The impact of anxiety on lactose intolerance symptoms

BACKGROUND Lactose malabsorption is variably associated with lactose intolerance (LI). The determinants of symptom onset have not yet been completely identified. Visceral sensitivity may play a role in the pathogenesis of functional symptoms; an increasing bulk of clinical and research data suggests the importance of the brain-gut interaction in intestinal bowel syndrome. AIM: To assess the impact of anxiety on LI symptoms, and the correlation between gas production during Lactose Breath test (LBT) and the intensity of gastrointestinal symptoms (GI) in anxious (A) and non-anxious (NA) patients. METHODS: LBT was carried out in 104 consecutive participants referred to our Gastroenterology Unit. GI symptoms were evaluated using the visual analogue scale (VAS: 0-10) throughout the LBT. All patients completed the HADS to determine anxiety. RESULTS LBT was positive in 70/104 (67%) participants; 49/ 104 (47%) showed significant anxiety symptoms (>10 items). In A subjects we did not find any significant correlation between gas levels and abdominal LI symptoms scores throughout the LBT. A subject showed higher scores for all LI symptoms as compared with other participants, independently of LBT results. NA pts with positive LBT showed higher scores for all LI symptoms, as compared to negative subjects. LIMITATIONS: The predominant gender is female but it is in agreement with literature data that show a preponderance of IBS in women. CONCLUSIONS: A status significantly influences the severity of all LI symptoms and does not strictly correlate with lactase deficiency. Conversely, among NA subjects LI symptoms increase along with H2 production. Anxiety seems to be a confounding factor in IBS pts.