Urine selenium concentration is a useful biomarker for assessing population level selenium status

Area of Science:

• Nutritional Biochemistry
• Biomarker Development
• Public Health Surveillance

Background:

• Plasma selenium (Se) concentration is a recognized biomarker for Se status, particularly in deficient populations.
• Urinary Se excretion correlates with dietary intake, suggesting urine Se concentration as a potential biomarker.
• Limited data exist on urine Se concentration in Se-deficient populations.

Purpose of the Study:

• To evaluate urine Se concentration as a viable biomarker for assessing Se status in a large sample of Malawian women and children.
• To determine if urine Se concentration reflects population-level Se status, particularly in potentially Se-deficient groups.

Main Methods:

• Analysis of casual urine samples (n=1406) from women of reproductive age (WRA) and school-aged children (SAC) in Malawi (2015/16 DHS).
• Selenium concentration in urine measured using inductively coupled plasma mass spectrometry (ICP-MS).
• Urinary dilution corrections applied for specific gravity, osmolality, and creatinine; plasma Se status data also utilized.

Main Results:

• Between-cluster variation in urine Se concentration correlated with plasma Se concentration.
• Corrected urine Se concentrations better explained between-cluster variations in plasma Se than uncorrected data.
• No significant variation observed between households within a cluster or individuals within a household.

Conclusions:

• Urine selenium concentration is a viable biomarker for population-level Se status surveillance in certain groups, particularly in Malawi.
• This approach offers a cost-effective alternative when urine samples are already collected for other health assessments.
• Findings support the use of urine Se in public health initiatives for monitoring nutritional status.