Viani F, Verdú E F, Idström J P, Cederberg C, Fraser R, Fried M, Blum A L, Armstrong D
Division de Gastroentérologie, CHUV/PMU, Lausanne, Switzerland.
Digestion. 2002;65(1):2-10. doi: 10.1159/000051924.
Conventional techniques for measuring gastric acidity have demonstrated the decrease in gastric acidity produced by proton pump inhibitors (PPI); however, such techniques do not detect transient or localized pH changes which may modify the intragastric environment without affecting the therapeutic efficacy of PPIs.
To investigate local and temporal variations in intragastric pH and to test the hypothesis that omeprazole produces prolonged, generalized gastric anacidity (pH >6).
A single-blind study was conducted with triple-point 24-hour gastric pH-metry on days 7, 14 and 21 in 14 healthy, Helicobacter pylori-negative volunteers (7 M; 20-46 years) who received placebo for 7 days, followed by omeprazole 20 mg daily for 14 days.
Omeprazole increased the median 24-hour pH significantly in the distal corpus (placebo: 1.3 (95% CI 1.1 to 1.6); omeprazole week 1: 4.0 (2.6-5.0); omeprazole week 2: 4.0 (2.8-4.6)) and at all other gastric recording sites (p < 0.01). At both corpus sites, nocturnal pH was lower and mealtime pH was higher than the non-meal daytime pH during placebo and both omeprazole administration periods; in the antrum, however, the major difference noted was that meal-time pH was higher than non-meal daytime pH. Antral pH was lower during meals and higher at night than proximal corpus pH. During placebo, gastric pH >6.0 was observed at 1 site only for 1.7% (median; 95% CI 0.4-3.3%), at 2 sites simultaneously for 0.24% (0.0-1.0%) and at 3 sites for 0.0% (0.0-0.28%), respectively, of the recording periods; during the second week of omeprazole, the equivalent results were 7.7% (1.4-14.0%), 4.9% (0.21-15.7%) and 4.7% (0.0-9.9%), respectively.
Omeprazole, 20 mg daily, does not produce gastric anacidity despite significant increases in median 24-hour pH values. The time-, meal- and site-related variations in gastric pH observed under normal physiological conditions are seen to persist, with prolonged periods of low pH throughout the stomach and preservation of the normal, meal-related rise and nocturnal fall in gastric pH during omeprazole administration.
传统的测量胃酸度的技术已证实质子泵抑制剂（PPI）可降低胃酸度；然而，此类技术无法检测到短暂或局部的pH值变化，这些变化可能会改变胃内环境而不影响PPI的治疗效果。
研究胃内pH值的局部和时间变化，并验证奥美拉唑会产生持久、广泛的胃无酸状态（pH>6）这一假设。
对14名健康、幽门螺杆菌阴性的志愿者（7名男性；20 - 46岁）进行了一项单盲研究，在第7、14和21天进行24小时三点胃pH值测量。这些志愿者先服用7天安慰剂，随后每天服用20毫克奥美拉唑，持续14天。
奥美拉唑使胃体远端的24小时pH值中位数显著升高（安慰剂组：1.3（95%可信区间1.1至1.6）；奥美拉唑第1周：4.0（2.6 - 5.0）；奥美拉唑第2周：4.0（2.8 - 4.6）），在所有其他胃记录部位也是如此（p<0.01）。在胃体的两个部位，无论是在服用安慰剂期间还是服用奥美拉唑的两个阶段，夜间pH值较低，进餐时pH值高于非进餐白天的pH值；然而，在胃窦部，主要的差异在于进餐时pH值高于非进餐白天的pH值。进餐时胃窦部的pH值低于胃体近端，夜间则高于胃体近端。在服用安慰剂期间，胃pH>6.0在1个部位仅出现1.7%（中位数；95%可信区间0.4 - 3.3%）的记录时间，在2个部位同时出现0.24%（0.0 - 1.0%），在3个部位出现0.0%（0.0 - 0.28%）；在奥美拉唑治疗的第二周，相应结果分别为7.7%（1.4 - 14.0%）、4.9%（0.21 - 15.7%）和4.7%（0.0 - 9.9%）。
尽管24小时pH值中位数显著升高，但每天服用20毫克奥美拉唑并不会产生胃无酸状态。在正常生理条件下观察到的胃pH值与时间、进餐和部位相关的变化仍然存在，在整个胃中pH值长时间处于低水平，并且在服用奥美拉唑期间，与进餐相关的胃pH值正常升高和夜间下降得以保留。
