Elevated Blood Selenium Level has a Non-Linear Association with Risk of Anemia in U.S.A. Adults: Data from the NHANES...

Only a few epidemiological studies have reported the association between blood selenium and the prevalence of anemia. To date, the evidence is limited and inconsistent.

We enrolled 9,335 participants (≥ 20 years) who participated in the National Health and Nutrition Examination Survey (NHANES) from 2011 to 2016 to assess the link between blood selenium and the risk of anemia. Multivariate logistic regression analysis and a generalized additive model (GAM) was applied to assess the relationship between blood selenium and anemia risk.

We found a significant adverse association between blood selenium and the prevalence of anemia after adjusting for all potential covariates (OR = 0.98, 95% CI: 0.97, 0.98, p < 0.001). After a sequence of sensitive analyses, the conclusion remains stable (p for trend < 0.001). However, a non-linear relationship was detected based on GAM. We calculated a turning point of 205.89 μg/L using a two-piecewise linear regression model.

When blood selenium level is lower than 205.89 μg/L, blood selenium level is inversely associated with the risk of anemia. Our results provide a new strategy to reduce the risk of anemia.