Plasma homocysteine levels increase in women during psychological stress

Homocysteine is an amino acid that has been strongly associated with vascular disease. Plasma homocysteine concentrations are known to vary with dietary patterns and to decrease with exogenous estrogen use, but no other behavioral factors have been examined as potential modifiers of this risk factor. Because psychological stress has also been implicated in the development of cardiovascular disease, the purpose of this study was to test the hypothesis that acute psychological stress induces elevations in plasma homocysteine concentrations. A secondary aim was to test potential differences in response between premenopausal and postmenopausal women. Thirty-four healthy women, one-half of whom were naturally postmenopausal with no hormone replacement, participated in this study. The psychological stressors included standard mental arithmetic and speech stressors. Blood samples were taken prior to, during, and after the stressors, and heart rate and blood pressure were also monitored. Results indicated significant elevations in plasma homocysteine during acute psychological stress, with a return to baseline concentrations during recovery. The pattern of findings for blood pressure and heart rate was similar, suggesting that the rise in homocysteine concentrations may have been sympathetically-mediated. No effects of menopausal status or endogenous estrogens were found. The findings provide preliminary evidence that plasma homocysteine may be an important factor in the relationship between psychological stress and risk for heart disease.