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

Teresa Urbano,Tommaso Filippini,Daniela Lasagni,Marco Vinceti,Annalisa Santachiara,Peter Grill,Silvia Fustinoni,Sabrina Sucato,Bernhard Michalke,Guy Djeukeu Noumbi,Roberto Baricchi,Elisa Polledri,Thelma A Pertinhez,Tiziana De Luca,Marcella Malavolti

doi:10.3390/antiox10101516

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.

Highlights

The human health effects of the trace element selenium continue to command attention in biomedical research, with particular reference to the involvement of selenium in chronic disease etiology due to its nutritional and toxicological properties [1]
Using the linear regression model, we found a positive association of dietary selenium and of urinary selenium concentrations with ALT, while total serum selenium concentrations were weakly and negatively associated with enzyme levels (Table 4)
3). while a negative andregression dietary selenium analysis, When we stratified the analysis by sex, we found a few relevant differences between association emerged for total serum selenium

Summary

Introduction

The human health effects of the trace element selenium continue to command attention in biomedical research, with particular reference to the involvement of selenium in chronic disease etiology due to its nutritional and toxicological properties [1]. Exposure to selenium mainly occurs through diet. It is abundant in offal, fish and seafood, cereals, and dairy products [2,3]. Selenium is a trace element of both toxicological and nutritional interest [1], with an uncertain but narrow, safe range of intake [6]. It is well recognized that the health effects and biological properties of selenium, including its nutritional and toxicological effects, considerably differ according to its chemical forms, whether inorganic or organic [7,8,9,10]. This is why it does not generally occur in its elemental state, except in relation to soil [11]. Its most common inorganic forms are selenides, selenite (SeO3 −2 , Se [+4]) and selenate (SeO4 −2 , Se [+6])

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Conclusion