Analysis of semen quality, sperm DNA fragmentation and heavy metals in urine in 1202 males of premarital medical examination

Background: Studies have shown that trace elements may adversely affect male reproduction, even at low levels. The toxic effects of heavy metals on the reproductive system have been mainly studied in animal experiments, and epidemiological evidence for populations exposed to the general environment is limited and inconsistent. Objectives: Our aim in this study was to analyze the relationship between semen quality and multiple metals or metalloids (Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, Pb, As and Se) in men undergoing premarital medical examinations (PME) and living in the same city. Methods: Among 1202 PME men, semen quality and sperm DNA integrity were measured by using flow cytometry. Urine heavy metals were tested using a mass spectrometer at our infertility clinic. The urinary levels of various metals and the sperm DNA fragmentation rate of men with normal sperm parameters (NSP) and abnormal sperm parameters (ASP) were compared. Results: Among1202 males, 42.0% (505/1202) were smokers, and 42.9% (516/1202) were alcohol users. A total of 594 men (594/1202, 49.4%) had NSP such as sperm concentration, total sperm, sperm motility and sperm morphology, whereas 608 men (608/1202, 50.6%) had some type of sperm-pathology (ASP); 600 had oligo- or astheno- or terato- or oligoasthenoteratozoospermia (OAT), 8 azoospermia 8/1202, 0.7%). The males of long-term outdoor work, smoking and drinking alcohol in ASP group were 252 (41.4%) , 308 (50.7%) and 283 (46.5%), respectively, and more than NSP group [(180, 30.3%), (33.1%) and (39.2%)] (P