Department of Cardiovascular Medicine, Catholic University of Sacred Heart, Rome, Italy.
Eur J Prev Cardiol. 2012 Oct;19(5):908-13. doi: 10.1177/1741826711422765. Epub 2011 Sep 7.
Long-term shift work (SW) is associated with an increase in cardiovascular disease (CVD). Previous studies have shown that prolonged SW is associated with endothelial dysfunction, suggesting that this abnormality may contribute to the SW-related increase in cardiovascular risk. The immediate effect of SW on endothelial function in healthy subjects, however, is unknown.
We studied endothelial function and endothelium-independent function in 20 healthy specialty trainees in cardiology at our Institute, without any cardiovascular risk factor (27.3 ± 1.9 years, nine males), at two different times: (1) after a working night (WN), and (2) after a restful night (RN). The two test sessions were performed in a random sequence.
Endothelial function was assessed by measuring brachial artery dilation during post-ischaemic forearm hyperaemia (flow-mediated dilation, FMD). Endothelium-independent function in response to 25 µg of sublingual glyceryl trinitrate (nitrate-mediated dilation, NMD) was also assessed.
FMD was 8.02 ± 1.4% and 8.56 ± 1.7% after WN and RN, respectively (p = 0.025), whereas NMD was 10.5 ± 2.1% and 10.4 ± 2.0% after WN and RN, respectively (p = 0.48). The difference in FMD between WN and RN was not influenced by the numbers of hours slept during WN (<4 vs >4 hours) and by the duration of involvement of specialty trainees in nocturnal work (<12 vs >12 months).
Our study shows that in healthy medical residents, without any cardiovascular risk factor, FMD is slightly impaired after WN compared to RN. Disruption of physiological circadian neuro-humoral rhythm is likely to be responsible for this adverse vascular effect.
长期轮班工作（SW）与心血管疾病（CVD）的风险增加有关。先前的研究表明，长时间的 SW 与内皮功能障碍有关，这表明这种异常可能导致与 SW 相关的心血管风险增加。然而，SW 对健康受试者内皮功能的即时影响尚不清楚。
我们在本研究所对 20 名无心血管危险因素的心脏病学专业培训生（27.3±1.9 岁，男性 9 名）进行了内皮功能和内皮非依赖性功能研究，在两个不同时间点进行：（1）值夜班（WN）后，以及（2）休息一夜（RN）后。这两个测试序列以随机顺序进行。
通过测量缺血后前臂充血时肱动脉扩张（血流介导的扩张，FMD）来评估内皮功能。还评估了对 25μg舌下甘油三硝酸酯（硝酸盐介导的扩张，NMD）的内皮非依赖性功能。
WN 后 FMD 为 8.02±1.4%，RN 后为 8.56±1.7%（p=0.025），而 WN 和 RN 后 NMD 分别为 10.5±2.1%和 10.4±2.0%（p=0.48）。WN 和 RN 之间 FMD 的差异不受 WN 期间睡眠时间（<4 小时与>4 小时）和专业培训生参与夜间工作的时间（<12 个月与>12 个月）的影响。
我们的研究表明，在无任何心血管危险因素的健康内科住院医师中，与 RN 相比，WN 后 FMD 略有受损。生理昼夜神经激素节律的破坏可能是导致这种不良血管效应的原因。
