Leadbetter Guy, Keyes Linda E, Maakestad Kirsten M, Olson Sheryl, Tissot van Patot Martha C, Hackett Peter H
Department of Exercise Physiology, Mesa State College, Grand Junction, CO, USA.
Wilderness Environ Med. 2009 Spring;20(1):66-71. doi: 10.1580/08-WEME-BR-247.1.
To determine the efficacy of 2 different sources of Ginkgo biloba extract (GBE) in reducing the incidence and severity of acute mountain sickness (AMS) following rapid ascent to high altitude.
Two randomized, double-blind, placebo-controlled cohort studies were conducted in which participants were treated with GBE (240 mg x d(-1)) or placebo prior to and including the day of ascent from 1600 m to 4300 m (ascent in 2 hours by car). Acute mountain sickness was diagnosed if the Environmental Symptom Questionnaire III acute mountain sickness-cerebral (AMS-C) score was > or =0.7 and the Lake Louise Symptom (LLS) score was > or =3 and the participant reported a headache. Symptom severity was also determined by these scores.
Results were conflicting: Ginkgo biloba reduced the incidence and severity of AMS compared to placebo in the first but not the second study. In the first study, GBE reduced AMS incidence (7/21) vs placebo (13/19) (P = .027, number needed to treat = 3), and it also reduced severity (AMS-C = 0.77 +/- 0.26 vs 1.59 +/- 0.27, P = .029). In the second study, GBE did not reduce incidence or severity of AMS (GBE 4/15 vs placebo 10/22, P = .247; AMS-C = 0.48 +/- 0.13 vs 0.58 +/- 0.11, P = .272). The primary difference between the 2 studies was the source of GBE.
The source and composition of GBE products may determine the effectiveness of GBE for prophylaxis of AMS.
确定两种不同来源的银杏叶提取物（GBE）在快速上升到高海拔地区后降低急性高原病（AMS）发病率和严重程度的疗效。
进行了两项随机、双盲、安慰剂对照队列研究，参与者在从1600米上升到4300米当天及之前接受GBE（240毫克×d⁻¹）或安慰剂治疗（乘车2小时上升）。如果环境症状问卷III急性高原病-脑型（AMS-C）评分≥0.7且路易斯湖症状（LLS）评分≥3且参与者报告头痛，则诊断为急性高原病。症状严重程度也由这些评分确定。
结果相互矛盾：在第一项研究中，与安慰剂相比，银杏叶降低了AMS的发病率和严重程度，但在第二项研究中没有。在第一项研究中，GBE降低了AMS发病率（7/21）与安慰剂（13/19）相比（P = 0.027，治疗所需人数 = 3），并且还降低了严重程度（AMS-C = 0.77 ± 0.26对1.59 ± 0.27，P = 0.029）。在第二项研究中，GBE没有降低AMS的发病率或严重程度（GBE 4/15对安慰剂10/22，P = 0.247；AMS-C = 0.48 ± 0.13对0.58 ± 0.11，P = 0.272）。两项研究之间的主要差异是GBE的来源。
GBE产品的来源和成分可能决定GBE预防AMS的有效性。
