Copper have been reported to be associated with
metabolic diseases. However, results on
copper exposure with blood
lipid profiles are inconsistent, and the underlying mechanisms of this association remain unclear. This study focused on investigating associations between urinary
copper and blood
lipid profiles; and exploring the potential role of systemic
inflammation in such relationships. Concentrations of urinary
copper, plasma
C-reactive protein (CRP), and four blood
lipid parameters (e.g., Total
cholesterol [TC],
triglycerides [TG],
low-density lipoprotein cholesterol [
LDL-C], and
high-density lipoprotein cholesterol [HDL-C]) were measured in the adult participants from Wuhan-Zhuhai cohort. The associations between
copper, CRP, and four blood
lipids were assessed by the multivariable linear regression models, and the 3D mesh graphs was used to examine the joint effects of
copper exposure and CRP on four blood
lipid parameters. In addition, we used mediation analysis to investigate the mediated effects of CRP in the relationships between
copper exposure and blood
lipid profiles. Each 1% increase in urinary
copper was statistically significantly associated with a 5.32% (95% CI: 2.48%, 8.24%) increase in TG after adjusting for the confounders (P < 0.05). No significant associations were observed between urinary
copper and the other three blood
lipid parameters (all P > 0.05). In addition, urinary
copper increased monotonically with plasma CRP elevation, which in turn, was positively associated with TC, TG, and
LDL-C and negatively related to HDL-C (all P < 0.05). Results from 3D mesh graphs demonstrated that increased levels of plasma CRP with higher urinary
copper corresponded to higher TC, TG,
LDL-C, and lower HDL-C concentrations. Mediation analysis observed that CRP mediated 6.27% in the relationships of urinary
copper and TG. These findings suggest that systemic
inflammation partly mediated the association between
copper exposure and abnormal blood
lipid, and may contribute to the development of
dyslipidemias.