Alterations in serotonin metabolism in the irritable bowel syndrome. Issue 2 (5th November 2015)

• Record Type: Journal Article
• Authors: Thijssen, A. Y.; Mujagic, Z.; Jonkers, D. M. A. E.; Ludidi, S.; Keszthelyi, D.; Hesselink, M. A.; Clemens, C. H. M.; Conchillo, J. M.; Kruimel, J. W.; Masclee, A. A. M.
• Is Part Of: Alimentary pharmacology & therapeutics. Volume 43:Issue 2(2016)
• Page Start: 272
• Page End: 282
• Publication Date: 2015-11-05
• Subjects: Digestive organs -- Diseases -- Treatment -- Periodicals; Digestive organs -- Effect of drugs on -- Periodicals; Gastrointestinal system -- Diseases -- Treatment -- Periodicals; Gastrointestinal system -- Effect of drugs on -- Periodicals; 615.73
• DOI: 10.1111/apt.13459
• Languages: English
• ISSNs: 0269-2813

Abstract

Summary: Background: Alterations in serotonin (5‐HT) metabolism have been postulated to play a role in the pathogenesis of irritable bowel syndrome (IBS). However, previous reports regarding 5‐HT metabolism in IBS are contradicting. Aim: To compare platelet poor plasma (PPP) 5‐HT and 5‐hydroxyindole acetic acid (5‐HIAA) levels and their ratio in a large cohort of IBS patients and healthy controls (HC), including IBS‐subgroup analysis. Methods: Irritable bowel syndrome patients and HC were evaluated for fasting PPP 5‐HT and 5‐HIAA levels. Furthermore, GI‐symptom diary, GSRS, quality of life, anxiety and depression scores were assessed in the 2 weeks before blood sampling. Results: One hundred and fifty four IBS patients and 137 HC were included. No differences were detected in plasma 5‐HT between groups. The 5‐HIAA concentrations and 5‐HIAA/5‐HT ratio were significantly lower in IBS compared to HC: 24.6 ± 21.9 vs. 39.0 ± 29.5 μg/L ( P < 0.001) and 8.4 ± 12.2 vs. 13.5 ± 16.6 ( P < 0.01), respectively. Subtype analysis for 5‐HIAA showed all IBS subtypes to be significantly different from HC. The 5‐HIAA/5‐HT ratio was significantly lower in the IBS‐M subtype vs. HC. Linear regression analysis points to an influence of gender but not of GI‐symptoms, psychological scores or medication use. Conclusions: We demonstrated that fasting 5‐HT plasma levels are not significantly different in IBS patients compared to controls. However, decreased 5‐HIAA levels and 5‐HIAA/5‐HT ratio in IBS patients may reflect altered serotonin metabolism in IBS. Gender affects 5‐HIAA levels in IBS patients, but no effects of drugs, such as SSRIs, or higher GI‐symptom or psychological scores were found.