Lack of association between serum prolactin and lead exposure among battery workers

Objective: Serum prolactin (S-PRL) has been reported as a biomarker of early neurotoxic effect related to lead exposure. Raised S-PRL levels are generally considered to provide indirect evidence of reduced dopaminergic tuberoinfundibular (TIDA) activity. Elevated serum prolactin levels were reported due to lead-exposure. Our aim was to determine the relation between serum prolactin levels and lead-exposure. Material: Serum and whole blood samples were collected from 72 non-exposed and 35 lead-exposed male workers. Method: Blood lead was analyzed by Inductively Coupled Plasma - Mass Spectrometer. Serum prolactin levels were analyzed by immunological method. Serum alkaline phosphatase (ALP) and whole blood count were analyzed by using commercial kits. Results: Although serum prolactin levels were higher in control group compared to lead-exposed group (12.7 ± 7.5 vs. 11.8 ± 77), this difference was not statistically significant (p = 0.432). Mean corpuscular hemoglobin concentration (MCHC) was significantly higher in control group than lead-exposed group (p < 0.001) and reticulocyte distribution width (RDW) was significantly lower in control group than lead-exposed group (p = 0.031). Serum ALP levels were significantly higher in lead-exposed group than control group (197 ± 51 vs. 133 ± 65) (p = 0.000). According to Spearman correlation analysis, there was a significantly negative correlation between blood lead levels and MCHC (r = -0.373, p ≤ 0.001). Also, serum ALP levels were positively correlated with blood lead levels (r = 0.436, p ≤ 0.001). The correlation between blood lead levels and RDW was statistically weak (r = 0.225, p = 0.030). Conclusions: Serum prolactin level is not a diagnostic marker for determining the effect of lead-exposure.