Red blood cell folate is a well-established indicator of folate intake. However, studies focused on the 
association between red blood cell (RBC) folate and coronary heart disease (CHD) are limited. The aim of the current study, published July 2017 in Nutrition, Metabolism and Cardiovascular Diseases, was to investigate the effect of RBC folate concentrations on the presence of CHD in a nationally representative sample of American adults.
Red Blood Cell Folate Study Methods
In 1999-2012 National Health and Nutrition Examination Survey (NHANES), 22,499 subjects aged 30 to 74 years with RBC folate concentrations, CHD status and responses to co-variates questions were included; 822 (3.65%) participants were identified as having CHD. Bio-Rad Quanta Phase II radioassay and microbiological assay were used to measure RBC folate concentrations.
- First, the researchers treated RBC folate as a categorical variable, based on RBC folate tertiles, and used logistic regression analysis to display the RBC folate and CHD relationship.
2. Second, they explored associations using a combination of restricted cubic spline and logistic regression models, stratified by sex.
3. And, after adjusting for several well-established traditional CHD risk factors, RBC folate was positively related to CHD presence in the total population and the association was more pronounced among males than females. A J-shaped pattern was observed in RBC folate concentrations for males.
Outcomes
Conclusion
Elevated RBC folate concentrations were associated with higher CHD risk. Further investigation is needed to test the association in large-scale follow-up studies.
