OPTIFIT-Optimal Fiber Trial for Diabetes Prevention

This study has been completed.
Charite University, Berlin, Germany
German Diabetes Foundation, Munich, Germany
Klinikum Ernst von Bergmann Augenklinik Laserzentrum
University Hospital Tuebingen
Information provided by (Responsible Party):
Prof. Dr. med. Andreas F. H. Pfeiffer, German Institute of Human Nutrition
ClinicalTrials.gov Identifier:
First received: September 5, 2012
Last updated: February 4, 2015
Last verified: February 2015
High intake of insoluble fiber is strongly associated with a reduced incidence of diabetes and cardiovascular events in prospective observation studies. Our primary objective is to compare a life style diabetes prevention program(PRAEDIAS) with and without added insoluble fibers in its effectiveness to prevent incident diabetes type 2 in high risk individuals with impaired glucose tolerance. Subjects with IGT not willing to participate in the intervention will be used as independent controls. Secondary aims are to identify mechanisms of action with regard to body composition, anti-inflammatory and metabolic effects of fibers. We propose a randomized, prospective intervention study. The results will be of general relevance for guidance of fiber intake in the population and will help the food industry to design healthy high fiber foods. Fiber can be added at low cost to numerous foods. Increased fiber intake may therefore provide a simple non-cognitive prevention strategy effective at the population level.

Condition Intervention
Nutrition Disorders
Metabolic Syndrome x
Body Weight
Glucose Metabolism Disorders
Metabolic Diseases
Dietary Supplement: Fiber
Dietary Supplement: Placebo

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Caregiver, Investigator)
Primary Purpose: Prevention
Official Title: Investigation of the Effect of Insoluble Dietary Fiber on Carbohydrate and Lipid Metabolism and the Prevention of Diabetes Mellitus Type 2 in Subjects With Impaired Glucose Tolerance

Resource links provided by NLM:

Further study details as provided by German Institute of Human Nutrition:

Primary Outcome Measures:
  • Change of 2h-postprandial blood glucose from IGT to diabetes mellitus type 2 or normal glucose tolerance (NGT) [ Time Frame: 0, 12, 24 months ] [ Designated as safety issue: No ]
    Change of the glucose metabolism (OGTT)

Secondary Outcome Measures:
  • Change of insulin sensitivity [ Time Frame: 0, 12, 24 months ] [ Designated as safety issue: No ]
    Measurement by HOMA and OGIS from the OGTT

  • Change of insulin secretion [ Time Frame: 0, 12, 24 months ] [ Designated as safety issue: No ]
    Measurement by the OGTT

  • Expression of inflammatory markers in blood [ Time Frame: 0, 6, 12, 18, 24 months ] [ Designated as safety issue: No ]
    CRP, leukocytes, adipocytokines

  • Biometric data [ Time Frame: 0, 6, 12, 18, 24 months ] [ Designated as safety issue: No ]
    Nutritional impact of blood pressure, anthropometry (body weight and body composition)

  • Assessment of cognitive performance [ Time Frame: 0, 12, 24 months ] [ Designated as safety issue: No ]
  • Development of indices for the prediction of fat mass [ Time Frame: 0, 12, 24 months ] [ Designated as safety issue: No ]
    Change of fat fraction in liver, abdominal and in the total body fat measuring by MRI/H1-spectroscopy

  • Determination of gene expression in adipose tissue [ Time Frame: 0, 12, 24 month ] [ Designated as safety issue: No ]
    Determination of inflammatory and other transcripts in sc adipose tissue in a fat biopsy.

Estimated Enrollment: 200
Study Start Date: May 2010
Study Completion Date: December 2014
Primary Completion Date: December 2014 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Drink enriched in fibers
7,5g enriched fiber drinks, BID
Dietary Supplement: Fiber
200ml drinks enriched with 7,5g of fiber (90% insoluble fiber, 10% soluble fiber), BID, over 24 months
Experimental: Placebo drink
Placebo drink, BID
Dietary Supplement: Placebo
200ml Placebo, BID, over 24 months

Detailed Description:
The overall objective is to investigate whether insoluble fibers added to standard nutrition can reduce the progression of impairment of glucose metabolism in a high risk population with impaired glucose metabolism. Large prospective cohort studies clearly show that mainly insoluble cereal fiber from whole grains is associated with reduced risk of type 2 diabetes and cardiovascular disease. However, there is a lack of evidence from prospective intervention studies targeted to evaluate the potential of dietary fibers to reduce diabetes and cardiovascular disease as recently stated by the Cochrane Foundation. Dietary fiber intake is generally much lower than currently recommended, which may in part be related to side effects of whole grain nutrients and their gustatory properties. Intestinally uncomfortable effects are at least partly related to fermentation which is much less induced by insoluble non-fermentable fibers than by soluble fermentable fibers. The prospective demonstration of beneficial effects of insoluble fibers in preventing diabetes type 2 will allow detailed nutritional recommendations. This may serve to support the consumption of metabolically beneficial constituents of fiber-rich diets and help to increase fiber intake by high fiber natural nutrients or everyday nutrients enriched in insoluble natural fibers.

Ages Eligible for Study:   18 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Impaired glucose tolerance
  • Age>18years old
  • both gender

Exclusion Criteria:

  • Diabetes type 1 and type 2
  • chronic or malignant disease
  • Intake of metabolic influence drugs
  • Food allergies, fiber intolerance
  Contacts and Locations
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Please refer to this study by its ClinicalTrials.gov identifier: NCT01681173

German Instiute of Human Nutrition
Potsdam-Rehbruecke, Nuthetal, Germany, 14558
Charite University
Berlin, Germany, 12200
Sponsors and Collaborators
German Institute of Human Nutrition
Charite University, Berlin, Germany
German Diabetes Foundation, Munich, Germany
Klinikum Ernst von Bergmann Augenklinik Laserzentrum
University Hospital Tuebingen
Principal Investigator: Andreas FH Pfeiffer, Prof. German Institute of Human Nutrition Potsdam-Rehbruecke
  More Information

Responsible Party: Prof. Dr. med. Andreas F. H. Pfeiffer, Chief, Department of Clinical Nutrition, German Institute of Human Nutrition
ClinicalTrials.gov Identifier: NCT01681173     History of Changes
Other Study ID Numbers: DDS-FKZ 232/11/08 
Study First Received: September 5, 2012
Last Updated: February 4, 2015
Health Authority: Germany: Ethics Commission

Keywords provided by German Institute of Human Nutrition:
Nutritional support
Diet therapy
Diabetes prevention
Insoluble fiber
Healthy life style
Weight loss

Additional relevant MeSH terms:
Body Weight
Glucose Metabolism Disorders
Metabolic Diseases
Metabolic Syndrome X
Nutrition Disorders
Insulin Resistance
Pathologic Processes
Signs and Symptoms

ClinicalTrials.gov processed this record on May 25, 2016