精子DNA碎片指数与精液参数的相关性分析

Correlation of sperm DNA fragmentation index with semen parameters

目的:探讨精子DNA碎片指数(DFI)与精液参数的关系,并评价其在男性精子质量评估中的应用价值。方法:收集9 694例男性精液标本,采用流式细胞仪辅助的精子染色质结构分析法(SCSA)进行精子DFI和高DNA着色性(HDS)检测,根据WHO《人类精液检查与处理实验室手册》(第5版)精液参数参考值标准分为正常组和异常组,异常组再依据精子浓度、精子总活率和前向运动精子百分率异常程度分为A组:精子浓度(11.3～14.0)×10~6/ml,精子总活率30%～39%,前向运动精子百分率24%～31%;B组:精子浓度(7.5～11.2)×10~6/ml,精子总活率20%～29%,前向运动精子百分率16%～23%;C组:精子浓度(3.8～7.4)×10~6/ml,精子总活率10%～19%,前向运动精子百分率8%～15%;D组:精子浓度(0～3.7)×10~6/ml,精子总活率0～9%,前向运动精子百分率0～7%;按照不同DFI值分为<15%、15%～30%和>30%3组。分析DFI与精液参数的关系。结果:正常组DFI均显著低于异常组及其亚组(P均<0.01);各异常亚组(A、B、C、D组)随着精子指标的降低DFI逐渐升高(P<0.01)。根据DFI分组,发现DFI与年龄、禁欲时间、精液体积、精液pH、精子浓度、精子总活率、前向运动精子百分率、正常形态精子百分率以及HDS的差异均有统计学意义(P均<0.01);相关性分析表明DFI与年龄、禁欲时间、精液体积和HDS存在正相关(r分别为0.15、0.10、0.05、0.15,P均<0.01),而与精液pH、精子浓度、精子总活率、前向运动精子百分率和正常形态精子百分率存在负相关(r分别为-0.06、-0.27、-0.53、-0.52、-0.16,P均<0.01)。多重线性回归分析表明精子总活率、精子浓度、年龄、禁欲时间和精液pH是与DFI相关的5个重要相关变量,标准化回归系数分别为-0.47、-0.19、0.12、0.07、-0.04,P均<0.01。结论:DFI与精液参数存在中等相关性,二者可协同评估男性精子质量。

Objective: To explore the relationship of sperm DNA fragmenation index(DFI) with semen parameters and assess its application value in the evaluation of semen quality. Methods: A total of 9 694 semen samples were collected and examined for sperm DFI and high DNA stainability(HDS) by flow cytometry-assisted sperm chromatin structure analysis(SCSA). According to the WHO Laboratory Manual for the Examination and Processing of Human Semen(5 th Ed), the samples were divided into a normal group and abnormal groups A(sperm concentration [SC]: [11.3-14.0] ×10~6/ml, total sperm motility [TSM]: 30%-39%, progressively motile sperm [PMS]: 24%-31%), B(SC: [7.5-11.2] ×10~6/ml, TSM: 20%-29%, PMS: 16%-23%), C(SC: [3.8-7.4] ×10~6/ml, TSM: 10%-,19% PMS: 8%-15%) and D(SC: [0-3.7]×10~6/ml, TSM: 0-9%, PMS: 0-7%), and also into three sperm DFI groups(DFI <15%, 15%-30% and >30%). The correlation between sperm DFI and seminal parameters was analyzed by Pearson correlation and multiple linear regression analyses. Results: DFI was dramatically lower in the normal than in the abnormal groups(P < 0.01), and increased in proportion to the decrease of semen parameters in the abnormal groups A, B, C and D(P < 0.01). Pearson correlation analysis showed that DFI was correlated positively with age(r = 0.15, P < 0.01), abstinence time(r = 0.10, P < 0.01), semen volume(r = 0.05, P < 0.01) and HDS(r = 0.15, P < 0.01), but negatively with semen pH(r =-0.06, P < 0.01), SC(r =-0.27, P < 0.01), TSM(r =-0.53, P < 0.01), PMS(r =-0.52, P < 0.01) and morphologically normal sperm(r =-0.16, P < 0.01). Multiple linear regression analysis revealed that TSM, SC, age, abstinence time and semen pH were five important variables associated with DFI, with standardized regression coefficients of-0.47,-0.19, 0.12, 0.07, and-0.04, respectively(all P < 0.01). Conclusion: There is a moderate correlation between sperm DFI and semen parameters, which can be used synergistically for the assessment of semen quality.