Reference intervals of serum copper, selenium, rubidium, zinc, and magnesium with evaluation of the influence of age, sex, and physical activity
Keywords:
reference intervals, inductively coupled plasma mass spectrometry, minerals, trace elements, serumAbstract
Environmental, lifestyle, and genomic factors contribute to the significant variability in trace element status among population groups from different geographical regions. This highlights the need to develop reliable regionally specific reference intervals (RIs). Currently, there is a lack of data on the RI of the element rubidium (Rb), as well as on inductively coupled plasma mass spectrometry (ICP-MS) verified RIs of copper (Cu), zinc (Zn), selenium (Se), and magnesium (Mg) in individuals of Bulgarian nationality. The present study aimed to establish population RIs for Cu, Zn, Se, Rb, and Mg, and to assess the influence age, gender, and physical activity. Materials and Methods: RIs were determined according to the guidelines of the Clinical and Laboratory Standards Institute CLSI EP28-A3c. The study included a reference group of 120 directly selected healthy volunteers of Bulgarian nationality (60 men and 60 women aged 18 to 65 years). Participants were divided into three groups: low (n = 29), medium (< 2 hours/week, n = 31), and high (> 2 hours/week, n = 60) physical activity. Serum levels of Cu, Zn, Se, Rb, and Mg were determined by ICP-MS. Results: The following RIs were determined: Mg: 0.65-0.99 mmol/L; Zn: 9.7-16.5 μmol/L; Se: 0.69-1.41 μmol/L, and Rb: 1.71-3.89 μmol/L. Statistically significant differences were found for Cu between men (10.7-19.2 μmol/L) and women (8.9-24.1 μmol/L), p = 0.003, as well as between women under and over 30 years of age (p = 0.001). Suboptimal Se concentration was found in 43% of the reference group, as well as zinc deficiency in 22% of men, and 10% of women. Conclusions: In this study, for the first time, RIs of Cu, Zn, Se, and Mg were verified by ICP-MS, and the RI of Rb was established for the Bulgarian population, with evaluation of the influence of gender, age, and physical activity.
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Copyright (c) 2026 D. Davcheva, G. Kirova, D. Terzieva, K. Simitchiev (Author)
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Journal Bulgarian Medical Journal (Български медицински журнал / Bulgarian Medical Journal)
