Paraoxonase polymorphism and its effect on male reproductive outcomes among Chinese pesticide factory workers.
Padungtod-C; Niu-T; Wang-Z; Savitz-DA; Christiani-DC; Ryan-LM; Xu-X
Am J Ind Med 1999 Sep; 36(3):379-387
Background: Serum paraoxonase has been associated with the metabolism of organophosphate pesticides in humans. Molecular analysis of the human paraoxonase gene (PON1) has revealed that Arg192 homozygotes have a greater detoxifying capability than Gln192 homozygotes. We examined the effects of PON1 genotypes on male reproductive outcomes and its interaction with exposure to organophosphate pesticides. MethodsWe studied 60 Chinese pesticide-factory workers and 89 textile-factory workers who were unexposed to pesticides. The respective allele frequencies of Arg192 and Gln192 were 0.62 and 0.38. Pesticide exposure among 36 exposed subjects and 12 unexposed subjects, regardless of gender, was assessed by personal measurement of pesticide residues over an entire 8-hr shift and measurement of urinary p-nitrophenol level over a 24-hr period. We analyzed semen and hormone data collected from male subjects. Results When the three PON1 genotypes were analyzed separately, a gene dose effect was not detected. We used the unexposed Arg192 homo/heterozygotes as the reference group, and re-analyzed the data. Exposed Arg192 homo/heterozygotes had signi®cantly lower sperm count (w2.9.01, P<0.01) and lower percentage of sperm with normal morphology (w2.4.18, P<0.05) than the reference group. Both unexposed Gln192 homozygotes (w2.4.90, P<0.05) and exposed Arg192 homo/heterozygotes (w2.10.00, P<0.01) showed signi®cantly lower sperm concentrations than the reference group. In addition, exposed Arg192 homo/heterozygotes had signi®cantly higher serum LH levels (w2.7.94, P<0.01) than the reference group. Conclusions Because of a small sample size, our ®ndings are highly preliminary. Nevertheless, it calls for further investigation of the interaction between the PON1 genotype and organophosphate pesticide exposure on male reproductive outcomes.
Organo-phosphorus-compounds; Organo-phosphorus-pesticides; Men; Reproductive-system-disorders; Hormone-activity; Hormones; Genes; Pesticides
Xiping Xu,MD, PhD, Harvard School of Public Health, Department of Environmental Health, 665 Huntington Avenue, FXB-101, Boston, MA 02115
American Journal of Industrial Medicine
Harvard University, Boston, Massachusetts