Raymid García-Fernández

PubMed2004

Estrogen does not prevent endothelial dysfunction caused by cigarette smoking.

BACKGROUND: Estrogen favors endothelial function while acute tobacco use provokes dysfunction. Previous studies have not examined the effect of smoking one cigarette at different stages of the menstrual cycle. HYPOTHESIS: Favorable actions of estrogen on endothelial function are transitorily abolished by smoking one cigarette. METHODS: Brachial artery endothelium-dependent dilation was measured noninvasively before, 10 min, and 1 h after smoking in 17 healthy premenopausal women. Studies were done in the first 3 days (early stage) and repeated between Days 9 and 13 of the menstrual cycle (middle stage). Estradiol was measured after each study. RESULTS: At basal conditions, women in the middle stage of their cycles, when estradiol was 20 times higher than in the early stage, had significantly more endothelial-dependent brachial dilatation. No difference in the marked depression caused by cigarette smoking was found between the two stages. One h recuperation was complete in both phases. CONCLUSION: Cigarette smoking abolishes the protection of circulating estrogen on endothelial function.

Adult↗

PubMed2002

[Endothelial dysfunction in cardiologists after 24 hours on call].

The objective was to determine if the stress caused by 24 hours on call in a cardiology emergency room alters endothelial function assessed by high-resolution ultrasonography in the brachial artery. Fifteen young physicians were studied in a crossover design: a) after a normal night of sleep at home, and b) after 24 hours on call without sleeping in an emergency room. Both studies were made at rest, 5 minutes after forearm occlusion and 3 minutes after administration of sublingual nitroglycerin. High-resolution ultrasonography and a 7.5-MHz linear array transducer were used to measure the brachial artery lumen. After 24 hours on call, physicians had significantly higher resting systolic and diastolic blood pressure. They also had a non-significant increase in heart rate and a lower brachial artery diameter. Brachial artery dilatation caused by hyperemia was only 3.35%, while it increased to 11.34% after normal sleep (p < 0.001). Only 2 physicians showed more than 4.4% dilatation, which was considered a normal response, while 13 had more than 4.4% after a normal night of sleep at home (p < 0.01). The response to nitroglycerin was similar under control conditions and after 24 hours of duty oncall.In conclusion, stress caused by 24 hours on call in a cardiology emergency room depresses or abolishes endothelial function.

Adult↗