Randomized Controlled Trial
Copyright ©The Author(s) 2018. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Pharmacol Ther. Aug 7, 2018; 9(3): 22-30
Published online Aug 7, 2018. doi: 10.4292/wjgpt.v9.i3.22
Blood glucose response after oral intake of lactulose in healthy volunteers: A randomized, controlled, cross-over study
Jasmin Steudle, Christiane Schön, Manfred Wargenau, Lioba Pauly, Susann Schwejda-Güttes, Barbara Gaigg, Angelika Kuchinka-Koch, John F Stover
Jasmin Steudle, Christiane Schön, BioTeSys GmbH, Esslingen 73728, Germany
Manfred Wargenau, M.A.R.C.O. GmbH and Co. KG, Institute for Clinical Research and Statistics, Düsseldorf 40211, Germany
Lioba Pauly, Susann Schwejda-Güttes, John F Stover, Fresenius Kabi Deutschland GmbH, Oberursel 61440, Germany
Barbara Gaigg, Angelika Kuchinka-Koch, Fresenius Kabi Austria GmbH, Linz 4020, Austria
Author contributions: Steudle J and Schön C designed this study; the study was performed at the study site of BioTeSys under the supervision of Steudle J and Schön C; Wargenau M planned and performed statistical analysis; Steudle J and Schön C drafted the manuscript and made the final approval of the version to be published; Pauly L, Schwejda-Güttes S, Gaigg B, Kuchinka-Koch A and Stover JF planned and supervised this study, reviewed and approved the manuscript.
Institutional review board statement: The clinical study was approved by the ethics committee of the Landesärztekammer Baden-Württemberg, Germany.
Clinical trial registration statement: Clinicaltrials.gov. Identifier: NCT02968498.
Informed consent statement: After oral and written information, all volunteers participating in the study signed informed consent.
Conflict-of-interest statement: The study was sponsored by Fresenius Kabi Deutschland GmbH. The sponsors contributed to discussion about study design and selection of outcome measures prior to study start. Study realization, data analysis and report generation were independently undertaken by BioTeSys GmbH and M.A.R.C.O. GmbH and Co. KG. The authors from BioTeSys GmbH and M.A.R.C.O. GmbH and Co. KG declare that there is no conflict of interest regarding the publication of this paper.
Data sharing statement: No additional data are available.
CONSORT 2010 statement: The authors read the CONSORT 2010 Statement, and the manuscript was prepared and revised according to the CONSORT 2010 Statement.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: John F Stover, MD, Fresenius Kabi Deutschland GmbH, Borkenberg 14, Oberursel 61440, Germany. john.stover@fresenius-kabi.com
Telephone: +49-6172-6864598 Fax: +49-6172-6866330
Received: May 19, 2018
Peer-review started: May 19, 2018
First decision: June 14, 2018
Revised: July 3, 2018
Accepted: July 15, 2018
Article in press: July 16, 2018
Published online: August 7, 2018
Abstract
AIM

To investigate possible changes of blood glucose levels after oral intake of lactulose in healthy subjects.

METHODS

The study was performed as prospective, randomized, two-part study with 4-way cross-over design with n = 12 in each study arm. Capillary blood glucose levels were determined over a time period of 180 min after intake of a single dose of 10 g or 20 g lactulose provided as crystal or liquid formulation. During the manufacturing process of lactulose, impurities with sugars (e.g., lactose, fructose, galactose) occur. Water and 20 g glucose were used as control and reference. Because lactulose is used as a functional food ingredient, it may also be consumed by people with impaired glucose tolerance, including diabetics. Therefore, it is of interest to determine whether the described carbohydrate impurities may increase blood glucose levels after ingestion.

RESULTS

The blood glucose concentration-time curves after intake of 10 g lactulose, 20 g lactulose, and water were almost identical. None of the three applications showed any changes in blood glucose levels. After intake of 20 g glucose, blood glucose concentration increased by approximately 3 mmol/L (mean Cmax = 8.3 mmol/L), reaching maximum levels after approximately 30 min and returning to baseline within approximately 90 min, which was significantly different to the corresponding 20 g lactulose formulations (P < 0.0001). Comparing the two lactulose formulations, crystals and liquid, in the dosage of 10 g and 20 g, there was no difference in the blood glucose profile and calculated pharmacokinetic parameters despite the different amounts of carbohydrate impurities (1.5% for crystals and 26.45% for liquid). Anyhow, the absolute amount of single sugars was low with 0.3 g in crystals and 5.29 g in liquid formulation in the 20 g dosages. Lactulose was well tolerated by most volunteers, and only some reported mild to moderate mainly gastrointestinal side effects.

CONCLUSION

The unchanged blood glucose levels after lactulose intake in healthy subjects suggest its safe use in subjects with impaired glucose tolerance.

Keywords: Lactulose, Functional food ingredient, Sugar substitute, Blood glucose concentration

Core tip: Lactulose can be used as a functional food ingredient. During manufacturing as liquid or crystalline formulation, impurities with different sugars occur. Lactulose may also be consumed by people with impaired glucose tolerance, including diabetics. For these consumers, it is of interest whether the described carbohydrate impurities may increase blood glucose levels after ingestion. This study was performed to investigate possible changes of blood glucose levels after oral intake of 10 g and 20 g of liquid and crystalline lactulose in healthy subjects. The small amounts of carbohydrate impurities did not influence blood glucose levels, indicating potential applicability to people with impaired glucose tolerance.