence sex steroid levels in older men.

METHODS

Using mass spectrometry, concentrations of serum androgens, estrogens, and sex steroid precursors/metabolites were measured in 5003 older men from five countries. SHBG levels were assessed using radioimmunoassay.

RESULTS

There was substantial geographical variation in the levels of sex steroids, precursors, and metabolites, as well as SHBG. For instance, Asian men in Hong Kong and Japan, but not in the United States, had levels of total testosterone approximately 20% higher than in other groups. Even greater variation was present in levels of estradiol, SHBG, and dihydrotestosterone. Group differences in body mass index did not explain most geographical differences. In addition, body mass index-independent racial differences were present; Black men had higher levels of estrogens (estradiol, estrone), and Asian men had lower levels of glucuronidated androgen metabolites.

CONCLUSIONS

On a global scale, there are important geographical and racial differences in the concentrations of serum sex steroids and SHBG in older men.

ACE inhibitor use was associated with lower serum dehydroepiandrosterone concentrations in older men

CONTEXT

Angiotensin converting enzyme (ACE) activity may influence the production of adrenal androgen precursors and testosterone. Use of ACE inhibitors may therefore have an influence on serum sex hormone concentrations in older men.

DESIGN AND METHODS

1486 out of 2,000 community-dwelling Chinese men aged 65years who participated in a cohort study were randomly selected to have archived fasting morning serum analyzed for androgen precursors and sex hormones. DNA was extracted from whole blood and analyzed for ACE gene I/D polymorphism.

RESULTS

Subjects with the ACE gene D allele (higher ACE activity) had higher serum dehydroepiandrosterone (DHEA) sulphate and DHEA than those with I/I genotype (P=0.014 and 0.018 respectively, Mann Whitney test). These differences were not significant after Bonferroni correction. Among those with history of hypertension, but without diabetes mellitus or cardiac failure, users of ACE inhibitors had significantly lower serum DHEA (median 1.78 versus 1.49ng/ml in non-users, P=0.0074, Mann Whitney test) and also tended to have lower serum androstenedione and androst-5-ene-3beta,17beta-diol (0.68 versus 0.72ng/ml in non-users; 552.4 versus 624.1pg/ml respectively, both P values <0.05). Serum testosterone and estradiol were not significantly changed.

CONCLUSIONS

ACE inhibitor use was associated with lower serum DHEA in older men.

Semen quality of Asian men

After the controversial report by Carlsen et al. in 1992 showing a possible decline in human semen quality over the past 50 years, many laboratories investigated their own records of semen findings that had been kept for the past decades, and a significant decrease in sperm quality was reported from some laboratories, but not others. At the beginning of the 21st century, a definitive interpretation of this issue has not yet been offered; however, it seems plausible that there are large regional differences in semen quality. Decreases in semen quality have been reported from various regions around the world, and a concurrent rise in the incidence of other reproductive problems, such as testicular cancer and genital abnormalities, has been observed in many regions. However, most of the reports showing regional differences were from Western or Western-derived countries, despite the fact that Asia is the region with the highest population on earth. Recently we undertook a cross-sectional study on fertile men in Japan to describe the current status of semen quality of Japanese men. We took confounders into consideration to allow a comparison with a previous European study. Japanese fertile men proved to have a semen quality at the level of Danish men, who were reported to have the lowest level among the men examined in the European study. This low level of sperm concentration in fertile Japanese men may result from differences in lifestyle or other environmental factors, but we cannot rule out the possibility of ethnic differences caused by different genetic variation or combination. To address this issue we need more information on the reproductive function in Asian men, who have been reported to have certain differences in reproductive characteristics from Caucasian men. This article is an attempt to review our present knowledge concerning the current status of semen quality in healthy Asian men on the basis of the limited publications from Asia. (Reprod Med Biol 2007; 6: 185-193).

Genetic polymorphisms of glutathione S-transferase T1 (GSTT1) and alterations of sex hormones in filling-station workers

OBJECTIVE

To determine the health effects of gasoline exposure as measured by levels of sex hormones (total testosterone, follicle-stimulating hormone [FSH], and luteinizing hormone [LH]) of male filling-station workers.

DESIGN

Case-control study.

SETTING

Filling stations in Shiraz (Fars province, Iran).

PATIENT(S)

One hundred fourteen male gasoline workers and 112 age-matched (+/-5 years) and sex-matched controls with no occupational exposure to gasoline.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Serum levels of testosterone, FSH, and LH, and expression of the GSTT1 genotype.

RESULT(S)

All hormone measurements were in the normal range although subclinical changes were detected in some indexes. Men exposed to petrochemicals had lower mean serum testosterone levels compared with unexposed men, regardless of the presence of the GSTT1 genotype. However, this decrease (expressed as mean +/- standard deviation) is most pronounced in the group possessing the GSTT1-null genotype (4.26 +/- 1.44 ng/mL vs. 5.48 +/- 0.98 ng/mL) compared with the group possessing the GSTT1 genotype (4.23 +/- 1.73 ng/mL vs. 4.67 +/- 1.21 ng/mL). The LH levels varied between the two groups; the mean serum LH was lower in the exposed versus unexposed men who possessed the GSTT1 genotype (2.82 +/- 1.32 IU/L vs. 3.20 +/- 1.17 IU/L) and higher in the exposed versus unexposed men who possessed the GSTT1-null genotype (3.52 +/- 1.37 IU/L vs. 2.76 +/- 1.07 IU/L).

CONCLUSION(S)

Testosterone levels were statistically significantly decreased in male gasoline workers compared with men who had had no occupational exposure to gasoline. The relevance of the GSTT1 genotype to these differences remains to be determined.