Gastroenterology Unit, Department of Translational and Precision Medicine, Sapienza University of Rome, 00185 Rome, Italy.
LinkHealth Health Economics, Outcomes & Epidemiology S.R.L., 80143 Naples, Italy.
Nutrients. 2024 Oct 17;16(20):3516. doi: 10.3390/nu16203516.
Lactose malabsorption (LM) refers to the incomplete absorption of lactose in the small intestine, resulting in the arrival of ingested lactose in the colon, which can give rise to symptoms defined as lactose intolerance (LI). The lactose breath test (LBT), thanks to its low cost, availability, and noninvasiveness, is the most used diagnostic method. However, the LBT is a tedious tool, requiring prolonged involvement of patients, qualified staff, and infrastructure, of which the most time-consuming factor is the frequency and number of breath samples needed. : To simplify the current LBT methodology, compliant with the current guidelines' statements, by reducing the test duration or the number of breath samples, without compromising the test's accuracy. : The results of the standard LBT were compared with two simplified tests: a "shortened" test, lasting three hours, with samples taken every 30 min; and a "five-sample" test, lasting four hours, with samples taken every hour. Patients were stratified into three grades of malabsorption (mild, moderate, severe) based on the amount of gas exhaled. A clinical severity score was introduced to assess the clinical relevance of LI using a specific questionnaire. : Among the 543 patients enrolled (F 71.5%, mean age 43.7 ± 17.6 yrs), 60.4% (328/543) tested positive for LM. A total of 70.5% (383/543) presented LI, with 32.1% of those being true intolerants (LI without LM). The shortened test demonstrated an accuracy of 93.9%, with a sensitivity of 89.9% and a false negative rate of 10.1% (33/328). The five-sample test showed higher accuracy and sensitivity than the shortened test (96.5% and 94.2%, respectively; = 0.03) with a false negative rate of 5.8% (19/328). Of the 19 false negatives in the five-sample test, 95% (18/19) were categorized as mild malabsorbents. No statistical correlation was found between the clinical severity score and LBT results. : The five-sample test, involving hourly breath measurements, is a reliable option for simplifying the LBT without significantly reducing the procedure's sensitivity.
乳糖吸收不良（LM）是指小肠对乳糖的不完全吸收，导致摄入的乳糖到达结肠，从而引发乳糖不耐受（LI）的症状。乳糖呼气试验（LBT）由于其成本低、易于获得和非侵入性，是最常用的诊断方法。然而，LBT 是一种繁琐的工具，需要患者、合格的工作人员和基础设施的长期参与，其中最耗时的因素是所需的呼气样本的频率和数量。：为了简化当前的 LBT 方法，同时符合当前指南的声明，通过缩短测试持续时间或减少呼气样本数量，而不影响测试的准确性。：将标准 LBT 的结果与两种简化的测试进行比较：一种是持续三小时的“缩短”测试，每 30 分钟采集一次样本；另一种是持续四小时的“五样本”测试，每小时采集一次样本。根据呼出的气体量，患者被分为轻度、中度和重度吸收不良三个等级。引入了临床严重程度评分，使用特定问卷评估 LI 的临床相关性。：在纳入的 543 名患者中（女性占 71.5%，平均年龄 43.7±17.6 岁），60.4%（328/543）检测出 LM 阳性。共有 70.5%（383/543）出现 LI，其中 32.1%为真正的不耐受者（无 LM 的 LI）。缩短的测试显示出 93.9%的准确率，敏感性为 89.9%，假阴性率为 10.1%（33/328）。五样本测试显示出比缩短测试更高的准确性和敏感性（分别为 96.5%和 94.2%；=0.03），假阴性率为 5.8%（19/328）。在五样本测试中的 19 个假阴性中，95%（18/19）被归类为轻度吸收不良者。临床严重程度评分与 LBT 结果之间没有发现统计学相关性。：五样本测试，涉及每小时的呼气测量，是简化 LBT 而不显著降低该程序敏感性的可靠选择。
