Association of Urinary and Dietary Selenium and of Serum Selenium Species with Serum Alanine Aminotransferase in a Healthy Italian Population

Abstract

The trace element selenium is of considerable interest due to its toxic and nutritional properties, which markedly differ according to the dose and the chemical form. It has been shown that excess selenium intake increases the risk of type 2 diabetes and, possibly, other metabolic diseases like hyperlipidemia and non-alcoholic fatty liver disease (NAFLD). For the latter, however, epidemiologic evidence is still limited. We carried out a cross-sectional study recruiting 137 healthy blood donors living in Northern Italy and assessed their exposure to selenium through different methods and measuring serum selenium species. We performed linear and spline regression analyses to assess the relation of selenium and its forms with serum alanine aminotransferase (ALT) levels, a marker of NAFLD. Urinary selenium levels were positively and somewhat linearly correlated with ALT (beta regression coefficient (β) 0.11). Conversely, the association of dietary selenium intake with ALT was positive up to 100 µg/day and null above that amount (β 0.03). Total serum selenium was inversely associated with ALT up to 120 µg/L, and slightly positive above that amount. Concerning the different serum selenium species, ALT positively correlated with two organic forms, selenocysteine (β 0.27) and glutathione peroxidase-bound selenium (β 0.09), showed a U-shaped relation with the inorganic tetravalent form, selenite, and an inverse association with human serum albumin-bound selenium (β −0.56). Our results suggest that overall exposure to selenium, and more specifically to some of its chemical forms, is positively associated with ALT, even at levels so far generally considered to be safe. Our findings add to the evidence suggesting that low-dose selenium overexposure is associated with NAFLD.

Daily Intake and Serum Levels of Copper, Selenium and Zinc According to Glucose Metabolism: Cross-Sectional and Comparative Study

“…However, a paucity of data exists regarding the possible relationship between trace element levels and glucose tolerance. The controversy is mainly from the small sample size and lack of or inadequate assessment of daily intake, as noted from the reported association studies [10][11][12][13][14]. Thus, additional studies with a better study design and a larger sample size are needed to address these issues properly.…”

Toxicological effects of selenium nanoparticles in laboratory animals: A review

“…Selenium species and compounds have been shown to increase oxidative stress, potentially resulting in toxic effects (Jablonska et al, 2016; Naderi et al, 2017). However, increasing selenium intake to levels required for optimal selenoprotein expression, specifically selenoprotein P expression, may have detrimental metabolic effects and increase the risk of type 2 diabetes and liver disease (Urbano et al, 2021; Vinceti, Filippini, Cilloni, Bargellini, et al, 2017; Vinceti et al, 2021; Wang et al, 2021).…”

Selenoprotein K contributes to CD36 subcellular trafficking in hepatocytes by accelerating nascent COPII vesicle formation and aggravates hepatic steatosis

“…Se treatment impairs insulin responsiveness and disrupts lipid profiles in animal models despite its insulin-like and antioxidant properties [ [56] , [57] , [58] , [59] ]. Furthermore, randomized clinical trials and observational studies have explored high Se may be linked to an increased risk of NAFLD [ [60] , [61] , [62] ]. Interestingly, we preliminarily analyzed the database of a transcriptome profile about fatty liver [ 63 ] and also found that the SelK gene had higher expression in steatosis and NASH groups than in healthy normal-weight controls.…”