Lifestyle and demographic factors associated with human semen quality and sperm function

In this study, we sought to investigate the effect of lifestyle and demographic factors on classic and functional semen parameters. Three hundred and twenty-eight subjects who underwent semen analysis were recruited. Routine SA, sperm vitality, acrosome reaction (AR) assay and sperm DNA fragmentation index (DFI) were analyzed. Demographic and lifestyle information, including (1) BMI, (2) current smoking and alcohol drinking frequency, (3) sleep habits, (4) daily fluid intake, (5) weekly meat intake, (6) sports frequency, (7) trouser cell phone use, (8) age, and (9) abstinence time, were collected. Generalized additive models were used to analyze the possible non-linear association. The results showed that total sperm count (TSC) was significantly associated with age (P = 0.001), abstinence time (P = 0.001) and daily coffee intake (P = 0.044). Semen volume was significantly associated with age (P < 0.001) and daily coffee intake (P < 0.001). Sperm concentration was significantly associated with abstinence time (P = 0.011) and average sleep duration (P = 0.010). Sperm motility was significantly associated with age (P = 0.002) and daily juice intake (P = 0.001). Total motile sperm count was significantly associated with age (P = 0.003) and abstinence time (P = 0.009). DFI was significantly associated with age (P = 0.002), irregular sleeping habit (P = 0.008) and abstinence time (P = 0.032). The percentage of AR sperm was significantly associated with daily juice intake (P = 0.013). In conclusion, DFI and TSC were the most sensitive semen parameters for demographic and lifestyle features, whereas age had more influence on semen parameters than other demographic and lifestyle features. Abbreviations: BMI: body mass index; SA: semen analysis; AR: acrosome reaction; DFI: DNA fragmentation index; GAM: generalized additive model; TSC: total sperm count; TMC: total motile sperm count; IUI: intrauterine insemination; SCSA: sperm chromatin structure assay; SD: standard deviation; IQR: interquartile range; CBAVD: congenital bilateral absence of vas deferens; NEQAS: national external quality assessment service; HTF: human tubal fluid; HSA: human serum albumin.

本研究旨在探究生活方式与人口统计学因素对经典精液参数及功能性精液参数的影响。本研究共招募328名接受精液分析的受试者，对其常规精液分析（semen analysis, SA）、精子活力、顶体反应（acrosome reaction, AR）检测及精子DNA碎片指数（DNA fragmentation index, DFI）进行了分析。收集的人口统计学及生活方式信息包括：(1) 体质量指数（body mass index, BMI）；(2) 当前吸烟与饮酒频率；(3) 睡眠习惯；(4) 每日液体摄入量；(5) 每周肉类摄入量；(6) 运动频率；(7) 裤袋手机使用情况；(8) 年龄；(9) 禁欲时长。本研究采用广义加性模型（generalized additive model, GAM）分析变量间潜在的非线性关联。结果显示，总精子数（total sperm count, TSC）与年龄（P=0.001）、禁欲时长（P=0.001）及每日咖啡摄入量（P=0.044）存在显著关联；精液量与年龄（P<0.001）及每日咖啡摄入量（P<0.001）存在显著关联；精子浓度与禁欲时长（P=0.011）及平均睡眠时长（P=0.010）存在显著关联；精子活力与年龄（P=0.002）及每日果汁摄入量（P=0.001）存在显著关联；总活动精子数（total motile sperm count, TMC）与年龄（P=0.003）及禁欲时长（P=0.009）存在显著关联；DFI与年龄（P=0.002）、睡眠不规律（P=0.008）及禁欲时长（P=0.032）存在显著关联；顶体反应阳性精子百分比与每日果汁摄入量（P=0.013）存在显著关联。综上，DFI与TSC是对人口统计学及生活方式特征最为敏感的精液参数，而年龄对精液参数的影响程度高于其他人口统计学及生活方式因素。缩写说明：BMI：体质量指数（body mass index）；SA：精液分析（semen analysis）；AR：顶体反应（acrosome reaction）；DFI：DNA碎片指数（DNA fragmentation index）；GAM：广义加性模型（generalized additive model）；TSC：总精子数（total sperm count）；TMC：总活动精子数（total motile sperm count）；IUI：宫腔内人工授精（intrauterine insemination）；SCSA：精子染色质结构分析（sperm chromatin structure assay）；SD：标准差（standard deviation）；IQR：四分位数间距（interquartile range）；CBAVD：先天性双侧输精管缺如（congenital bilateral absence of vas deferens）；NEQAS：国家外部质量评估服务（national external quality assessment service）；HTF：人输卵管液（human tubal fluid）；HSA：人血清白蛋白（human serum albumin）。