Perets Tsachi Tsadok, Shporn Einav, Aizic Shoshana, Kelner Elena, Levy Sigal, Bareli Yifat, Pakanaev Lea, Niv Yaron, Dickman Ram
Laboratory of Gastroenterology, Rabin Medical Center, Beilinson Campus, Petach Tikva, Israel.
Dig Dis Sci. 2014 May;59(5):1012-6. doi: 10.1007/s10620-013-2980-7. Epub 2013 Dec 20.
The lactose breath test (LBT) is the standard technique for diagnosis of lactose malabsorption. However, it is time-consuming, strenuous for the patient and has been reported to have low sensitivity. The lactose intolerance quick test (LIQT) measures lactase activity in duodenal biopsies and may be performed as part of upper gastrointestinal endoscopy.
The purpose of this study was to assess the role of the LBT and LIQT in the case management of suspected lactose malabsorption.
The study group included 69 consecutive patients evaluated by the LBT followed by the LIQT. The test results were compared, and the sensitivity, specificity, and predictive values of the LBT were calculated.
Mean age of the patients was 54.4 years, male/female ratio was 1:3, and mean body mass index was 25.2. None had celiac disease on duodenal biopsy. The LIQT was positive for hypolactasia in 55 patients (80 %): mild in 14 (25 %) and severe in 41 (75 %); 10 (18 %) were symptomatic during the LBT. The LBT was positive for lactose malabsorption in 32 patients (46 %). Of the 37 patients with normal findings on the LBT, 24 (65 %) had positive findings on the LIQT: 11 (30 %) mild hypolactasia, 13 (35 %) severe hypolactasia. In one case, the LBT was positive and the LIQT was negative. The LBT had a sensitivity of 56 %, specificity 93 %, positive predictive value 97 %, and negative predictive value 35 %.
The LBT may serve as a diagnostic screening tool for lactose malabsorption. Symptomatic patients with negative LBT results should be referred for second-line testing with the LIQT.
乳糖呼气试验（LBT）是诊断乳糖吸收不良的标准技术。然而，该试验耗时较长，患者负担较重，且据报道其敏感性较低。乳糖不耐受快速试验（LIQT）可测量十二指肠活检组织中的乳糖酶活性，可作为上消化道内镜检查的一部分进行。
本研究旨在评估LBT和LIQT在疑似乳糖吸收不良病例管理中的作用。
研究组包括69例连续接受LBT然后进行LIQT评估的患者。比较试验结果，并计算LBT的敏感性、特异性和预测值。
患者的平均年龄为54.4岁，男女比例为1:3，平均体重指数为25.2。十二指肠活检均未发现乳糜泻。55例患者（80%）的LIQT结果显示乳糖酶缺乏呈阳性：轻度14例（25%），重度41例（75%）；10例（18%）在LBT期间出现症状。32例患者（46%）的LBT结果显示乳糖吸收不良呈阳性。在LBT结果正常的37例患者中，24例（65%）的LIQT结果呈阳性：轻度乳糖酶缺乏11例（30%），重度乳糖酶缺乏13例（35%）。有1例患者LBT结果为阳性而LIQT结果为阴性。LBT的敏感性为56%，特异性为93%，阳性预测值为97%，阴性预测值为35%。
LBT可作为乳糖吸收不良的诊断筛查工具。LBT结果为阴性的有症状患者应转诊进行LIQT二线检测。
