Gender‐specific distribution of selenium to serum selenoproteins: Associations with total selenium levels, age, smoking, body mass index, and physical activity

Abstract

The epidemiology of selenium (Se) is mainly based on the determination of total serum selenium levels (TSe) which by many aspects is an inadequate marker of Se status. In this study we applied a recently developed LC-ICP-MS method, for the determination of the selenium content of the three main serum selenium-containing proteins, in a subcohort of the ATTICA study. This enables us to investigate whether the selenium distribution to selenoproteins may correlate with demographic (age, gender) and lifestyle variables (smoking, physical activity) that are crucial for the development of chronic diseases. A sub-sample from the ATTICA Study, consisted of 236 males (40 ± 11 years) and 163 females (38 ± 12 years), was selected. The selenium content of glutathione peroxidase (GPx-3), selenoprotein P (SelP) and selenoalbumin (SeAlb) was determined in serum by LC-ICP/MS method. We found that 26% of TSe is found in GPx-3, 61% in SelP and 13% in SeAlb. We have assessed the different ratios of selenoproteins' selenium content (Se-GPX-3/Se-SelP, Se-GPX-3/Se-SeAlb, Se-SelP/Se-SeAlb), showing that people with similar TSe may have different distribution of this selenium to selenoproteins. Total selenium levels and gender are the variables that mostly affect selenium distribution to selenoproteins while age, smoking, physical activity and BMI do not significantly influence selenium distribution. In conclusion, the simultaneous determination of the selenium content of serum selenium-containing selenoproteins is necessary for a thorough estimation of selenium status. The ratio of the Se content between selenoproteins may be proven a novel, valid marker of selenium status.

Sex-specific and inter-individual differences in biomarkers of selenium status identified by a calibrated ELISA for selenoprotein P

“…It was therefore highly interesting to observe that the correlations of Se and SELENOP concentrations differ between the sexes, and that the correlation was poorest in young women. Differences in Se distribution to GPX3 and SELENOP and a varying Se-content in albumin were noted before in men and women in an epidemiological study [43]. It is reported that GPX3 is more highly expressed in healthy females than in males [44], and that alcohol consumption increased total Se in women but not in men [45].…”

Diet-Induced Obesity in the Selenocysteine Lyase Knockout Mouse

“…1A). Both male and female Scly KO mice presented similar aggravated obesity; however, we selected male mice to be further analyzed in our study, as gender-specific mechanisms were found to regulate energy metabolism (58) and selenium metabolism (33,54). Body weight differences between Scly KO and WT mice were significantly increased after 7 weeks on a high-fat diet (Fig.…”

Selenium speciation in human serum and its implications for epidemiologic research: a cross-sectional study

“…Methodological limitations of the former approach have been discussed in detail [6][7][8]18,49,50], including the general use of total selenium concentration instead of determination of individual Se species [19,51]. This limitation, also a consequence of the analytical complexities and the high costs Table 3 Crude and adjusted regression analysis of total serum Se and individual Se species in all subjects (n = 50) in relation to age, sex, body mass index, smoking and Se supplement use.…”

“…Inadequate exposure assessment, particularly long-term, in addition to unmeasured confounding due to lifestyle and environmental factors and to genetic factors including selenoprotein polymorphisms, has been suggested to explain the conflicting results yielded by observational studies, and may have severely hampered the possibility to reliably identify the health effects of the metalloid. Among the potential pitfalls of the exposure assessment methods, a key role is played by the inability of overall tissue Se levels to adequately reflect exposure to specific selenium compounds [8,19]. In fact, this element is usually present in environmental sources and in living organisms in various inorganic and organic forms, having considerable and even extreme variations in both toxicological and physiological properties [4,15,[20][21][22][23][24][25][26][27][28], and little is known in the human about the relation of these Se species to each other and more generally with the overall Se level.…”