Hydrogen breath test for the diagnosis of lactose intolerance, is the routine sugar load the best one

• Published in: World journal of gastroenterology : WJG Vol. 14; no. 40; pp. 6204 - 6207
• Main Authors: Argnani, Fiorenza, Di Camillo, Mauro, Marinaro, Vanessa, Foglietta, Tiziana, Avallone, Veronica, Cannella, Carlo, Vernia, Piero
• Format: Journal Article
• Language: English
• Published: United States The WJG Press and Baishideng 28.10.2008
• Subjects: Administration, Oral; Breath Tests; Humans; Hydrogen - metabolism; Lactose - administration & dosage; Lactose - pharmacokinetics; Lactose Intolerance - diagnosis; Lactose Intolerance - metabolism; Lactose Tolerance Test; Predictive Value of Tests; Rapid Communication; 乳糖不耐性; 乳糖吸收不良; 乳糖酶缺乏; 氢呼吸测试
• ISSN: 1007-9327; 2219-2840
• DOI: 10.3748/wjg.14.6204

AIM： To evaluate the prevalence of lactose intolerance （LI） following a load of 12.5 g in patients diagnosed as high-grade malabsorbers using the hydrogen breath test （HBT）-25. METHODS： Ninety patients showing high-grade malabsorption at HBT-25 were submitted to a second HBT with a lactose load of 12.5 g. Peak hydrogen production, area under the curve of hydrogen excretion and occurrence of symptoms were recorded. RESULTS： Only 16 patients （17.77%） with positive HBT-25 proved positive at HBT-12.5. Hydrogen production was lower as compared to HBT-25 （peak value 21.55 parts per million （ppm） ± 29.54 SD vs 99.43 ppm ± 40.01 SD; P 〈 0.001）. Symptoms were present in only 13 patients. The absence of symptoms during the high-dose test has a high negative predictive value （0.84） for a negative low-dose test. The presence of symptoms during the first test was not useful for predicting a positive low-dose test （positive predictive value 0.06-0.31）. CONCLUSION： Most patients with a positive HBT-25 normally absorb a lower dose of lactose and a strict lactose restriction on the basis of a ＂standard＂ HBT is, in most instances, unnecessary. Thus, the 25 g lactose tolerance test should probably be substituted by the 12.5 g test in the diagnosis of LI, and in providing dietary guidelines to patients with suspected lactose malabsorption/intolerance.