Selenium level is associated withapoE ε4in rural elderly Chinese

Abstract

AbstractObjectiveSe is an essential trace element in human nutrition associated with antioxidant activity. Previous studies on predictors of toenail Se or serum Se have mostly concentrated on demographic factors such as age and gender. The present paper examines the association betweenapoEgenotype and Se levels in nail samples in a rural elderly Chinese cohort.DesignTwo thousand Chinese aged 65 years and over from four counties in China were enrolled in a cohort to study the association of Se with cognitive decline. Nail samples were collected from each participant and analysed for Se levels. Dietary Se intake was estimated from an FFQ using Se contents measured in food items collected from each village. Blood samples on filter cards were collected and analysed forapoEgenotype. Mixed-effect models were constructed with nail Se level as the dependent variable and each village as the random effect, which controlled for the potential confounding effect from correlation in Se measures obtained from participants residing in the same village.ResultsIn this elderly Chinese cohort, carriers of theapoE ε4allele had significantly lower Se levels measured in nail samples than non-carriers after adjusting for other significant covariates and controlling for estimated dietary Se intake. There was no significant difference between the two genotypes on estimated Se dietary intake (P= 0·6451).ConclusionsFuture studies are needed to examine the mechanism underlying the association between theapoE ε4allele and Se levels, including the role of oxidative stress and that of reduced lipid metabolism in theapoE ε4carriers.