| Objective: Most epidemiological studies have found the adverse effects of metal exposure on male reproductive health,and recent studies have shown that tobacco exposure may increase the adverse effects of heavy metals on male semen quality.In order to elucidate the effects of metal exposure and tobacco exposure on male semen quality,the contents of urine metals and Cotinine were used as exposure indicators,to study the effect of the interaction between metal and Cotinine on the male semen quality.Methods: From October 2017 to February 2018,men of child-bearing age who visited the Outpatient Department of Urology Department of a third-class Hospital in Wuhan,Hubei Province,were recruited in our study(N=394).Personal Information(basic demographics,personal habits,personal environmental exposure,past medical history and history of drug use),urine and semen samples were collected.The concentrations of cotinine and 23 kinds of metal(Al,Ti,V,Cr,Mn,Cu,Zn,As,Fe,Co,Ni,Se,Rb,Sr,Mo,Cd,Sn,Sb Ba,W,Tl,Pb,U)in urine were determined by gas chromatography-mass spectrometry(GC-MS)and Inductively coupled plasma mass spectrometry(ICP-MS)respectively.The semen quality parameters were measured by computer-assisted Semen Analysis System(CASA),and the study population was divided according to the manual of human sperm testing and Processing Laboratory(5th edition)drafted by WHO in 2010.Under the premise of correcting confounding factors,binary logistic regression and multiple linear regression models were used to study the independent effects of different metal concentrations and their interaction with cotinine on male semen quality.Results: In the analysis of correlation between urinary metals and semen quality,the risk of abnormal sperm motility increased with the higher Al and Mn concentration(P for trend 0.005,0.006).Compared with the first decile group,the risk of abnormal sperm motility in the fourth decile group increased by 2.539 times(95% CI: 1.066,4.365)and 2.744 times(95% CI: 1.270,5.928)respectively.With the increasing of Mn and Pb concerntration,the sperm survival rate(square root inverse sine transform)showed a decreasing trend(P for trend 0.007,0.048).Compared with the first decile group,the sperm survival rate in the fourth decile group(square root inverse sine transformation)decreased by 0.020%(95% CI: 0.130,-0.020)and 0.040%(95% CI:-0.100,0.007)respectively.In the correlation analysis of the interaction between metals and cotinine on semen quality,we see that the risk of abnormal sperm density increased(Pint for trend=0.020)with the higher level of interaction items of Cd and cotinine.Compared with the first level of the items,the risk of abnormal sperm density increased 5.132 times(95% CI: 1.198,21.991),4.318 times(95% CI: 1.060,17.593)respectively.The risk of abnormal sperm total count increased with the higher concentration of the interaction items of Al and cotinine(Pint for trend=0.020).Compared with the first level,the risk of abnormal sperm total count of the third and fourth levels increased 5.137 times(95% CI: 1.329,19.852)and 4.517 times(95% CI: 0.977,20.880)respectively.The risk of abnormal sperm motility increased with the higher concentration of the interaction items of Zn and cotinine(Pint for trend 0.048),compared with the first level,the risk of abnormal sperm motility of the fourth level increased 2.568 times(95% CI: 1.101,5.992).Conclusions: The correlation analysis showed that the higher concentrations of Al and Mn may increase the risk of abnormal sperm density.When the concentration of Pb and Mn increased,the sperm survival rate decreased.Analysis of the effect of interaction between the metals and cotinine on semen quality showed that tobacco exposure may aggravate the adverse effects of Al,Cd and Zn on male semen quality,however,the results of this analysis need to be further expanded sample size to confirm. |
