NEW ORLEANS — Reduced serum selenium is an independent predictor of hypertension, according to an analysis of data from the third National Health and Nutrition Examination Surveys.
The findings from this and other studies, that serum selenium concentrations are reduced in African Americans, compared with those in with whites, may in part explain the increased incidence of hypertension in African Americans, Dr. Chizobam Ani said in a poster at a meeting sponsored by the International Society on Hypertension in Blacks.
Serum selenium is an essential component in substances shown to mediate the incidence of cardiovascular disease, such as glutathione peroxidase and homocysteine. In 9,881 nonpregnant participants aged 40 years and older, researchers noted significant differences in serum selenium concentrations between African Americans and whites at the highest and lowest quartile concentrations, reported Dr. Ani of Charles Drew University of Medicine and Science, Los Angeles.
On bivariate analysis, there was a significant association between serum selenium concentration and the prevalence of hypertension and other cardiovascular disease, including peripheral vascular disease, myocardial infarction, and congestive heart failure.
An analysis that controlled for known predictors of cardiovascular disease, including family history, diabetes, sociodemographic variables, and renal disease, showed a significant relationship between serum selenium and the prevalence of hypertension (odds ratio 1.30) and a significant interaction effect between ethnicity and serum selenium in individuals with hypertension (OR 1.10).
These findings are important because African Americans have higher rates of hypertension and mortality from heart disease and stroke than do whites and Hispanics in the United States, and because African American men have three times the risk of sudden death as do white men.
Based on the emerging understanding of the role of serum selenium in hypertension and cardiovascular disease, and the differing concentrations in African Americans and whites, Dr. Ani and his colleagues theorized that high serum concentrations of selenium might predict reduced levels of oxidate stress and vascular injury in certain ethnic groups that correlates with the incidence of cardiovascular diseases.
The current findings seem to support this theory of “differential oxidative protection for cardiovascular injury” in African Americans, compared with whites, he said in an interview. The findings are of interest because low serum selenium concentration is a modifiable risk factor, he said.