Long-Term Excessive Selenium Supplementation Induces Hypertension in Rats

Area of Science:

• Environmental Health
• Toxicology
• Nutritional Science

Background:

• Selenium (Se) is an essential trace element vital for biological functions, found naturally in the environment and food.
• While dietary intake typically meets requirements, selenium supplementation is common, raising concerns about potential toxicity from excess intake.
• The effects of long-term selenium supplementation on cardiovascular health, specifically blood pressure, require further investigation.

Purpose of the Study:

• To investigate the impact of chronic sodium selenite supplementation on systolic blood pressure (SBP) in rats.
• To assess the effects of selenium exposure on the redox status and selenium levels in various tissues.

Main Methods:

• Male Wistar rats received sodium selenite (2 and 6 mg/L) in drinking water for 85 days.
• Systolic blood pressure (SBP) and body weight were monitored weekly.
• Oxidative stress biomarkers were analyzed in blood/plasma, and selenium levels were measured in blood, plasma, kidney, and liver.

Main Results:

• Selenium supplementation significantly elevated SBP in rats from day 42 onwards compared to controls.
• No significant changes in oxidative stress biomarkers were observed, despite increased SBP.
• Elevated selenium levels were detected in whole blood, kidney, and liver tissues of supplemented rats.

Conclusions:

• Long-term selenium supplementation can lead to increased systolic blood pressure in rats.
• The mechanism for SBP increase may involve pathways beyond selenoprotein synthesis, warranting further research.
• Caution is advised regarding selenium supplementation due to potential adverse effects on blood pressure, especially since supplements are often available without prescription.