Imai C, Muratani H, Kimura Y, Kanzato N, Takishita S, Fukiyama K
Third Department of Internal Medicine, University of the Ryukyus School of Medicine, Okinawa, Japan.
Am J Cardiol. 1998 Jun 1;81(11):1310-4. doi: 10.1016/s0002-9149(98)00163-5.
Postprandial hypotension and orthostatic hypotension occur often in elderly patients. In the present study, we examined hemodynamic and humoral responses to meal ingestion and active standing in 20 patients > or = 60 years of age who were free of apparent autonomic and cardiac dysfunction. For a time-control study, water was given instead of a meal to 19 of the 20 patients. After the meal ingestion, there was a fall in systolic blood pressure (BP) in 6 patients of > 20 mm Hg, whereas the fall in systolic BP during the control study was not > 20 mm Hg in any patient. The low-frequency power of the systolic BP wave, an index of peripheral sympathetic activity, was significantly increased only in the patients without postprandial hypotension. The postprandial changes in systolic BP were correlated with the changes in the low-frequency power of the systolic BP wave (r = 0.61; p < 0.01), but they were not correlated with the changes in plasma norepinephrine, insulin, cardiac output, or parameters obtained by the spectral analysis of the RR interval. The systolic BPs in the upright position were comparable after the meal and the water ingestion. Thus, the effects of meal ingestion and upright position on BP are not additive. Dysfunction of peripheral sympathetic control of vascular tone may contribute to the postprandial hypotension in elderly patients.
餐后低血压和体位性低血压在老年患者中经常发生。在本研究中，我们检查了20名年龄≥60岁且无明显自主神经和心脏功能障碍患者在进食和主动站立时的血流动力学和体液反应。作为一项时间对照研究，20名患者中有19名被给予水而非食物。进食后，6名患者的收缩压（BP）下降超过20 mmHg，而在对照研究中，任何患者的收缩压下降均未超过20 mmHg。收缩压波的低频功率是外周交感神经活动的一个指标，仅在无餐后低血压的患者中显著增加。餐后收缩压的变化与收缩压波低频功率的变化相关（r = 0.61；p < 0.01），但与血浆去甲肾上腺素、胰岛素、心输出量或RR间期频谱分析获得的参数变化无关。进食后和饮水后直立位的收缩压相当。因此，进食和直立位对血压的影响并非相加的。外周交感神经对血管张力的控制功能障碍可能导致老年患者餐后低血压。
