Division of Gastroenterology, Hepatology and Nutrition, Vanderbilt University Medical Center, 1301 22nd Avenue South, Nashville, TN 37232-5280, USA.
Clin Gastroenterol Hepatol. 2012 Aug;10(8):874-8. doi: 10.1016/j.cgh.2011.12.032. Epub 2012 Jan 5.
BACKGROUND & AIMS: Obesity is believed to be an important etiologic factor in gastroesophageal reflux disease. However, it is not clear how obesity might affect esophageal acid exposure in patients with extraesophageal manifestations of reflux.
We conducted a cross-sectional study of 223 patients with extraesophageal symptoms suspected of being related to reflux. Participants underwent endoscopy and 48-hour wireless pH testing. The percentage of time at a pH of less than 4 (total, upright, and supine) was measured for each patient, and data were compared with corresponding body mass index (BMI), as continuous and categoric variables (normal, 18.5 to <25; overweight, 25 to <30; and obese, >30). Multivariable linear regression was used to identify variables associated with percentage of total time at a pH less than 4. The primary predictor of interest was BMI; age, sex, esophagitis, and hiatal hernia status were considered potential confounders or precision variables.
Esophageal acid exposure was associated significantly (P < .001) with BMI. The percentage of time at a pH less than 4 and total symptomatic reflux events increased significantly (P = .005) with increasing BMI. The relationship between percentage of time at a pH less than 4 and BMI was nonlinear and S-shaped. With BMI ranges, the percentage of time at a pH less than 4 increased by 0.23% (normal BMI), 0.75% (overweight), and 0.07% (obese) for every 1-kg/m(2) increase in BMI (P < .001).
Increases in esophageal acid exposure are greatest among overweight patients and plateau in obese patients. The findings have implications for benefit of weight loss in patients with suspected extraesophageal manifestations of gastroesophageal reflux disease.
肥胖被认为是胃食管反流病的一个重要病因。然而，肥胖如何影响有食管外反流表现的患者的食管酸暴露程度尚不清楚。
我们对 223 例有食管外症状且怀疑与反流有关的患者进行了横断面研究。参与者接受了内镜检查和 48 小时无线 pH 检测。测量每位患者的 pH 值小于 4 的时间百分比（总时间、直立位和仰卧位），并将数据与相应的体重指数（BMI）作为连续和分类变量（正常，18.5 至<25；超重，25 至<30；肥胖，>30）进行比较。多变量线性回归用于确定与 pH 值小于 4 的总时间百分比相关的变量。主要预测指标是 BMI；年龄、性别、食管炎和食管裂孔疝状态被认为是潜在的混杂因素或精度变量。
食管酸暴露与 BMI 显著相关（P<0.001）。pH 值小于 4 的时间百分比和总症状性反流事件的百分比随着 BMI 的增加而显著增加（P=0.005）。pH 值小于 4 的时间百分比与 BMI 之间的关系是非线性和 S 形的。在 BMI 范围内，每增加 1kg/m2，pH 值小于 4 的时间百分比增加 0.23%（正常 BMI）、0.75%（超重）和 0.07%（肥胖）（P<0.001）。
超重患者的食管酸暴露增加最大，肥胖患者的食管酸暴露增加趋于平稳。这些发现对有食管外胃食管反流病表现的患者减肥获益有影响。
