Associations between Urinary and Dietary Selenium and Blood Metabolic Parameters in a Healthy Northern Italy Population.

Teresa Urbano,Sabrina Sucato,Tommaso Filippini,Claudia Baraldi,Roberto Baricchi,Silvia Fustinoni,Francesco Bruzziches,Elisa Polledri,Daniela Lasagni,Thelma A Pertinhez,Marco Vinceti,Annalisa Santachiara,Marcella Malavolti,Tiziana De Luca

doi:10.3390/antiox10081193

Abstract

Selenium is both an essential nutrient and a highly toxic element, depending on its dose and chemical forms. We aimed to quantify urinary selenium excretion and dietary selenium intake in 137 healthy non-smoking blood donors living in the northern Italian province of Reggio Emilia. We assessed selenium status by determining urinary selenium levels (mean 26.77 µg/L), and by estimating dietary selenium intake (mean 84.09 µg/day) using a validated semi-quantitative food frequency questionnaire. Fasting blood levels of glucose, lipids and thyroid-stimulating hormone were measured using automatized laboratory procedures. Dietary and urinary selenium were correlated (beta coefficient (β) = 0.19). Despite this, the association of the two indicators with health endpoints tended to diverge. Using linear regression analysis adjusted for age, sex, body mass index, cotinine levels and alcohol intake, we observed a positive association between urinary selenium and blood triglyceride (β = 0.14), LDL-cholesterol (β = 0.07) and glucose levels (β = 0.08), and an inverse one with HDL-cholesterol (β = −0.12). Concerning dietary selenium, a slightly positive association could be found with glycemic levels only (β = 0.02), while a negative one emerged for other endpoints. The two selenium indicators showed conflicting and statistically highly imprecise associations with circulating TSH levels. Our findings suggest that higher selenium exposure is adversely associated with blood glucose levels and lipid profile. This is the case even at selenium exposures not exceeding tolerable upper intake levels according to current guidelines.

Highlights

IntroductionA number of studies have tried to elucidate the controversial and intriguing role of the trace element selenium in human health
Introduction conditions of the Creative CommonsOver the last decades, a number of studies have tried to elucidate the controversial and intriguing role of the trace element selenium in human health
In a group of healthy adults, we investigated the relation between selenium exposure, as assessed through dietary intake and urinary excretion levels, and metabolic endpoints, including blood levels of glucose, total cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, triglycerides and thyroid-stimulating hormone

Summary

Introduction

A number of studies have tried to elucidate the controversial and intriguing role of the trace element selenium in human health. Antioxidants 2021, 10, 1193 plants [4], with a still uncertain balance between the two. Different choices have been made by different agencies based on very different rationales, while there is increasing awareness of the potential for low-dose selenium toxicity [5,6]. Several diseases and conditions have been linked to selenium deficiency and excess [6]

Objectives

Methods

Results

Discussion

Conclusion