Associations of Lifestyle Factors with Cadmium and Nickel in Seminal Fluid of Potential Sperm Donors

This study aimed to examine the associations between lifestyle factors and concentrations of cadmium (Cd) and nickel (Ni) in seminal fluid (SF) of potential sperm donors, and to determine whether these metals are related to donor qualification status. Between 2015 and 2021, 206 healthy men aged 18–40 were screened as potential sperm donors at reproductive centres in Moravia, Czech Republic. Respondents completed a lifestyle questionnaire covering diet, sedentary behaviour, physical activity, sleep, substance usage, and psychological well-being. Initial semen analysis determined their qualification as donors. Seminal Cd and Ni levels were measured by high-resolution continuum source electrothermal atomic absorption spectrometry (HR-CS ETAAS). Non-parametric methods were used for statistical evaluation. Elevated Cd concentrations were significantly associated with smoking (P = 0.008), fish (P = 0.024) and confectionery consumption, uninterrupted sedentary time (P = 0.017), lower psychological well-being (P = 0.024), and sleep duration. Higher fruit (P = 0.040) and vegetable (P = 0.015) intake resulted in increased seminal Ni concentrations, but without direct association to qualification status. Increased Cd levels were also associated with a bigger size of the settlement (P = 0.012). Notably, Cd levels were significantly increased among non-qualified donors (P = 0.002), while no such pattern was observed for Ni. No direct significant differences in lifestyle factors were shown between qualified and non-qualified donors. These findings highlight associations between lifestyle factors and seminal Cd levels in potential sperm donors, providing new insights into the role of trace elements in male reproductive health.