Relationship between Testosterone, Oxidative Stress Biomarkers and Antioxidant levels in Male Auto-mechanics in Ibadan, Nigeria

Abstract

Hypogonadism attributable to males with metabolic syndrome was observed in automechanics occupationally exposed to mixed 
chemicals accompanied by oxidative stress (OS). We evaluated association between testosterone, OS biomarkers, enzymatic and 
non-enzymatic antioxidants in normal weight automechanics in Ibadan. This was a prospective cross sectional study involving 
100 normal weight males aged 18 – 60 years. They were 50 automechanics in Ibadan, age and anthropometry matched with 50 
eugonadic males from University College Hospital and environs (controls). Demographic, anthropometry, social habits and 
dietary history were obtained by standard methods. Blood (10mL) was collected and serum/plasma was used for biochemical 
analyses. Enzymatic antioxidants (catalase, glutathione peroxidase, superoxide dismutase (SOD) and glutathione -S- transferase 
(GST); non-enzymatic antioxidants (reduced glutathione (GSH), selenium and zinc), OS biomarkers (hydrogen peroxide (H2O2), 
malondialdehyde (MDA), total antioxidant capacity (TAC), total plasma peroxides (TPP) and oxidative Stress index (OSI) were 
estimated spectrophotometrically. Testosterone was assayed by enzyme immunoassay method (Dialab, Austria). Student’s t-test, 
Chi-square test and multiple regression were used for comparisons, associations and relationships respectively, which were 
significant at P<0.05. Testosterone, TPP, OSI, GST, MDA, H2O2, selenium and zinc concentrations were significantly higher 
while catalase and SOD concentrations were lower in automechanics than controls (P<0.05). However, testosterone levels in 
both groups were within the normal reference interval. TAC, OSI and GSH had significantly negative relationship while TPP 
had positive relationship with years at occupation in automechanics only (P<0.05). Automechanics may have OS but not 
hypogonadism probably due to increased antioxidant intake.