在流行地区，50 克剂量诊断的乳糖吸收不良不如 25 克剂量评估临床不耐受和预测对停奶的反应。

Lactose malabsorption diagnosed by 50-g dose is inferior to assess clinical intolerance and to predict response to milk withdrawal than 25-g dose in an endemic area.

机构信息

Department of Gastroenterology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India.

出版信息

J Gastroenterol Hepatol. 2013 Sep;28(9):1462-8. doi: 10.1111/jgh.12273.

DOI:10.1111/jgh.12273

PMID:23701423

Abstract

BACKGROUND

Lactose malabsorption (LM), diagnosed currently using lactose hydrogen breath and tolerance tests (LHBT, LTT) with a high, nonphysiological dose (50-g), may mimic irritable bowel syndrome (IBS). In LM-endemic areas, clinically significant malabsorption (lactose intolerance) may be better diagnosed using a lesser dose, and positive results so obtained may predict response to milk withdrawal more effectively.

METHODS

Fifty patients each with IBS (Rome III) were evaluated using LHBT and LTT with 50-g, 25-g, and 12-g lactose. Sensitivity and specificity of LHBT and LTT with different dosages (gold standard: lactase gene C/T-13910 polymorphism) and symptom development were evaluated. Effect of milk withdrawal was studied.

RESULT

Of 150 patients, 37/50 (74%) and 28/50 (56%) had LM by LHBT and LTT using 50-g lactose; 41/50 (82%) and 31/50 (62%) had LM using 25-g lactose, and 14/50 (28%) and 29/50 (58%) using 12-g lactose, respectively. Sensitivity and specificity of LHBT using 50-g, 25-g, and 12-g lactose were 92.6%, 52.0%, and 94%, 60%, and 36.4%, 88.2%, and those of LTT, 92%, 80.0%, and 84.8%, 82.4%, and 66.7%, 58.8%, respectively. Breath hydrogen correlated with lactose dose. Though patients developing symptoms with 50-g lactose exhaled more hydrogen than those remaining asymptomatic, hydrogen levels did not differ following 25-g and 12-g dosages in relation to symptom development. Patients' milk intake was 335 ± 92 mL/d (≈ 16.7 ± 9.6-g lactose). Positive LHBT using 25-g dose better predicted symptom resolution than by 50-g and 12-g lactose.

CONCLUSION

Twenty-five gram is the ideal dose of lactose for LHBT and LTT in LM-endemic areas.

摘要

背景

目前，乳糖吸收不良（LM）通过使用高剂量（50g）的乳糖氢呼气和耐量试验（LHBT、LTT）进行诊断，可能会模仿肠易激综合征（IBS）。在 LM 流行地区，使用较小剂量可能更能诊断出有临床意义的吸收不良（乳糖不耐受），并且阳性结果可能更有效地预测对停奶的反应。

方法

使用 50g、25g 和 12g 乳糖对 50 例符合罗马 III 标准的 IBS 患者进行 LHBT 和 LTT。评估 LHBT 和 LTT 的不同剂量（金标准：乳糖酶基因 C/T-13910 多态性）的敏感性和特异性以及症状发展，并研究停奶的效果。

结果

在 150 例患者中，50 例患者中 37 例（74%）和 28 例（56%）通过 50g 乳糖的 LHBT 和 LTT 显示 LM；41 例（82%）和 31 例（62%）通过 25g 乳糖的 LHBT 和 LTT 显示 LM，14 例（28%）和 29 例（58%）通过 12g 乳糖的 LHBT 和 LTT 显示 LM。使用 50g、25g 和 12g 乳糖的 LHBT 的敏感性和特异性分别为 92.6%、52.0%和 94%、60%和 36.4%、88.2%和 84.8%；LTT 的敏感性和特异性分别为 92%、80.0%和 84.8%、82.4%和 66.7%、58.8%。呼气氢与乳糖剂量相关。尽管 50g 乳糖组中出现症状的患者呼出的氢气多于无症状患者，但在 25g 和 12g 剂量下，症状发展与氢气水平无差异。患者的牛奶摄入量为 335±92mL/d（≈16.7±9.6-g 乳糖）。25g 剂量的阳性 LHBT 比 50g 和 12g 乳糖更好地预测症状缓解。