Alteration of serum sex hormonal profile in male gasoline filling station workers in respect to their polymorphism of glutathione S-transferase M1

Alterations in offspring sex ratio at birth and level of serum testosterone in filling-station workers have been reported. To determine the association of glutathione S-transferase M1 (GSTM1) polymorphism with serum levels of total testosterone, follicle-stimulating hormone (FSH), and luteinizing hormone (LH) of male filling-station workers, the present study was carried out on 114 gasoline workers and 100 age- and sex-matched controls with no occupational exposure to gasoline. We have found no significant difference between the workers and controls for levels of sex hormones in the presence of active GSTM1 genotype. Among subjects with the GSTM1 null genotype, there was significant difference between exposed and unexposed subjects for the concentration of testosterone (t = 4.37, df = 97, P < 0.001). To investigate whether one null genotype could be compensated by an active genotype for the other isoenzyme, the mean concentrations of sex hormones was compared between the exposed and control groups with respect to their combinations of the GSTM1 and GSTT1 genotypes. The exposed group having either “null GSTM1/positive GSTT1” (t = 2.76, df = 72, P = 0.007) or “null GSTM1/null GSTT1” (t = 4.91, df = 23, P < 0.001) combinations had a lower testosterone compared with the controls. It seems that GSTM1 polymorphism has more effect on serum testosterone compared to the GSTT1 polymorphism, in exposed workers.

► Effect of GSTM1 polymorphism on testosterone level in filling workers was investigated.
► GSTM1 polymorphism associated with testosterone level in filling station workers.
► GSTM1 genotypes have more effect on serum testosterone compared to the GSTT1 genotypes.