Emerging roles of selenium on metabolism and type 2 diabetes

Abstract

Selenium is recognized as an essential element for human health and enters human body mainly via diet. Selenium is a key constituent in selenoproteins, which exert essential biological functions, including antioxidant and anti-inflammatory effects. Several selenoproteins including glutathione peroxidases, selenoprotein P and selenoprotein S are known to play roles in the regulation of type 2 diabetes. Although there is a close association between certain selenoproteins with glucose metabolism or insulin resistance, the relationship between selenium and type 2 diabetes is complex and remains uncertain. Here we review recent advances in the field with an emphasis on roles of selenium on metabolism and type 2 diabetes. Understanding the association between selenium and type 2 diabetes is important for developing clinical practice guidelines, establishing and implementing effective public health policies, and ultimately combating relative health issues.

Keywords: dietary intake; glucose and lipid metabolism; selenium; selenoproteins; type 2 diabetes.

FIGURE 1

Selenium contribution to total dietary selenium intake. Data for selenium contribution to total dietary selenium intake are adapted from published studies. Diet is the main source of selenium for human beings. The species of food, selenium content in food, as well as the amount taken in diet affect the daily selenium intake and selenium status.

FIGURE 2

Global estimated daily intake of selenium and prevalence of diabetes. Data for the global estimated daily selenium intake are adapted from the published studies (95-102). The selenium data of mainland China was selected. The selenium data of Africa was adapted from the Africa selenium daily supplied amount. Data for the prevalence of diabetes (data included until 2021) are derived from the Diabetes Atlas of the International Diabetes Federation (https://diabetesatlas.org/data/en/indicators/2/). Dashed lines are not supposed to accurately represent regions.

FIGURE 3

Relationship between selenium homeostasis and type 2 diabetes. Adequate selenium intake is very important for maintaining the homeostasis of glucose and lipid metabolism. Excessive or insufficient selenium intake will cause the increase or decrease of selenoproteins in the body, which in turn leads to a high risk of type 2 diabetes. The abnormal content of selenoproteins, including Gpx1, SelP, and SelS, may cause oxidative damage of β cells, insulin signaling impairment, endoplasmic reticulum stress and gluconeogenesis, which induce insulin secretion defects or insulin resistance. Therefore, it is recommended to supplement selenium according to the state of selenium.