Association of occupational lead exposure with erythrocytic parameters and nitric oxide-related metabolites: a case-control study.

Background/aim: Occupational lead (Pb) exposure remains a significant public health concern due to its persistent presence in industrial environments and its cumulative toxic effects. Although the hematological and neurological consequences of Pb exposure are well documented, early vascular effects and the mechanisms associated with potential endothelial impairment remain unclear. This study aimed to investigate the associations between Pb exposure, erythrocytic parameters, and nitric oxide (NO)-related metabolites (asymmetric dimethylarginine [ADMA], symmetric dimethylarginine [SDMA], arginine, homoarginine, and citrulline) to identify early biomarkers that may suggest impairment in NO-related pathways. Materials and methods: This case-control study included a strictly selected cohort of 125 occupationally Pb-exposed workers and 125 healthy controls without known occupational exposure. To minimize confounding, all participants were strict nonsmokers and nondrinkers with no history of chronic disease. Blood Pb levels, hematological parameters, and metabolic biomarkers, including arginine, ADMA, SDMA, homoarginine, and citrulline, were analyzed using standardized laboratory methods. Associations between Pb levels, erythrocyte indices, and amino acid-related metabolites were evaluated using correlation analysis. Results: Blood Pb concentrations were significantly higher in the Pb-exposed group. Pb-exposed individuals had significantly lower hemoglobin (Hb) levels. While ADMA levels did not differ significantly between groups, SDMA levels were higher and citrulline levels were lower in the exposed workers. Ferritin levels were lower, whereas transferrin and total iron-binding capacity levels were higher in the exposed group. In multivariable analyses adjusted for age and body mass index, blood Pb levels were associated with higher SDMA levels and lower Hb, citrulline, and ferritin levels. Conclusion: Occupational Pb exposure was associated with alterations in erythrocytic indices and NO-related metabolic markers, which may be consistent with impairment in NO-related pathways. However, because of the case-control design and the absence of direct endothelial function measurements, these findings should be interpreted as associative rather than causal.