Phthalate exposure with sperm quality among healthy Chinese male adults: The role of sperm cellular function

Adverse male reproduction caused by phthalate ester (PAE) exposure has been well documented in vivo. How-ever, existing evidence from population studies remains inadequate to demonstrate the impact of PAE exposure on spermatogenesis and underlying mechanisms. Our present study aimed to explore the potential link between PAE exposure and sperm quality and the possible mediation by sperm mitochondrial and telomere in healthy male adults recruited from the Hubei Province Human Sperm Bank, China. Nine PAEs were determined in one pooled urine sample prepared from multiple collections during the spermatogenesis period from the same participant. Sperm telomere length (TL) and mitochondrial DNA copy number (mtDNAcn) were determined in sperm samples. The sperm concentration and count per quartile increment in mixture concentrations were-4.10 million/mL (-7.12,-1.08) and-13.52% (-21.62%,-4.59%), respectively. We found one quartile increase in PAE mixture concentrations to be marginally associated with sperm mtDNAcn (& beta; = 0.09, 95% CI:-0.01, 0.19). Mediation analysis showed that sperm mtDNAcn significantly explained 24.6% and 32.5% of the relationships of mono-2-ethylhexyl phthalate (MEHP) with sperm concentration and sperm count (& beta; =-0.44 million/mL, 95% CI:-0.82,-0.08; & beta; =-1.35, 95% CI:-2.54,-0.26, respectively). Our study provided a novel insight into the mixed effect of PAEs on adverse semen quality and the potential mediation role of sperm mtDNAcn.

Automated summary

This study examined the potential link between phthalate ester (PAE) exposure and sperm quality in healthy male adults from Hubei Province, China. The results showed that PAE exposure was associated with decreased sperm concentration and count, and this effect may be mediated by changes in sperm mitochondrial DNA copy number.