Monthly variation in human semen quality in male partners of infertile women in the tropics

Chia, Sin Eng; Lim, Soon-Tiong Alvin; Ho, Lee‐Mee; Tay, Sun Kuie

doi:10.1093/humrep/16.2.277

Cited by 22 publications

(15 citation statements)

References 12 publications

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“…This discrepancy should be considered when comparing data of semen volumes between different laboratories. According to our comparison of the results from different Asian studies, the mean semen volumes of China (north/south/central), Thailand, Singapore and India were 3.0/2.9/2.4, 2.5, 2.4 and 2.5 mL, respectively 35 . In contrast, semen volume of the fertile Japanese men was 3.2 mL; 20 which is the highest value among the Asian men examined here.…”

Section: Review Of Reproductive Parameters In Asian Healthy Menmentioning

confidence: 57%

Semen quality of Asian men

Iwamoto

Nozawa

Yoshiike

2007

Reprod Medicine & Biology

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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 Westernderived 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)

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Section: Review Of Reproductive Parameters In Asian Healthy Menmentioning

confidence: 57%

Semen quality of Asian men

Iwamoto

Nozawa

Yoshiike

2007

Reprod Medicine & Biology

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“…Although air conditions have improved recently, air quality is reportedly worse, and the PAH levels are higher in December in this city (CEPB 2007). Additionally, several reports have indicated that sperm quality is subject to seasonal changes because of temperature changes, the length of daylight, or ejaculatory frequency (Carlsen et al 2004; Chia et al 2001; Hansen et al 2010). The winter season in Chongqing sees mild weather with overcast conditions and average temperatures around 10°C.…”

Section: Discussionmentioning

confidence: 99%

Association between Urinary Polycyclic Aromatic Hydrocarbon Metabolites and Sperm DNA Damage: A Population Study in Chongqing, China

Han

Zhou²,

Cui³

et al. 2011

Environ Health Perspect

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BackgroundPolycyclic aromatic hydrocarbons (PAHs), a class of the most ubiquitous environmental contaminants, may reduce male reproductive functions, but the data from human population studies are very limited.ObjectivesWe designed this study to determine whether environmental exposure to PAHs contributes to the alteration in semen quality, sperm DNA damage, and apoptosis in the general male human population.MethodsWe measured urinary levels of four PAH metabolites and assessed semen quality, sperm apoptotic markers with Annexin V assay, and sperm DNA damage with comet assay in 232 men from Chongqing, China.ResultsWe found that increased urinary 2-hydroxynaphthalene (2-OHNa) levels were associated with increased comet parameters, including the percentage of DNA in the tail (tail%) [β coefficient = 13.26% per log unit 2-OHNa (micrograms per gram creatinine); 95% confidence interval (CI), 7.97–18.55]; tail length (12.25; 95% CI, 0.01–24.52), and tail distribution (7.55; 95% CI, 1.28–18.83). The urinary level of 1-hydroxypyrene was associated only with increased tail% (5.32; 95% CI, 0.47–10.17). Additionally, the increased levels of four urinary PAH metabolites were significantly associated with decreased vital Annexin V negative sperm counts. However, there was no significant association between urinary PAH metabolite levels and human semen parameters or morphology of the sperm samples.ConclusionsOur data indicate that the environmental level of PAH exposure is associated with increased sperm DNA damage but not with semen quality. These findings suggest that exposure to PAHs may disrupt sperm DNA and thereby interfere with human male fertility.

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“…Chia et al reported there were no significant month-to-month fluctuations in semen volume and sperm density among men who resided in the tropics [26], where there are minimal changes in temperature, unlike the seasonal variation of climate in the New England region. In our study, improved semen parameters in the spring may reflect spermatogenesis during the cold New England winter.…”

Section: Discussionmentioning

confidence: 99%