Mental stress induces transient endothelial dysfunction in humans

Background-Mental stress has been linked to increased morbidity and mortali ty in coronary artery disease and to atherosclerosis progression. Experimen tal studies have suggested that damage to the endothelium may be an importa nt mechanism. Methods and Results-Endothelial function was studied in 10 healthy men (age d 50.4+/-9.6 years) and in 8 non-insulin-dependent diabetic men (aged 52.0/-7.2 years). Brachial artery flow-mediated dilation (FMD, endothelium depe ndent) and response to 50 mug of sublingual glyceryl trinitrate (GTN, endot helium independent) were measured noninvasively by use of high-resolution u ltrasound before and after (30, 90, and 240 minutes) a standardized mental stress test. The same protocol without mental stress was repeated on a sepa rate occasion in the healthy men. In healthy subjects, FMD (5.0+/-2.1%) was significantly (P<0.01) reduced at 30 and 90 minutes after mental stress (2 .8+/-2.3% and 2.3+/-2.4%, respectively) and returned toward normal after 4 hours (4.1+/-2.0%). Mental stress had no effect on the response to GTN. In the repeated studies without mental stress, FMD did not change. The diabeti c subjects had lower FMD than did the control subjects (3.0+/-1.5% versus 5 .0+/-2.1%, respectively; P=0.02) but showed no changes in FMD (2.7+/-1.1% a fter 30 minutes, 2.8+/-1.9% after 90 minutes, and 3.1+/-2.3% after 240 minu tes) or GTN responses after mental stress, Conclusions-These findings suggest that brief episodes of mental stress, si milar to those encountered in everyday life, may cause transient (up to 4 h ours) endothelial dysfunction in healthy young individuals. This might repr esent a mechanistic link between mental stress and atherogenesis.