Serum total homocysteine concentration determinants in non-Hispanic White, non-Hispanic Black, and Mexican-American populations of the United States

Abstract

Objective: Blood vitamins and the association between serum total homocysteine (tHcy) concentration and demographic, socioeconomic, health and lifestyle factors were investigated in non-Hispanic Whites (NHW), non-Hispanic Blacks (NHB), and Mexican Americans (MA).

Design and setting: Cross-sectional data from the third National Health and Nutrition Examination Survey, 1988-1994, was used.

Participants: The study included 2,258 NHW, 1,856 NHB, and 1,584 MA.

Main outcome measures: Relationship between serum tHcy (dependant variable), and sex, age, income, education, alcohol consumption, vitamin/mineral supplement and medicine use, body mass index (BMI), systolic and diastolic blood pressures, serum creatinine, cotinine (a measure of smoking), folate and cobalamin, and red blood cell (RBC) folate (independent variables) was analyzed with multivariate analysis of covariance and linear regression.

Results: Serum tHcy was significantly higher in NHW and NHB than in MA. Serum and RBC folate were significantly higher and serum cobalamin was significantly lower in NHW compared to their counterparts. Serum folate and serum creatinine were the strongest determinants of tHcy in NHB and MA, and in NHW, respectively. The BMI was negatively associated with tHcy in NHB (P=.02) and in MA (P=.002) but not in NHW. Systolic blood pressure and serum cotinine were positively associated with tHcy only in NHW and MA. Education, income, supplement and medicine use, and alcohol consumption were not associated with tHcy concentration in any race-ethnicities.

Conclusions: In this large population based study, regardless of race-ethnicity, age, serum creatinine, folate, and cobalamin, and RBC folate were the major determinants of serum tHcy.