Safety and Effectiveness Study of a Fiber Supplement for Weight Loss

December 1, 2011 updated by: Joyce K Keithley, Rush University Medical Center

Safety and Efficacy of Glucomannan for Weight Loss

Overweight and obesity are serious and growing problems within the United States. The usual approaches to weight loss-dieting, exercise, and behavioral interventions-rarely result in long-term weight loss. Therefore, we will evaluate the safety and efficacy of glucomannan, a fiber supplement that has promising weight loss effects.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

The primary objective of this exploratory project is to evaluate the safety and efficacy of a highly viscous, water-soluble fiber supplement, glucomannan, for achieving weight loss in overweight and moderately obese individuals. Overweight and obesity are major public health problems in the U.S. that account for substantial morbidity, mortality, and healthcare costs. Conventional approaches to weight loss are largely ineffective, particularly for long-term weight loss and maintenance. Thus, there is a critical need for safe and effective adjunctive treatments. A few, limited studies suggest that glucomannan supplementation is associated with weight loss, is well-tolerated, and has a favorable safety profile.

In this preliminary study, the target population will be overweight and moderately obese individuals, a population that accounts for nearly 50% of all U.S. adults. The specific aims of the project are to: 1) describe the safety of glucomannan for achieving weight loss in overweight and moderately obese individuals, and 2) describe the efficacy of glucomannan for achieving weight loss in overweight and moderately obese individuals. Participants will take glucomannan supplements daily for eight weeks in a double-blind, placebo-controlled, randomized clinical trial. Safety and efficacy outcome measures include: gastrointestinal symptoms/tolerance, hepatic panel, serum creatinine, weight, body composition, diet intake, hunger/fullness, lipid profile, blood glucose, and C-reactive protein. Examination of the safety and efficacy of glucomannan for achieving weight loss will extend our understanding of additional treatments that may be effective in combating a significant public health problem.

Study Type

Interventional

Enrollment (Anticipated)

50

Phase

  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

    • Illinois
      • Chicago, Illinois, United States, 60612
        • Rush University Medical Center

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

14 years to 61 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • age > or = 18 and < or = 65 years
  • body mass index (BMI) > or = 25 and < or = 35 at study entry
  • speak and understand English (since translated versions of study tools have not been validated)
  • for females only: without childbearing potential or negative HCG hormone blood test and use of an appropriate form of contraception
  • signed informed consent form and HIPAA research authorization

Exclusion Criteria:

  • current use of fiber supplements or intolerance to fiber supplements
  • untreated/unstable metabolic conditions known to influence weight status (e.g., hypothyroidism, type 2 diabetes mellitus)
  • gastrointestinal disorders that might cause complications or influence motility or satiety (e.g., diverticulitis, inflammatory bowel disease, irritable bowel syndrome, intestinal narrowing or obstruction, difficulty swallowing)
  • Stage II hypertension (> or = 160/100 mg Hg) or dyslipidemia (fasting LDL cholesterol > or = 160 mg/dL; total cholesterol > or = 240 mg/dL; triglycerides > 200 mg/dL; HDL < or = 40 mg/dL)
  • fasting serum glucose > 126 mg/dL
  • acute or unstable cardiovascular, pulmonary, hepatic, renal, or psychiatric disorders
  • conditions for which weight loss may not be appropriate (e.g., HIV/AIDS, cancer)
  • use of medications that might affect weight or food absorption (e.g., diuretics, glucocorticoids, anorexigenic agents, Orlistat, laxatives)
  • use of CAM therapies that might affect weight (e.g., acupuncture, Hoodia)
  • weight change of > 5% body weight within 3 months of entry into the study
  • active eating disorders or active participation in a weight loss program
  • renal function impairment as evidenced by a history of renal disease or a serum creatinine > 2.0 mg/dL
  • liver function impairment as evidenced by a history of liver disease or liver enzyme elevations > three times the upper limit of normal (i.e., ALT > 150 u/L and/or AST > 165 u/L)
  • evidence of depression as determined by a weighted score of > or = 16 on the Center for Epidemiological Studies Depression Scale (CES-D), as this may affect eating behavior and adherence to the study protocol
  • currently consumes > or = 10 alcoholic drinks/week, as determined by self-report
  • currently smokes cigarettes due to the effects of nicotine on appetite and C-reactive protein levels
  • use of illicit drugs currently or in the last six months, as determined by self-report
  • for females only: pregnant, less than 6 months postpartum or 6 months post-termination of pregnancy, or currently lactating, due to lack of safety data in this population

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: 1
Two 665 mg capsules of glucomannan three times a day for eight weeks
Two 665 mg capsules of glucomannan three times a day for 8 weeks
Placebo Comparator: 2
Two capsules of inert microcrystalline cellulose three times a day for eight weeks
Two capsules of inert microcrystalline cellulose three times a day for eight weeks

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Weight loss
Time Frame: 8 weeks
8 weeks

Secondary Outcome Measures

Outcome Measure
Time Frame
C-reactive protein
Time Frame: 8 weeks
8 weeks
Lipid profile
Time Frame: 8 weeks
8 weeks
Fasting blood glucose
Time Frame: 8 weeks
8 weeks
Serum creatinine
Time Frame: 8 weeks
8 weeks
Body composition
Time Frame: 8 weeks
8 weeks
Dietary intake
Time Frame: 8 weeks
8 weeks
Hunger and fullness
Time Frame: 8 weeks
8 weeks
Gastrointestinal symptoms and tolerance
Time Frame: 8 weeks
8 weeks
Hepatic panel
Time Frame: 8 weeks
8 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Investigators

  • Principal Investigator: Joyce K Keithley, DNSc, RN, Rush University Medical Center

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

February 1, 2008

Primary Completion (Actual)

June 1, 2009

Study Completion (Actual)

July 1, 2009

Study Registration Dates

First Submitted

January 31, 2008

First Submitted That Met QC Criteria

February 12, 2008

First Posted (Estimate)

February 13, 2008

Study Record Updates

Last Update Posted (Estimate)

December 2, 2011

Last Update Submitted That Met QC Criteria

December 1, 2011

Last Verified

December 1, 2011

More Information

Terms related to this study

Other Study ID Numbers

  • RTF-GM

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.