| Summary: | 碩士 === 台北醫學院 === 醫學研究所 === 90 === Environmental factors have been suggested to play a role in human infertility. The prevalence of infertility has increased from 8 to 15% over the past 2 decades in industrialized countries, with heavy metals being implicated in male reproductive dysfunction. Lead (Pb) is an environmental pollutant shown to adversely affect male reproductive functions. Cadmium (Cd) has been reported to affect the reproductive systems of male animals. On the other side, Selenium (Se) is required for normal testicular development and spermatogenesis in rats. Studies have shown that heavy metals produce lipid peroxidation, and this phenomenon is associated with improper semen quality. Therefore, the aim of this work were: (1) to explore the basic features in male infertility; (2) to analyze and find out the relationship between metals concentration in blood and semen analysis in male infertility; (3) to explore the interaction of other risk factors with metals exposure and male infertility.
We divided sperm count of infertile men 296 in the latest four years into four groups: 0, 1~5, 6~19 and more then 20 million/ml. The average age (p=.001), concentrations of luteinizing hormone（LH）(p=.001) and follicle-stimulating hormone（FSH）(p=.000) of four groups were statistically significant differences. We also divided infertile men’s sperm motility into three groups: 0, 1~49 and more then 50%. The average age (p=.002), concentrations of LH (p=.002) and FSH (p=.022) of three groups were significant differences, too. In the multiple linear regression, the result showed that sperm motility was significantly associated with FSH (p=.019) and testis sizes (p=.037) adjusted by age.
A total of 41 infertile men’s bloods in a latest year were collected, and the clinical features of these patients are similar to before. The average concentration of blood lead, cadmium and selenium is 19.90 ± 3.98, 1.80 ± 0.88 and 97.87 ± 2.61 μg/L respectively. In the multiple regression, the result showed positive impact of sperm count with FSH (p=.014)and testosterone (p=.024), adjusted by age, blood lead, blood selenium, testis sides, malondialdehyde（MDA）, glutathione disulfide（GSH）and superoxide dismutase（SOD）. A negative relation of sperm count with blood lead and a positive relation with blood selenium, but both of them were non-significance. In other regression models, blood lead and blood cadmium level were negatively, and testosterone were positively related to sperm motility with statistical non-significance. A significance decrease of sperm motility was found by aging and testis atrophy, and marginal statistical significant protection effect were also found by blood selenium increasing. Subjects of non-infertility group and high exposure group should be collected for the further exploration.
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