Heavy metals, biomarkers of oxidative stress and changes in sperm function: A case-control study|
Nsonwu-Anyanwu, Augusta Chinyere; Ekong, Eworo Raymond; Offor, Sunday Jeremiah; Awusha, Ogar Francis; Orji, Oliver Chukwuma; Umoh, Ediang Idiongo; Owhorji, Jennifer Aleruchim; Emetonjor, Faith Rowland & Usoro, Chinyere Adanna Opara
Background: Heavy metal-induced oxidative stress has been implicated in abnormal
sperm functions and male infertility.
Objective: Serum and seminal levels of heavy metals and biomarkers of oxidative
stress were compared in fertile and infertile men.
Materials and Methods: A total of 130 men aged 20–60 yr comprising 30 azoospermic,
50 oligozoospermic, and 50 normozoospermic men were studied. Semen analysis
was done by world health organization guidelines, biomarkers of oxidative stress (total
antioxidant capacity (TAC), total plasma peroxidase (TPP), oxidative stress index (OSI),
vitamin C (vit C) and nitric oxide (NO)) and fructose by colorimetry and serum and
seminal heavy metals (zinc (Zn), selenium (Se), cadmium (Cd) and lead (Pb)) by atomic
Results: Azoospermic and oligozoospermic men had higher serum and seminal
peroxides (TPP, p = 0.00), higher serum heavy metals (Zn, Se, Pb, and Cd (p = 0.01))
and lower sperm concentration, %motility, serum and seminal antioxidants (vit C, TAC,
NO, GSH (p = 0.01)) compared to normozoospermic men. Higher seminal peroxides
(TPP, p = 0.001), heavy metals (Pb and Cd (p = 0.03)) and lower sperm concentration,
%motility, and seminal antioxidants (TAC and NO (p = 0.00)) were also observed
in azoospermic men compared to oligozoospermic men. Negative correlations were
observed between seminal fructose and seminal vit C (r = -0.535, p = 0.015), GSH (r =
-0.734, p = 0.000), NO (r = -0.714, p = 0.000), Zn (r = -0.774, p = 0.000) and Se (r = -0.719,
p = 0.000) only in azoospermic men.
Conclusion: Elevated heavy metal levels, increased lipid peroxidation and antioxidant
depletion is associated with abnormal sperm functions in men studied.
Heavy metals; Antioxidants; Lipid peroxidation; Oxidative stress; Sperm function.