OPTIFIT-Optimal Fiber Trial for Diabetes Prevention

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

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.

Study Overview

• Status: Completed
• Conditions: Glucose Metabolism Disorders; Metabolic Diseases; Obesity; Diabetes; Nutrition Disorders; Overweight; Body Weight; Metabolic Syndrome x
• Intervention / Treatment: Dietary supplement: Fiber; Dietary supplement: Placebo

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.

• Study Type: Interventional
• Enrollment (Anticipated): 200
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Germany
  • Berlin, Germany, 12200
    • Charite University
  • Nuthetal
    • Potsdam-Rehbruecke, Nuthetal, Germany, 14558
      • German Instiute of Human Nutrition

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 14 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
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

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change of 2h-postprandial blood glucose from IGT to diabetes mellitus type 2 or normal glucose tolerance (NGT)	Change of the glucose metabolism (OGTT)	0, 12, 24 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change of insulin sensitivity	Measurement by HOMA and OGIS from the OGTT	0, 12, 24 months
Change of insulin secretion	Measurement by the OGTT	0, 12, 24 months
Expression of inflammatory markers in blood	CRP, leukocytes, adipocytokines	0, 6, 12, 18, 24 months
Biometric data	Nutritional impact of blood pressure, anthropometry (body weight and body composition)	0, 6, 12, 18, 24 months
Assessment of cognitive performance		0, 12, 24 months
Development of indices for the prediction of fat mass	Change of fat fraction in liver, abdominal and in the total body fat measuring by MRI/H1-spectroscopy	0, 12, 24 months
Determination of gene expression in adipose tissue	Determination of inflammatory and other transcripts in sc adipose tissue in a fat biopsy.	0, 12, 24 month

Collaborators and Investigators

• Sponsor: German Institute of Human Nutrition
• Collaborators: Charite University, Berlin, Germany; University Hospital Tuebingen; Ernst von Bergmann Hospital; German Diabetes Foundation, Munich, Germany
• Investigators: Principal Investigator: Andreas FH Pfeiffer, Prof., German Institute of Human Nutrition Potsdam-Rehbruecke

Publications and helpful links

General Publications

• Honsek C, Kabisch S, Kemper M, Gerbracht C, Arafat AM, Birkenfeld AL, Dambeck U, Osterhoff MA, Weickert MO, Pfeiffer AFH. Fibre supplementation for the prevention of type 2 diabetes and improvement of glucose metabolism: the randomised controlled Optimal Fibre Trial (OptiFiT). Diabetologia. 2018 Jun;61(6):1295-1305. doi: 10.1007/s00125-018-4582-6. Epub 2018 Feb 28.

Study record dates

Study Major Dates

• Study Start: May 1, 2010
• Primary Completion (Actual): December 1, 2014
• Study Completion (Actual): December 1, 2014

Study Registration Dates

• First Submitted: September 5, 2012
• First Submitted That Met QC Criteria: September 5, 2012
• First Posted (Estimate): September 7, 2012

Study Record Updates

• Last Update Posted (Estimate): February 5, 2015
• Last Update Submitted That Met QC Criteria: February 4, 2015
• Last Verified: February 1, 2015

More Information

Terms related to this study

• Keywords: Weight loss; Nutritional support; Diet therapy; Diabetes prevention; Insoluble fiber; Healthy life style
• Additional Relevant MeSH Terms: Pathologic Processes; Endocrine System Diseases; Insulin Resistance; Hyperinsulinism; Diabetes Mellitus; Disease; Metabolic Syndrome; Overweight; Body Weight; Nutrition Disorders; Metabolic Diseases; Glucose Metabolism Disorders
• Other Study ID Numbers: DDS-FKZ 232/11/08