Potential interference on the lipid metabolisms by serum copper in a women population: A repeated measurement study

Abstract

The relationship between excess copper (Cu) intake and lipid metabolic disorders is not well-studied, and most studies on this topic have a cross-sectional design. Here, we investigated the relationship between Cu exposure and blood lipid metabolism in women population, as well as potential mediation effects of oxidative stress and inflammation, using a repeated-measurement study. A total of 35 women in northern China were included, and each individual was visited for five times. Blood samples were collected, and the following serum biomarkers were analyzed: heme oxygenase-1 (HO-1), monocyte chemotactic protein-1 (MCP-1), interleukin (IL)-6, IL-8, and lipids [triglycerides (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL), high-density lipoprotein cholesterol (HDL), and lipoprotein(a) (Lp(a))]. A linear mixed-effect model was used to analyze the associations between Cu and the individual biomarkers in serum. The results showed that Cu was positively associated with TG (β = 0.0007, P = 0.01), TC (β = 0.0006, P = 0.002), LDL (β = 0.0004, P ≤ 0.001), and Lp(a) (β = 0.0004, P = 0.01), but not associated with HDL (β = 0.0001, P = 0.19). Likewise, serum Cu was positively associated with HO-1 (β = 0.0004, P = 0.03) and negatively associated with MCP-1 (β = −0.0006, P = 0.003) and IL-8 (β = −0.002, P = 0.03). Among the biomarkers of oxidative stress, inflammation, and lipids in serum, only IL-8 was negatively associated with HDL (β = −0.0004, P = 0.009). No other associations were observed. We conclude that high Cu exposure may elevate blood lipid levels as well as disturb processes related to oxidative stress and inflammation responses.