Rosenthal M J, Argoud G M
GRECC, Veterans Administration Medical Center, Sepulveda, California.
J Gerontol. 1989 Mar;44(2):M57-61. doi: 10.1093/geronj/44.2.m57.
To determine whether the dawn phenomenon occurs in healthy elderly subjects, we compared glucose and insulin levels as well as glucose production rates in 10 young nondiabetic men (mean age 26 +/- 3 years) and 10 old nondiabetic men (mean age 69 +/- 3 years) between 0500 to 0800. Young subjects demonstrated a modest but significant rise in plasma glucose level (89 +/- 1 mg/dl to 92 +/- 1 mg/dl, p less than .05) and glucose production rate (1.7 +/- 0.1 mg/kg/min to 1.9 +/- 0.2 mg/kg/min, p less than .05) between 0540 and 0800. No rise was detected in the plasma glucose or glucose production rate in older subjects as a group, between these times. However, a few elderly subjects did display a dawn glucose rise. Changes in plasma insulin levels were not significant for either young or old subjects. Older subjects had significantly lower mean peak growth hormone levels during the night than young subjects (6.7 +/- 1.3 vs 10.1 +/- 1.6 ng/ml, p less than .05). These results demonstrate a modest rise in plasma glucose levels and glucose production rate in healthy young subjects consistent with previous reports of the dawn phenomenon. This modest early morning glucose rise is absent in most otherwise healthy older subjects.
为了确定健康老年受试者是否会出现黎明现象，我们比较了10名年轻非糖尿病男性（平均年龄26±3岁）和10名老年非糖尿病男性（平均年龄69±3岁）在05:00至08:00之间的血糖、胰岛素水平以及葡萄糖生成率。年轻受试者在05:40至08:00之间血浆葡萄糖水平有适度但显著的升高（从89±1mg/dl升至92±1mg/dl，p<0.05），葡萄糖生成率也有升高（从1.7±0.1mg/kg/min升至1.9±0.2mg/kg/min，p<0.05）。在这个时间段内，老年受试者作为一个整体，其血浆葡萄糖或葡萄糖生成率没有检测到升高。然而，有少数老年受试者确实出现了黎明时血糖升高的情况。年轻和老年受试者的血浆胰岛素水平变化均不显著。老年受试者夜间的平均峰值生长激素水平显著低于年轻受试者（6.7±1.3对10.1±1.6ng/ml，p<0.05）。这些结果表明，健康年轻受试者的血浆葡萄糖水平和葡萄糖生成率有适度升高，这与之前关于黎明现象的报道一致。在大多数其他方面健康的老年受试者中，这种适度的清晨血糖升高并不存在。
