Analysis of the relationship between the blood concentration of several metals, macro- and micronutrients and endocrine disorders associated with male aging

Abstract

Beyond 30 years of age, men experience a decline in the production of testosterone, yet only a few develop late-onset hypogonadism. This study was designed to determine the relationship between blood concentrations of metals, macro- and micronutrients and age-related testosterone deficiency and associated hormonal changes in aging men. The research involved 313 men aged 50-75 years. We used ELISA to determine the concentrations of total testosterone (TT), free testosterone (FT), estradiol (E2), dehydroepiandrosterone sulfate (DHEAS) and sex hormone-binding globulin (SHBG). We calculated free androgen index (FAI). With the use of emission spectrometry in inductively coupled argon plasma, we determined the whole-blood concentrations of lead (Pb), cadmium (Cd), mercury (Hg), arsenic (As) and tungsten (W), as well as serum concentrations of magnesium (Mg), iron (Fe), calcium (Ca), copper (Cu), zinc (Zn), selenium (Se), chromium (Cr), manganese (Mn) and molybdenum (Mo). The study showed no relationship between TT and FT and the concentrations of metals. Men with TT deficiency had significantly lower concentrations of Mg and Fe and increased Mn. Men with FT deficiency had higher W and Cr levels and lower Fe. Assessing the correlation between the concentrations of hormones, SHBG and FAI, and the concentration of metals and macro- and microelements in the blood of the men, we found positive correlations between the concentrations of TT-Mg, TT-Fe, TT-Mo, FT-Fe, E2-As, SHBG-Mn, FAI-W, FAI-As, FAI-Zn and FAI-Ca, and negative correlations between the concentrations of TT-Mn, FT-Cd, FT-Cr, E2-Hg, E2-Cr, SHBG-W, SHBG-As, SHBG-Zn, SHBG-Ca, FAI-Pb and FAI-Mn. Positive correlations between As and E2 and between As and FAI may suggest a lack of association between this metal and hypogonadism in people not exposed to excess As levels. Our research indicates a positive relationship between the concentrations of Mg, Fe and Zn and endocrine system in aging men, in contrast to Mn and Cr. Toxic metals (Cd, Pb) seemed to negatively affect the level of bioavailable testosterone. In persons not exposed to As, As does not contribute late-onset hypogonadism. Heavy metals (Pb, Cd, Hg and W) may contribute to a lower concentration of DHEAS. The role of W in men with LOH was found to be ambiguous, as on the one hand its concentration was higher in men with FT deficiency, and on the other hand it positively correlated with FAI, which in turn indirectly indicates testosterone availability. Copper and selenium do not seem to play any significant role in the occurrence of TT deficiency in aging men.

Keywords: Androgen deficiency; Blood levels of metals; Macroelements; Microelements.