“边吃边跑”的老年人可能会晕倒

餐后血压下降会增加站立时的压力损失

纽约——2000年10月3日——哥伦比亚长老会的研究人员发现，对于老年人来说，吃饭和站立都可能导致血压下降，尤其是两者结合时，可能导致跌倒甚至昏厥。哥伦比亚大学内科和外科医生学院医学系讲师Mathew Maurer博士说:“事实上，由于老年人每天要吃三顿饭，站三次，这可能是老年人昏倒的最常见原因。”Maurer博士和其他研究人员在2000年10月3日出版的《内科医学年鉴》上报告说，在接受测试的功能独立的老年人中，22%的人在吃饭和站直后都出现了低血压的影响。直立性低血压，即站立时血压下降，与老年人晕倒或跌倒的倾向有关。毛雷尔博士说:“我们知道老年人更容易患低血压，例如，站起来时血压会下降。”之前的研究还表明，老年人饭后坐着时血压也会下降。“饮食对血压的影响几乎只出现在老年人身上。在新闻中，你可能听说了参议员斯特罗姆·瑟蒙德(Strom Thurmond)本周末在一家餐馆吃饭后昏倒了。”毛雷尔博士引用这位97岁的政治家失去意识的例子作为这种现象的一个潜在例子。然而，尚不清楚餐后血压下降是否会放大突然升高的影响，还是只是增加了这种影响。毛雷尔博士和他的同事们通过测量老年、非残疾受试者的血压来验证这一观点。这些受试者被绑在一张倾斜的桌子上，分别在富含碳水化合物的热餐前或餐后30分钟测量血压。 "We've just shown that the two effects are additive, but not synergistic," says Dr. Maurer. When combined, the effects produced fainting in 22 percent of the participants in the study. To the elderly, co-author Dr. Daniel Bloomfield, assistant professor of medicine, advises, "If you find yourself lightheaded at times, you should be evaluated for low blood pressure." Dr. Maurer points out, "Although orthostatic hypotension can be treated with elastic stockings or medication, there isn't really a recommended treatment for postprandial hypotension." Dr. Maurer adds, "While a physician can cursorily assess the tendency for loss of blood pressure in these situations by questioning patients, definitive diagnosis requires thorough testing. This might involve use of postprandial [after-meal] measurement, preferably in conjunction with tilt-table tests like those used in our study." "Even when a physician measures a drop in blood pressure with standing of only 30 millimeters of mercury, this could become significant when combined with the effect of eating a meal," Dr. Bloomfield comments. Dr. Maurer emphasizes, "Healthcare professionals should be aware that because the elderly eat and stand three times a day, the cumulative risk for fainting can be very high." The study was funded by a grant from the National Institutes of Health and the American College of Cardiology.

# # #