Clinical Scholarship Differences in Mexican American and Non-Hispanic White Veterans’ Homocysteine Levels Carol M. Baldwin, Iris R. Bell, Anna Giuliano, Mary Z. Mays, Pete Arambula, Andrei Alexandrov Purpose: To compare homocysteine (Hcy) levels and possible modulatory factors, such as nu- trient or supplement intake, between Mexican American and Non-Hispanic White (NHW) male military veterans scoring at high- versus low-risk for stroke. Design: A cross-sectional survey with a high and low stroke risk biomarkers substudy. Methods: Voluntary participants were Mexican American (n=109) and NHW (n=120) vet- eran outpatients 54 to 85 years of age at a Southwestern Veterans Administration (VA) medical center. Measures included food frequency, health history, and stroke risk scale de- rived from the Framingham Study. Biomarker subgroups, 30 Mexican American and 30 NHW, half of each group scoring high or low on stroke risk, who were tested for morning fasting blood levels of Hcy, B12, and folate. Findings: In the cross-sectional study (n=229), nutrient intake was comparable between ethnic groups. In the substudy, Mexican Americans (n=30) with high or low stroke risk scores and NHW (n=30) with high stroke risk scores had elevated Hcy levels (12.5; 11.9; 11.4 μmol/L respectively) compared to NHW veterans with low stroke risk scores (7.8 μmol/L) even after controlling for age, education, folate, diabetes, and smoking pack-years (p=.001). Mexican Americans compared to NHW were significantly more likely to be in the preclinical (17% versus 3% >10 μmol/L) and clinical ranges (69% versus 35% >15 μmol/L) for Hcy. Conclusions: Mexican Americans showed higher levels of Hcy whether they scored high or low for stroke, and greater representation in clinical and preclinical Hcy ranges compared to NHW veterans. The Framingham-derived, predominantly NHW population-based stroke risk measure might require ethnically relevant stroke risk factors for Mexican Americans. JOURNAL OF NURSING SCHOLARSHIP, 2007; 39:3, 235–242. C 2007 SIGMA THETA TAU INTERNATIONAL. [Key words: Arizona Food Frequency Questionnaire, Framingham Stroke Risk, homocysteine, Mexican American, non-Hispanic White, veterans] * * * H omocysteine (Hcy), a sulfur-containing amino acid, is a precursor for synthesis of the amino acid me- thionine and a product of methionine metabolism that requires folate and vitamins B6 and B12 as cofac- tors (Stead, Jacobs, Brosnan, & Brosnan, 2004). Genetic polymorphisms for enzymes that regulate Hcy metabolism, low intake or levels of B vitamins such as vitamins B12, B6, and folic acid, older age, medications such as statin drugs, methotrexate and L-dopa, renal or thy- roid dysfunction, postmenopausal status in women, and lifestyle habits such as smoking and alcohol or caffeine intake, can contribute to elevations in plasma Hcy (Cof- fey, Crowder, & Cheek, 2003; Dierkes, Westphal, & Lu- ley, 2004; Malinow, Bostom, & Krauss, 1999; Warren, 2002). Plasma Hcy is associated with cardiovascular dis- ease (CVD) including atherosclerosis, myocardial infarc- Carol M. Baldwin, RN, PhD, AHN-BC, Associate Professor and Southwest Borderlands Scholar, Beta Upsilon, Arizona State University College of Nursing & Healthcare Innovation, Southwest Borderlands, and the South- ern Arizona VA Health Care System, Tucson, AZ; Iris R. Bell, MD, PhD, Professor, University of Arizona Department of Family and Community Medicine, and the Southern Arizona VA Health Care System, Tucson, AZ; Anna Giuliano, PhD, Professor, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL; Mary Z. Mays, PhD, Associate Professor, Arizona State University College of Nursing & Healthcare Innovation, Pete Aram- bula, MA, Research Assistant, Southern Arizona VA Health Care System, Tucson, AZ; Andrei Alexandrov, MD, Director, Stroke Research Center Bar- row Neurological Institute, Phoenix, AZ. We thank the veterans who made this study possible. This study was supported, in part, by a Department of Veterans Affairs VISN 18 Minority Vascular Center grant, and NIH NHLBI cooperative agreement supplement U01HL53938-07S1. Correspondence to Dr. Baldwin, Director, Office of International Health, Scientific and Ed- ucational Affairs, Arizona State University, College of Nursing & Health- care Innovation, 500 North 3rd Street, Phoenix, AZ 85004-0698. E-mail: carol.baldwin@asu.edu Accepted for publication March 8, 2007. Journal of Nursing Scholarship Third Quarter 2007 235