The Effect of Smoking on Serum and Seminal Plasma Zinc Levels in Infertile Men: A Comparative Study

Abstract

Background:    Male infertility is the inability to conceive due to low sperm count, poor sperm function, or blockages. Smoking has a negative effect on male infertility because it makes breathing and other physiological processes—including respiration—difficult. Chemicals in tobacco smoke, such as oxidants and pro-oxidants, increase oxidative stress in the body, leading to the production of free radicals. Zinc plays a crucial role in combating this oxidative damage, as it is a key component of several antioxidant enzymes like peroxidase, catalase, and superoxide dismutase. Disruptions in zinc metabolism, such as impaired enzyme utilization of zinc, may contribute to oxidative damage caused by smoking. This oxidative stress can negatively impact sperm health and function, highlighting zinc\'s important role in preserving male fertility.
Objective:    To assess the effect of smoking on zinc levels in the serum and seminal plasma of infertile males through a comparative analysis between smokers and non-smokers. 
Methods:    A case-control study recruited 60 infertile men, divided into two groups: 30 smokers and 30 non-smokers. Data on their demographics, hematological indices, and key biomarkers were collected, including serum and seminal plasma zinc levels, as well as serum levels of testosterone, follicle-stimulating hormone (FSH), and luteinizing hormone (LH). 
Results:    The zinc levels in both blood and seminal plasma were significantly lower in smokers compared to non-smokers (P <0.05). Specifically, the mean zinc concentration in the serum of smokers was 1.12 µg/dL, compared to 1.24 µg/dL in non-smokers, and in seminal plasma, it was 1.04 µg/mL for smokers versus 1.10 µg/mL for non-smokers.
Conclusion:    Smoking has negative impact of on zinc levels in the blood and seminal plasma of infertile men. Zinc is essential for reproductive health, playing a crucial role in sperm production and function. This emphasizes the urgent need for smoking cessation programs to protect reproductive health. 
Keywords:    Zinc, cigarette smoking, serum, seminal plasma, male fertility
Citation:    Hadi HE, Abd Ali ZA, Hamed SH, Ali RF. The effect of smoking on serum and seminal plasma zinc levels in infertile men: A comparative study. Iraqi JMS. 2025; 23(2): 312-316. doi: 10.22578/IJMS.23.2.14