Comparative evaluation of zinc and copper levels in hair and serum across chronic diseases: implications for environmental and biological monitoring

The immune system, oxidative balance and physiological homeostasis all depend on trace metals, especially copper (Cu) and zinc (Zn). In comparison to healthy controls, the current study sought to assess the distribution of Zn and Cu in hair and serum among patients with tuberculosis, cataracts, diabetes mellitus, renal failure and dermatitis as well as to investigate their correlations with clinical and demographic factors. Atomic absorption spectrophotometry was used to measure the amounts of trace elements in 180 individuals. Nonparametric statistical tests were used since the data distribution was not normal. Zn and Cu levels varied significantly between disease groups (Zn: χ² = 21.774, p = 0.001; Cu: χ² = 125.254, p < 0.001). While Cu levels were higher in diabetes and tuberculosis. Cu exhibited no significant difference ( p = 0.845), whereas Zn levels were substantially greater in females than males ( p = 0.002), according to gender-based analysis. Hair had much greater quantities of both Zn and Cu than serum ( p < 0.001). Zn and Cu showed a substantial positive correlation ( r = 0.636, p < 0.001) and there were also significant correlations with hemoglobin levels and biological matrix. Receiver operating characteristic analysis revealed no discriminative capacity for Cu (AUC = 0.495, p = 0.895) and limited diagnostic capability for Zn (AUC = 0.602, p = 0.013). In summary, this work contributes to the understanding of trace element distribution in human populations and emphasizes the importance of integrating biological monitoring approaches when assessing environmental exposure and its potential health implications.