Clinical trial NCT00579657: Protein, Fiber, and Metabolic Syndrome - The PROFIMET Study
Official title: Effects of High Protein and High Cereal Fiber Diets on Insulin Sensitivity in Overweight and Obese Subjects With the Metabolic Syndrome - The PROFIMET Study
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Overweight
Obesity
Metabolic Syndrome
Keywords: parameters of metabolic syndrome
Lead sponsor: German Institute of Human Nutrition
Sponsor class: OTHER
Collaborators: name: German Federal Ministry of Education and Research
name: Medical University of Vienna
name: Heinrich-Heine University, Duesseldorf
name: University Hospital Tuebingen
name: Charite University, Berlin, Germany
name: University Hospitals Coventry and Warwickshire NHS Trust
name: Coventry University
First posted: 2007-12-24
Enrollment: 111
Sex: ALL
Minimum age (years): 24
Maximum age (years): 70
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: BASIC_SCIENCE

Brief summary: Randomized controlled single-blinded intervention study in 111 overweight and obese subjects with risk factors of developing type 2 diabetes, with the aim to investigate effects of isoenergetic high cereal fiber as compared with high protein diets over 6 and 18 weeks.

Proof of principle study with analysis according to study protocol, investigating whether isoenergetic high cereal fiber and high protein diets with comparable fat contents, if adhered to and after exclusion of known confounders such as changes in body weight, intake of drugs with known effects on insulin sensitivity, or relevant changes in physical activity, indeed affect insulin sensitivity.

Detailed description: This is a randomized controlled single-blinded intervention study in 111 overweight and obese subjects with risk factors of developing type 2 diabetes, with the aim to investigate effects of isoenergetic high cereal fiber versus high protein diets over 6 and 18 weeks. We also investigate effects of a combined high-cereal-fiber/high-protein (mix) diet, and effects in a control group. All diets are based on foods from plants and whey products commonly assumed to be healthy. This trial is designed as a proof of principle study focusing on participants that are likely to adhere to the respective isoenergetic diets, in order to show whether high protein versus high cereal fiber diets indeed affect insulin sensitivity, as indicated by epidemiological observations. Study participants will receive intensive and regular nutritional advice in order to achieve the respective dietary targets. Dietary adherence of the participants will be supported by providing tailored dietary supplements in all four groups, twice daily over 18 weeks. Supplements are provided for twice daily consumption for all participants in all four dietary intervention groups, throughout the 18-wk intervention (each of the participants will be instructed to consume a total 252 portions of tailored supplements during the intervention, which will handed to the participants in sealed single portions at weeks 0, 3, 6 and 12, totalling 63 portions at each occasion). The packaging of the sealed portions for the 4 intervention arms do not indicate the type of dietary intervention for the participant, but are coded for identification by the supplier. Energy contents of the supplements are considered when calculating individual energy intake. Supplements have been specifically designed for this intervention study, in order to facilitate achieving dietary targets. A 6 week strictly controlled isoenergetic study period (regular group and individual sessions, daily food diaries/FFQs over the first 6 weeks with adaptation of food intake, if necessary, as indicated by direct analysis of FFQs and food protocols, and by weighing the participants; 3-day food protocols at weeks 0, 6, 12, and 18; various biomarkers of dietary adherence) will be followed by a further 12 week ad libitum period, with ongoing intake of the respective diet including the supplements, but no further dietary advice. The primary outcome measure is the detection of diet-induced changes in insulin sensitivity during weight maintaining isoenergetic conditions. Secondary outcomes are changes in factors that may explain potential diet-induced alterations of insulin sensitivity. During the 12-weeks ad libitum period we will further investigate potential effects of the respective diet on changes in body weight, body composition and biomarkers related to energy intake. Participants will be re-invited for anthropometric measurements and measurement of biomarkers in blood (18 weeks after completion of the study), as well as for taking a second muscle tissue biopsy (subset of participants that agreed to this procedure).

Eligibility criteria: Inclusion Criteria:

* Waist \> 80 cm (females) or \> 94 cm (males)
* BMI \> 25 kg/m²
* IFG, IGT, or insulin resistance; and/or dyslipidemia; and/or high blood pressure
* Willingness to comply with one of the randomly assigned diets over the study period

Exclusion Criteria:

* Diabetes type 1 and type 2
* Pregnancy
* Allergies including food allergies
* Metal implants
* Chronic disease of heart, kidney, or liver
* Relevant deviation of body weight during isoenergetic 6-weeks period (+/- 3 kg)
* Intake of drugs with known impact on whole-body insulin sensitivity during the study (e.g. cortisone, ASS, antibiotics)
* Missing data about primary outcome measures (Clamp data, data about dietary intake from food diaries or 3-day food protocols)
* Significant deviation from dietary targets during the monitored 6 weeks isoenergetic period (e.g. significant deviation from 30% target for dietary fat in all groups, intake of a low protein or low fiber diet in the high protein or high fiber groups, respectively)

Primary outcomes:
measure: change in insulin sensitivity
timeFrame: 6 weeks
measure: change in insulin sensitivity
timeFrame: 18 weeks
Secondary outcomes:
measure: factors that may contribute explaining changes in primary outcome measures
timeFrame: 0, 6, 18 weeks
measure: biomarkers indicating dietary adherence
timeFrame: 0, 6, 18 weeks
measure: development of indices for the prediction of insulin resistance (liver, whole-body)
timeFrame: baseline, validation after 6 -18 weeks
measure: development for indices for the prediction of fat mass (liver, abdominal)
timeFrame: baseline, validation after 6 -18 weeks
Other outcomes:
Locations:
city: Düsseldorf
country: Germany
facility: Deutsches Diabetes Zentrum; Heinrich Heine University
city: Potsdam
country: Germany
facility: Diagnostic and Interventional Radiology, Klinikum Ernst von Bergmann, Academic Teaching Hospital, Charité University Medicine Berlin
city: Tübingen
country: Germany
facility: Eberhard-Karls University Tübingen, Section on Experimental Radiology, Department of Diagnostic and Interventional Radiology
city: Coventry
country: United Kingdom
facility: University Hospitals Coventry and Warwickshire NHS Trust
state: Warwickshire
Study officials:
affiliation: University Hospitals Coventry & Warwickshire; and University of Warwick, UK
name: Martin O Weickert, MD
role: STUDY_CHAIR
affiliation: German Institute of Human Nutrition Potsdam-Rehbrücke; Charité-University-Medicine Berlin
name: Andreas FH Pfeiffer, Prof
role: STUDY_DIRECTOR
References:
citation: Gogebakan O, Kohl A, Osterhoff MA, van Baak MA, Jebb SA, Papadaki A, Martinez JA, Handjieva-Darlenska T, Hlavaty P, Weickert MO, Holst C, Saris WH, Astrup A, Pfeiffer AF; DiOGenes. Effects of weight loss and long-term weight maintenance with diets varying in protein and glycemic index on cardiovascular risk factors: the diet, obesity, and genes (DiOGenes) study: a randomized, controlled trial. Circulation. 2011 Dec 20;124(25):2829-38. doi: 10.1161/CIRCULATIONAHA.111.033274. Epub 2011 Nov 21.
citation: Isken F, Klaus S, Osterhoff M, Pfeiffer AF, Weickert MO. Effects of long-term soluble vs. insoluble dietary fiber intake on high-fat diet-induced obesity in C57BL/6J mice. J Nutr Biochem. 2010 Apr;21(4):278-84. doi: 10.1016/j.jnutbio.2008.12.012. Epub 2009 Apr 14.
citation: Weickert MO, Pfeiffer AF. Low-glycemic index vs high-cereal fiber diet in type 2 diabetes. JAMA. 2009 Apr 15;301(15):1538; author reply 1538-9. doi: 10.1001/jama.2009.483. No abstract available.
citation: Weickert MO, Pfeiffer AF. Metabolic effects of dietary fiber consumption and prevention of diabetes. J Nutr. 2008 Mar;138(3):439-42. doi: 10.1093/jn/138.3.439.
citation: Weickert MO, Mohlig M, Schofl C, Arafat AM, Otto B, Viehoff H, Koebnick C, Kohl A, Spranger J, Pfeiffer AF. Cereal fiber improves whole-body insulin sensitivity in overweight and obese women. Diabetes Care. 2006 Apr;29(4):775-80. doi: 10.2337/diacare.29.04.06.dc05-2374.
citation: Weickert MO, Mohlig M, Koebnick C, Holst JJ, Namsolleck P, Ristow M, Osterhoff M, Rochlitz H, Rudovich N, Spranger J, Pfeiffer AF. Impact of cereal fibre on glucose-regulating factors. Diabetologia. 2005 Nov;48(11):2343-53. doi: 10.1007/s00125-005-1941-x. Epub 2005 Sep 20.
citation: Weickert MO, Roden M, Isken F, Hoffmann D, Nowotny P, Osterhoff M, Blaut M, Alpert C, Gogebakan O, Bumke-Vogt C, Mueller F, Machann J, Barber TM, Petzke KJ, Hierholzer J, Hornemann S, Kruse M, Illner AK, Kohl A, Loeffelholz CV, Arafat AM, Mohlig M, Pfeiffer AF. Effects of supplemented isoenergetic diets differing in cereal fiber and protein content on insulin sensitivity in overweight humans. Am J Clin Nutr. 2011 Aug;94(2):459-71. doi: 10.3945/ajcn.110.004374. Epub 2011 Jun 1.
citation: Weickert MO, Arafat AM, Blaut M, Alpert C, Becker N, Leupelt V, Rudovich N, Mohlig M, Pfeiffer AF. Changes in dominant groups of the gut microbiota do not explain cereal-fiber induced improvement of whole-body insulin sensitivity. Nutr Metab (Lond). 2011 Dec 17;8:90. doi: 10.1186/1743-7075-8-90.
citation: Hattersley JG, Mohlig M, Roden M, Arafat AM, Loeffelholz CV, Nowotny P, Machann J, Hierholzer J, Osterhoff M, Khan M, Pfeiffer AF, Weickert MO. Quantifying the improvement of surrogate indices of hepatic insulin resistance using complex measurement techniques. PLoS One. 2012;7(6):e39029. doi: 10.1371/journal.pone.0039029. Epub 2012 Jun 22.
citation: Weickert MO. What dietary modification best improves insulin sensitivity and why? Clin Endocrinol (Oxf). 2012 Oct;77(4):508-12. doi: 10.1111/j.1365-2265.2012.04450.x.
citation: Hattersley JG, Pfeiffer AF, Roden M, Petzke KJ, Hoffmann D, Rudovich NN, Randeva HS, Vatish M, Osterhoff M, Goegebakan O, Hornemann S, Nowotny P, Machann J, Hierholzer J, von Loeffelholz C, Mohlig M, Arafat AM, Weickert MO. Modulation of amino acid metabolic signatures by supplemented isoenergetic diets differing in protein and cereal fiber content. J Clin Endocrinol Metab. 2014 Dec;99(12):E2599-609. doi: 10.1210/jc.2014-2302.
citation: Cuthbertson DJ, Weickert MO, Lythgoe D, Sprung VS, Dobson R, Shoajee-Moradie F, Umpleby M, Pfeiffer AF, Thomas EL, Bell JD, Jones H, Kemp GJ. External validation of the fatty liver index and lipid accumulation product indices, using 1H-magnetic resonance spectroscopy, to identify hepatic steatosis in healthy controls and obese, insulin-resistant individuals. Eur J Endocrinol. 2014 Nov;171(5):561-9. doi: 10.1530/EJE-14-0112.