Division of Preventive Medicine and Public Health, University of Murcia School of Medicine, Espinardo Murcia, Spain.
Andrology. 2013 May;1(3):408-13. doi: 10.1111/j.2047-2927.2012.00058.x. Epub 2013 Jan 11.
Several studies have investigated temporal trends in semen quality in Northern Europe, but none has examined this question in Southern Europe. A prior study conducted in Almeria Province (Southern Spain) reported higher sperm count and concentration among Spanish young men recruited from 2001 to 2002 compared with young men from Northern Europe. The aim of this new study was to examine whether semen quality has changed among Spanish young men in the last decade. In this cross-sectional study, questionnaires and semen samples were collected from 215 healthy young university students from Murcia Region between 2010 and 2011. The 273 men from the Almeria study previously studied were included in a trend analysis of the two populations from Southern Spain. Descriptive statistics were calculated for the Murcia study population and these and semen variables for the Murcia and Almeria study populations were compared. Study methods and population characteristics were similar across the two studies. Therefore, we used multiple linear regression analyses on the combined population (controlling for study centre, age, ejaculation abstinence time, season, smoking, medication during the last 3 months, Body mass index (BMI), presence of varicocoele and prenatal exposure to tobacco) to look for a birth-cohort effect over the combined study period (2001-2011). Sperm concentration and total sperm count declined significantly with year of birth in the pooled analysis (β = -0.04 and β = -0.06, respectively, both p < 0.01). Sperm counts were significantly lower in Murcia study subjects than in the Almeria participants; sperm concentration median (5th-95th) = 44.0 (8.9-129) million/mL vs. 51.0 (5.0-206) million/mL; p < 0.01 and total sperm count = 121 (17.8-400) million vs. 149 (8.0-599) million; p < 0.01. Other semen variables did not differ significantly between the two studies. Our study suggests that total sperm count and sperm concentration may have declined in young Spanish men over the last decade.
几项研究调查了北欧地区精液质量的时间趋势，但没有研究过南欧地区的这一问题。先前在阿尔梅里亚省（西班牙南部）进行的一项研究报告称，与来自北欧的年轻人相比，2001 年至 2002 年招募的西班牙年轻男性的精子数量和浓度更高。这项新研究的目的是研究过去十年中西班牙年轻男性的精液质量是否发生了变化。在这项横断面研究中，2010 年至 2011 年间，从穆尔西亚地区的 215 名健康年轻大学生中收集了问卷和精液样本。先前研究的阿尔梅里亚的 273 名男性被纳入了来自西班牙南部的两个人群的趋势分析。计算了穆尔西亚研究人群的描述性统计数据，并比较了穆尔西亚和阿尔梅里亚研究人群的这些和精液变量。两项研究的方法和人群特征相似。因此，我们在合并人群中使用多元线性回归分析（控制研究中心、年龄、射精禁欲时间、季节、吸烟、过去 3 个月内的药物治疗、体重指数 (BMI)、精索静脉曲张的存在和产前接触烟草）来寻找合并研究期间（2001-2011 年）的出生队列效应。在合并分析中，精子浓度和总精子计数随着出生年份的增加而显著下降（β=-0.04 和β=-0.06，均 p<0.01）。穆尔西亚研究对象的精子计数明显低于阿尔梅里亚参与者；精子浓度中位数（5 至 95 百分位）=44.0（8.9-129）百万/ml 与 51.0（5.0-206）百万/ml；p<0.01 和总精子计数=121（17.8-400）百万与 149（8.0-599）百万；p<0.01。两项研究之间其他精液变量无显著差异。我们的研究表明，在过去十年中，西班牙年轻男性的总精子计数和精子浓度可能有所下降。
