Boyle P J, Scott J C, Krentz A J, Nagy R J, Comstock E, Hoffman C
Department of Medicine, University of New Mexico, Albuquerque 87131.
J Clin Invest. 1994 Feb;93(2):529-35. doi: 10.1172/JCI117003.
Systemic glucose utilization declines during sleep in man. We tested the hypothesis that this decline in utilization is largely accounted for by reduced brain glucose metabolism. 10 normal subjects underwent internal jugular and radial artery cannulation to determine cerebral blood flow by N2O equilibrium technique and to quantitate cross-brain glucose and oxygen differences before and every 3 h during sleep. Sleep stage was graded by continuous electroencephalogram, and systemic glucose turnover was estimated by isotope dilution. Brain glucose metabolism fell from 33.6 +/- 2.2 mumol/100 g per min (mean +/- SE) before sleep (2300 h) to a mean nadir of 24.3 +/- 1.1 mumol/100 g per min at 0300 h during sleep (P = 0.001). Corresponding rates of systemic glucose utilization fell from 13.2 +/- 0.8 to 11.0 +/- 0.5 mumol/kg per min (P = 0.003). Diminished brain glucose metabolism was the product of a reduced arteriovenous glucose difference, 0.643 +/- 0.024 to 0.546 +/- 0.020 mmol/liter (P = 0.002), and cerebral blood flow, 50.3 +/- 2.8 to 44.6 +/- 1.4 cc/100 g per min (P = 0.021). Brain oxygen metabolism fell commensurately from 153.4 +/- 11.8 to 128.0 +/- 8.4 mumol/100 g per min (P = 0.045). The observed reduction in brain metabolism occurred independent of stage of central nervous system electrical activity (electroencephalographic data), and was more closely linked to duration of sleep. We conclude that a decline in brain glucose metabolism is a significant determinant of falling rates of systemic glucose utilization during sleep.
人类睡眠期间全身葡萄糖利用率会下降。我们检验了这样一个假设，即利用率的下降主要是由于脑葡萄糖代谢降低所致。10名正常受试者接受颈内动脉和桡动脉插管，通过N₂O平衡技术测定脑血流量，并在睡眠前及睡眠期间每3小时定量测定脑葡萄糖和氧的差值。睡眠阶段通过连续脑电图进行分级，全身葡萄糖周转率通过同位素稀释法进行估算。脑葡萄糖代谢从睡眠前（23:00）的33.6±2.2 μmol/100g每分钟（平均值±标准误）降至睡眠期间03:00的平均最低点24.3±1.1 μmol/100g每分钟（P = 0.001）。相应的全身葡萄糖利用率从13.2±0.8降至11.0±0.5 μmol/kg每分钟（P = 0.003）。脑葡萄糖代谢减少是动静脉葡萄糖差值降低的结果，从0.643±0.024降至0.546±0.020 mmol/升（P = 0.002），以及脑血流量降低的结果，从50.3±2.8降至44.6±1.4 cc/100g每分钟（P = 0.021）。脑氧代谢相应地从153.4±11.8降至128.0±8.4 μmol/100g每分钟（P = 0.045）。观察到的脑代谢降低与中枢神经系统电活动阶段（脑电图数据）无关，且与睡眠时间更密切相关。我们得出结论，脑葡萄糖代谢降低是睡眠期间全身葡萄糖利用率下降的一个重要决定因素。
