Evaluation of subclinical inflammation withneutrophil lymphocyte ratio in heavy metal exposure

Aim: Neutrophil lymphocyte ratio (NLR) is being used frequently as a marker of subclinical inflammation. The objective of this study is to investigate the association between NLR levels and heavy metal levels in workers with lead exposure. Material and Method: Demographic and laboratory data of 1820 individuals with lead exposure were evaluated retrospectively. C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and complete blood count (CBC) were evaluated as inflammatory markers. Participants were cat-egorized into 3 groups according to blood lead levels as < 10 μg/dL (Group 1), 10-30 μg/dL (Group 2), and > 30 μg/dL(Group 3). The association between NLR and lead was evaluated by inter-group and correlation analysis. Results: Median NLR values of Group 1, Group 2 and Group 3 were 1.45 (1.57), 1.90 (6.44), and 1.96 (6.36) respectively (p<0.001). NLR correlated positively with blood lead levels (r=0.412; p<0.001). A positive correlation was also detected with CRP, ESR, white blood cell (WBC), neutrophil, and mean platelet vol-ume (MPV) levels (r=0.140; p<0.001, r=0.075; p=0.002, r=0.237; p<0.001, r=0.585; p<0.001, r=0.060; p<0.012, respectively). There was a negative cor-relation with lymphocyte (r= -0.536; p<0.001). Discussion: To our best knowl-edge, this study is the first one which shows a strong and dose-dependent association between NLR and lead levels.