Body Selenium Status and Diabetes and Complications: The Multiphased Effect of Selenium

Area of Science:

• Biochemistry
• Nutritional Science
• Endocrinology

Background:

• Type 2 diabetes (T2D) is a significant global health concern.
• The role of selenium (Se) in T2D pathogenesis and complications remains incompletely understood.
• Recent research, including studies from China, necessitates a comprehensive review of Se's association with T2D.

Purpose of the Study:

• To comprehensively review and synthesize evidence from experimental, observational, Mendelian randomization (MR), and randomized controlled trials (RCTs) on selenium's role in T2D and its complications.
• To discuss the complex, often contradictory, findings and limitations in current research.
• To explore the implications for dietary recommendations regarding optimal selenium intake.

Main Methods:

• Integrated narrative synthesis and meta-analyses of diverse study types.
• Review of experimental data on Se intake and selenoprotein expression.
• Meta-analyses of observational, MR, and RCT data assessing Se status and T2D incidence and complications.

Main Results:

• Experimental data suggest supranutritional Se intake or abnormal selenoprotein expression may promote a T2D-like phenotype.
• Meta-analyses of observational and MR studies indicate a positive association between high Se status and increased T2D risk.
• Meta-analyses of RCTs do not support that Se supplementation increases T2D incidence.
• Growing evidence suggests high Se status may improve prognosis and reduce complications (cardiovascular disease, nephropathy, retinopathy, foot ulcers) in T2D patients.
• Se shows a positive association with metabolic dysfunction-associated steatotic liver disease but may protect against liver fibrosis.

Conclusions:

• The relationship between selenium and T2D is intricate, with high Se status potentially increasing risk but supplementation not being detrimental.
• Adequate selenium levels may offer benefits for managing T2D complications and related liver conditions.
• Further research is needed to establish optimal selenium intake ranges for preventing T2D and managing its complications.