University of South Dakota Sanford School of Medicine, Sioux Falls, South Dakota.
S D Med. 2022 Oct;75(10):448.
Intracytoplasmic sperm injection (ICSI) has revolutionized the treatment of couples with male factor infertility but results remain suboptimal, suggesting the need for further investigation into the molecular biology of spermatozoa. Limitations to traditional semen analysis have brought new methods to the forefront like Sperm Chromatin Structure Assay (SCSA), which uses flow cytometry to measure sperm DNA fragmentation. Increased DNA damage in semen has been correlated with failed IVF cycles and decreased fertilization. Hypovitaminosis D has been associated with abnormal testicular function, including elevated sperm DNA fragmentation in a murine model. The objective of this study was to elucidate the possible corollary relationship between serum vitamin D levels and sperm DNA fragmentation in males seeking infertility treatment.
This study was conducted using a prospective cohort of consenting males seeking infertility treatment at a medium sized Midwest infertility clinic. Serum vitamin D levels and semen samples were collected from each patient. Sperm samples were analyzed by semen analysis according to World Health Organization current guidelines. The SCSA was used to measure acid-induced DNA fragmentation. The relationship between dichotomous variables: alcohol use, tobacco use and BMI were examined using a chi-square test of independence. The relationship between deficient, insufficient and sufficient Vitamin D levels and sperm parameters were analyzed using an analysis of variance.
Serum vitamin D levels were categorized as deficient (less than 20 ng/mL), insufficient (20-30 ng/mL), and sufficient (greater than 30 ng/mL). Of the 111 patients participating, 9 were excluded leaving 102 total patients. The patients were stratified by vitamin D levels: deficient (n=24), insufficient (n=43), and sufficient (n=35). No significant relationship was found between serum vitamin D levels and sperm DNA fragmentation in males seeking infertility treatment. A lack of alcohol consumption was correlated with increased high DNA stainability, a measure of nuclear immaturity (p=0.0042). There was a significant relationship between increased BMI and deficient/insufficient serum vitamin D levels (p=0.0012).
Serum vitamin D levels did not have a statistically significant impact on sperm DNA fragmentation. This study further solidifies the known associations between BMI and serum vitamin D levels. Limitations of the study included number of participants, insufficient power, and time constraints. Further examination of the correlation between seminal and serum vitamin D levels as well as the impact of alcohol on sperm DNA should be explored.
胞浆内单精子注射（ICSI）彻底改变了男性因素不育症患者的治疗方法，但结果仍不尽如人意，这表明需要进一步研究精子的分子生物学。传统精液分析的局限性带来了新的方法，如精子染色质结构分析（SCSA），它使用流式细胞术来测量精子 DNA 碎片化。精液中 DNA 损伤的增加与体外受精（IVF）周期失败和受精减少有关。维生素 D 缺乏症与睾丸功能异常有关，包括在鼠模型中精子 DNA 碎片化增加。本研究旨在阐明血清维生素 D 水平与寻求不孕治疗的男性精子 DNA 碎片化之间可能存在的相关性。
本研究采用前瞻性队列研究，纳入在中西部一家中型不孕诊所寻求不孕治疗的同意男性。从每位患者采集血清维生素 D 水平和精液样本。根据世界卫生组织（WHO）现行指南，对精液样本进行精液分析。使用精子染色质结构分析（SCSA）来测量酸诱导的 DNA 碎片化。使用独立性卡方检验检查二项变量（饮酒、吸烟和 BMI）之间的关系。使用方差分析分析维生素 D 水平不足、不足和充足与精子参数之间的关系。
血清维生素 D 水平分为不足（<20ng/ml）、不足（20-30ng/ml）和充足（>30ng/ml）。在 111 名参与的患者中，有 9 名被排除在外，共 102 名患者。根据维生素 D 水平对患者进行分层：不足（n=24）、不足（n=43）和充足（n=35）。在寻求不孕治疗的男性中，血清维生素 D 水平与精子 DNA 碎片化之间未发现显著关系。缺乏饮酒与高 DNA 染色性增加有关，高 DNA 染色性是核不成熟的一个指标（p=0.0042）。BMI 增加与血清维生素 D 水平不足/不足之间存在显著关系（p=0.0012）。
血清维生素 D 水平对精子 DNA 碎片化没有统计学显著影响。本研究进一步证实了 BMI 和血清维生素 D 水平之间已知的相关性。研究的局限性包括参与者数量、效力不足和时间限制。应进一步研究精液和血清维生素 D 水平之间的相关性以及酒精对精子 DNA 的影响。
