Sci Transl Med：缺觉和昼夜倒班可能增加患糖尿病风险

4月12日，美国研究人员日前完成的一项研究显示，对缺觉、昼夜倒班的员工或其他生物钟失调者而言，昼夜节律紊乱可能损害身体制造胰岛素的能力并增加患糖尿病的风险。

波士顿布里格姆妇科医院的研究者奥菲尤·巴克斯顿等人让21名健康试验对象在受控环境中度过近6周。其间，试验对象的饮食和活动水平保持稳定。在研究开始阶段，每名试验对象保持正常作息规律。在随后3周内，他们每24小时只睡眠五六个小时，睡眠有时在白天，有时在黑夜，以模拟昼夜倒班员工的作息时间。研究人员随后还通过改变试验对象的睡眠时间，模拟4小时航空飞行时差的影响。在研究结束前，试验对象通过9个夜晚的“修复睡眠”恢复正常作息。

研究人员发现，在睡眠缺乏及作息紊乱期间，试验对象分泌胰岛素的胰腺细胞受到影响，他们饭后的血糖水平明显提升，在某些情况下处于糖尿病前期水平。此外，试验对象的静止代谢率——即维持呼吸、血液循环等基本生理功能所燃烧热量的速度下降。据估算，下降水平相当于试验对象在饮食和活动习惯不变的情况下体重一年增加10磅（约合4．54公斤）以上。不过，上述有害影响在试验对象完成修复睡眠后大部分得到逆转。

相关研究报告11日发表在美国学术期刊《科学·转化医学》Science Translational Medicine网络版上。研究者巴克斯顿介绍说，这些结果支持了此前的发现——在糖尿病前期人群中，昼夜倒班员工比白班员工更易患上糖尿病，因为前者通常白天入睡较困难，因而面临生物钟紊乱和睡眠不足的双重困境。不过，巴克斯顿强调，这一试验在受控环境中进行，与现实情况有区别，而且样本数量过少，尚不能得出昼夜倒班会增加患糖尿病风险这一结论。（生物谷Bioon.com）

doi:10.1126/scitranslmed.3003200
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Adverse Metabolic Consequences in Humans of Prolonged Sleep Restriction Combined with Circadian Disruption

Orfeu M. Buxton1,2,*, Sean W. Cain1,2, Shawn P. O’Connor1, James H. Porter1, Jeanne F. Duffy1,2, Wei Wang1,2, Charles A. Czeisler1,2 and Steven A. Shea1,2

Epidemiological studies link short sleep duration and circadian disruption with higher risk of metabolic syndrome and diabetes. We tested the hypotheses that prolonged sleep restriction with concurrent circadian disruption, as can occur in people performing shift work, impairs glucose regulation and metabolism. Healthy adults spent >5 weeks under controlled laboratory conditions in which they experienced an initial baseline segment of optimal sleep, 3 weeks of sleep restriction (5.6 hours of sleep per 24 hours) combined with circadian disruption (recurring 28-hour “days”), followed by 9 days of recovery sleep with circadian re-entrainment. Exposure to prolonged sleep restriction with concurrent circadian disruption, with measurements taken at the same circadian phase, decreased the participants’ resting metabolic rate and increased plasma glucose concentrations after a meal, an effect resulting from inadequate pancreatic insulin secretion. These parameters normalized during the 9 days of recovery sleep and stable circadian re-entrainment. Thus, in humans, prolonged sleep restriction with concurrent circadian disruption alters metabolism and could increase the risk of obesity and diabetes.