Diagnosis of lactose intolerance and the "nocebo" effect: the role of negative expectations.

摘要: Background: Diagnosis of lactose intolerance is based on a “positive” H2 breath test associated with abdominal symptoms. The present study established to what extent the occurrence symptoms during “negative” may result from “nocebo effect” instead lack sensitivity procedure. Methods: Between 2005 and 2007, 636 outpatients performed standard 4-h 25 g tolerance test. was positive in 254, negative 325, 57 patients were “non-producers”. Twenty-seven reporting despite underwent “sham” following ingestion 1 glucose. Fifty-four presenting documented used as controls. Results: Twelve out 27 (44.4%), unexpectedly also 14 (25.9%) controls presented sham difference between two groups not significant (P < 0.15) OR 2.28; C.I. 0.77–6.78. Conclusion: In most instances, reported by H2BT cannot be attributed false-negative Instead, non-organic component, resulting expectations (“nocebo effect”) likely implicated. Moreover, diagnosed intolerant, need for restricting primary source dietary calcium should critically reconsidered. © 2010 Editrice Gastroenterologica Italiana S.r.l. Published Elsevier Ltd. All rights reserved.