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Diabetes Mellitus, Type 2NCT05375656

The Effect on Metabolism, Food Intake and Preferences of a Knockout Gene Variant Involved in Carbohydrate Metabolism

A study testing Cross-over study in people with Diabetes Mellitus, Type 2 and Metabolic Disease, run by Steno Diabetes Center Copenhagen at 2 sites in Greenland.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

Around 10% has type 2 diabetes in Greenland, despite being a practically unknown disease only six decades ago. The drastic increase is of great concern, especially considering the transition that have occurred during the same decades going from a fisher-hunter lifestyle towards a more western lifestyle. Read more about this study

Who is it for?
Ages 18 to 80 years
What is being tested?
Cross-over study
Could I receive a placebo?
No, everyone receives an active treatment
How many people
38 participants
Where
2 sitesGreenland
Study dates
8 Jan 2022to 7 May 2022
Phase
Interventional
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 80 years
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Homozygous carriers of the c.273_274delAG variant in the SI-gene (cases)
  • Homozygous non-carriers of the c.273_274delAG variant in the SI-gene (controls)

Who cannot join

  • Diagnosis of diabetes or pharmacological treatment of diabetes.
  • Gastrointestinal diseases such as inflammatory bowel disease, gastrointestinal cancer, and ulcer. Persons with mild gastrointestinal problems are not excluded, e.g. persons with lactose-intolerance who normally do not have any gastrointestinal problems.
  • Homozygous carriers of the TBC1D4 risk variant p.Arg684Ter.
  • Lack of compliance with the procedures in the study protocol, judged by Investigator.
  • For the homozygous carriers of the c.273_274delAG variant: rise in blood glucose in an oral sucrose tolerance test.

Trial locations and contacts

2 sites in 1 country.

Greenland2 sites
  • Maniitsoq Healthcare Center

    Maniitsoq

  • Pikialaarfik, Greenland Institute of Natural Resources

    Nuussuaq, 3905

About this study

Around 10% has type 2 diabetes in Greenland, despite being a practically unknown disease only six decades ago. The drastic increase is of great concern, especially considering the transition that have occurred during the same decades going from a fisher-hunter lifestyle towards a more western lifestyle. Today, traditional marine foods are still increasingly being replaced by imported foods high in refined sugar (sucrose) and starch. Furthermore, recent studies discovered that the Greenlandic population harbors a different genetic architecture behind type 2 diabetes. Hence, obtaining more knowledge on interactions between lifestyle, genetics, and metabolism is therefore crucial in order to ameliorate the growing curve, or maybe even turn it around.

Sucrose intolerance is in general rare; however, it is a common condition in Greenland and other Inuit populations. Here it is caused by a genetic variant in the sucrase-isomaltase (SI) gene, resulting in complete loss of enzyme function and hence an inability to digest sucrose and some of the glycosidic bonds in starch, both carbohydrates that are not part of the traditional Inuit diet. A recent, unpublished study found the variant to be associated with lower BMI, body fat percentage, bodyweight, and lipid levels independent of the lower intake of refined sugar. This might be explained by differences in the metabolism of carbohydrates and in the gut microbiota. The healthier phenotype was confirmed by a SI knockout mouse model, which furthermore interestingly indicated that the variant might alter food and taste preferences.

It is anticipated that the drastic increase in type 2 diabetes in Greenland can be explained at least partly by the complex interaction between lifestyle and genetics. Therefore, the aim is to investigate if metabolic and microbial differences can explain the healthier phenotype of the homozygous carriers of the SI variant than wildtype individuals amd perform a 3-day cross-over dietary intervention using assigning subjects to a traditional Greenlandic diet and a Western diet. Moreover, the aim is to assess whether their food and taste preferences are different. The study will help us to understand the complex interactions between lifestyle, behavior, genetics, the microbiota and the host metabolism.

Read the detailed description

In this human study, effects of the SI knockout variant on metabolism, dietary habits and food preferences will be quantified. The study will be unique by being the first assessing the effect of a complete loss of SI function, which it is only feasible in Arctic populations.

Differences between homozygous (HO) carriers and heterozygous (HE)/wildtype (WT) individuals are suspected to be large on a carbohydrate-rich diet and small on a traditional diet. The following hypotheses will be addressed:

HO carriers metabolize carbohydrates differently than HE+WT individuals:

  1. HO have a lower glycemic variability on their habitual diet than WT+HE.
  2. HO have a lower glycemic variability on a starch and sucrose rich diet than WT+HE.
  3. HO have a glycemic variability similar to WT+HE on a traditional diet low in carbohydrates. HO carriers have different food preferences than HE+WT individuals:
  4. HO have a lower sweet taste preference compared to WT+HE.
  5. HO perceive iso-intense solutions of sucrose, fructose, and glucose differently in sweet taste intensity and WT+HE will perceive them iso-intense.
  6. HO consume less high-sugar-low-fat foods than WT+HE.
  7. HO have similar intake and preference for high-sugar-high-fat foods as WT+HE. HO carriers have a microbiota different from HE+WT individuals:
  8. Diversity and abundance of starch-fermenting bacteria is higher in HO than in WT+HE and the abundance of Parabacteroides is lower.
  9. The increase in starch-fermenting bacteria as well as fecal and circulating levels of short chain fatty acids is larger for HO than in WT+HE on a starch and sucrose rich diet.
  10. A diet low in carbohydrates will alter the microbiota similarly for HO and WT+HE.
Being tested
Cross-over study
Keywords
Inuit, Greenlandic diet, Diabetes, Microbiota, Glucose variability, Food preference, SI
Medical subject headings
Diabetes Mellitus, Type 2, Metabolic Diseases, Sucrase-isomaltase deficiency, congenital, Diabetes Mellitus, Food Preferences

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Cross-over studyOther

    Traditional Inuit Diet and Western Diet.

Study groups in NCT05375656
Study groupRoleWhat they receive
Traditional Inuit DietActive comparatorThe traditional Inuit diet will consist of local foods, being primarily of animal origin, e.g. fish, marine mammals, caribou, and lamb. The diet will be supplemented with eggs, potatoes, and berries, and/or other foods low in starch and with no sucrose content. The diet will therefore have a high content of fat and protein, a low content of carbohydrate and no content of sucrose. The participants will receive foods that will cover at least 100% of their energy requitement. Each participant will throw a dice in order to randomize the order of which the participants receive the two intervention diets.
Receives: Other: Cross-over study
Western Carbohydrate-Rich DietExperimentalThe Western diet will have high amounts of grain products, e.g. bread, pasta, rice, as well as fruits and vegetables and some foods with a high sucrose content, e.g. cake and sweet snacks and/or drinks, and cereal products with added sucrose. The diet will have a low amount of meat. Hence, the diet will be high in carbohydrates, starch, and some sucrose and have a lower content of protein and fat. The participants will receive foods that will cover at least 100% of their energy requitement. Each participant will throw a dice in order to randomize the order of which the participants receive the two intervention diets.
Receives: Other: Cross-over study

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Glycemic variability during Western diet

    Glycemic variability will be measured by mean amplitude of glycemic excursions (MAGE) during the whole study period, i.e. during both Western and Inuit diet and the wash-out period in between.

    Measured: During the 3 days of intervention with Western diet.

  2. Glycemic variability during Inuit diet

    Glycemic variability will be measured by mean amplitude of glycemic excursions (MAGE) during the whole study period, i.e. during both Western and Inuit diet and the wash-out period in between.

    Measured: During the 3 days of intervention with Inuit diet.

Secondary outcomes (30)
  1. Sweet Bias Score

    As a food reward measure, explicit liking for foods with sweet relative to savory taste will be assessed using the Leeds Food Preference Questionnaire. A sweet bias score will be estimated, where a positive score indicates higher preference for sweet relative to savoury foods and a negative score indicates higher preference for savoury foods.

    Measured: Baseline (to assess differences between genotypes, independent of the intervention)

  2. Fat Bias Score

    As a food reward measure, explicit liking for foods with high-fat relative to low-fat content will be assessed using the Leeds Food Preference Questionnaire. A fat bias score will be estimated, where a positive score indicates higher preference for high-fat relative to low-fat foods and a negative score indicates higher preference for low-fat foods.

    Measured: Baseline (to assess differences between genotypes, independent of the intervention)

  3. High-fat savory preference

    As a food reward measure, explicit liking for high-fat savory foods will be assessed in the Leeds Food Preference Questionnaire. The average rating from 0-100 on the visual analogue scale is calculated for all four foods within the food category.

    Measured: Baseline (to assess differences between genotypes, independent of the intervention)

  4. Low-fat savory preference

    As a food reward measure, explicit liking for low-fat savory foods will be assessed in the Leeds Food Preference Questionnaire. The average rating from 0-100 on the visual analogue scale is calculated for all four foods within the food category.

    Measured: Baseline (to assess differences between genotypes, independent of the intervention)

  5. High-fat sweet preference

    As a food reward measure, explicit liking for high-fat sweet foods will be assessed in the Leeds Food Preference Questionnaire. The average rating from 0-100 on the visual analogue scale is calculated for all four foods within the food category.

    Measured: Baseline (to assess differences between genotypes, independent of the intervention)

  6. Low-fat sweet preference

    As a food reward measure, explicit liking for low-fat sweet foods will be assessed in the Leeds Food Preference Questionnaire. The average rating from 0-100 on the visual analogue scale is calculated for all four foods within the food category.

    Measured: Baseline (to assess differences between genotypes, independent of the intervention)

  7. Implicit wanting score: High-fat savory foods

    As a food reward measure, implicit wanting for high-fat savory foods will be assessed using the Leeds Food Preference Questionnaire.

    The 'implicit wanting' score is calculated based on a combination of reaction time and choice or non-choice of foods in the forced choice paradigm. A positive score indicates a higher preference for this food category compared to the other food categories, and a negative score indicates a lower preference for this food category.

    Measured: Baseline (to assess differences between genotypes, independent of the intervention)

  8. Implicit wanting score: Low-fat savory foods

    As a food reward measure, implicit wanting for low-fat savory foods will be assessed using the Leeds Food Preference Questionnaire.

    The 'implicit wanting' score is calculated based on a combination of reaction time and choice or non-choice of foods in the forced choice paradigm. A positive score indicates a higher preference for this food category compared to the other food categories, and a negative score indicates a lower preference for this food category.

    Measured: Baseline (to assess differences between genotypes, independent of the intervention)

  9. Implicit wanting score: High-fat sweet foods

    As a food reward measure, implicit wanting for high-fat sweet foods will be assessed using the Leeds Food Preference Questionnaire.

    The 'implicit wanting' score is calculated based on a combination of reaction time and choice or non-choice of foods in the forced choice paradigm. A positive score indicates a higher preference for this food category compared to the other food categories, and a negative score indicates a lower preference for this food category.

    Measured: Baseline (to assess differences between genotypes, independent of the intervention)

  10. Implicit wanting score: Low-fat sweet foods

    As a food reward measure, implicit wanting for low-fat sweet foods will be assessed using the Leeds Food Preference Questionnaire.

    The 'implicit wanting' score is calculated based on a combination of reaction time and choice or non-choice of foods in the forced choice paradigm. A positive score indicates a higher preference for this food category compared to the other food categories, and a negative score indicates a lower preference for this food category.

    Measured: Baseline (to assess differences between genotypes, independent of the intervention)

  11. Habitual diet

    Habitual dietary intake will be assessed using a food frequency questionnaire. Macronutrient composition and content of sugar will be assessed as well as characterization of differences in food choice with respect to sweet foods and foods rich in starch. Intake will be expressed in g/day as well as E%.

    Measured: Baseline (to assess differences between genotypes, independent of the intervention)

  12. Intake in a snacking test meal

    Using an ad libitum snacking test meal, preferences will be assessed for sweet-taste and content of sucrose and fat as well as other sweeteners than sucrose, e.g. honey.

    Measured: Baseline (to assess differences between genotypes, independent of the intervention)

  13. Sucrose sweetness sensitivity

    Ability to taste a difference between iso-intense solutions of sucrose and fructose+glucose using a 2-alternative forced choice test

    Measured: Baseline (to assess differences between genotypes, independent of the intervention)

  14. Sweet liking

    Hedonic rating of liking of iso-intense solutions of sucrose, fructose, glucose and fructose+glucose using a visual analogue scale (0-100 mm)

    Measured: Baseline (to assess differences between genotypes, independent of the intervention)

  15. Perceived intensity of sugars

    Hedonic rating of perceived intensity of iso-intense solutions of sucrose, fructose, glucose and fructose+glucos using a visual analogue scale (0-100 mm)

    Measured: Baseline (to assess differences between genotypes, independent of the intervention)

  16. Plasma lipids

    Changes in fasting plasma measures of VLDL-cholesterol, LDL-cholesterol, HDL-cholesterol, total cholesterol, remnant cholesterol, and triglycerides

    Measured: The day before and the day after each dietary intervention period.

  17. Serum insulin

    Changes in serum insulin. Fasting sample.

    Measured: The day before and the day after each dietary intervention period.

  18. Plasma CRP

    Changes in plasma CRP. Fasting sample.

    Measured: The day before and the day after each dietary intervention period.

  19. Plasma acetate

    Changes in plasma acetate. Fasting sample.

    Measured: The day before and the day after each dietary intervention period.

  20. Plasma propionate

    Changes in plasma propionate. Fasting sample.

    Measured: The day before and the day after each dietary intervention period.

  21. Plasma butyrate

    Changes in plasma butyrate. Fasting sample.

    Measured: The day before and the day after each dietary intervention period.

  22. HbA1c

    Fasting glycated hemoglobin

    Measured: Baseline

  23. Fecal acetate

    Changes in fecal acetate.

    Measured: Before and on the last day or on the day after each dietary intervention period.

  24. Fecal propionate

    Changes in fecal propionate.

    Measured: Before and on the last day or on the day after each dietary intervention period.

  25. Fecal butyrate

    Changes in fecal butyrate.

    Measured: Before and on the last day or on the day after each dietary intervention period.

  26. Fecal pH

    pH of fecal samples.

    Measured: Before and on the last day or on the day after each dietary intervention period.

  27. Changes in gut microbiota composition

    Changes in gut microbiota composition between baseline and end of each dietary intervention period. Microbiota composition is measured by genome sequencing fecal samples.

    Measured: Before and on the last day or on the day after each dietary intervention period.

  28. Baseline gut microbiota composition

    Characterization of the gut microbiota composition. Microbiota composition is measured by genome sequencing fecal samples.

    Measured: Before intervention (baseline).

  29. Fecal carbohydrates

    Content of carbohydrates in fecal samples and changes in this during the intervention periods.

    Measured: Before and on the last day or on the day after each dietary intervention period.

  30. Glycemic variability during habitual diet

    Glycemic variability will be measured by mean amplitude of glycemic excursions (MAGE)

    Measured: Measured during 7 days of wash-out

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted17 May 2022
  2. Study start8 Jan 2022
  3. Primary completion7 May 2022
  4. Study completion7 May 2022

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Prevention
Allocation
Randomised
Intervention model
Crossover
Model description
A cross-over design will be applied to the intervention. Participants will be randomized to first receive either a diet high in starch and relatively high in sucrose, resembling a western diet, or a diet low in carbohydrate with many marine foods, resembling a traditional Inuit diet. There will be a wash out period of 7 days between the two diets. Each participant will throw a dice in order to randomize the order of which the participants receive the two intervention diets.
Masking
Triple blind
Who is masked
Participant, Care provider, Outcomes assessor
Enrolment
38 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05375656
Sponsor's protocol ID
F15319-03
Status last verified
May 2022
First submitted
27 Sep 2021
Last updated
31 May 2022
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Publications

  • Senftleber N, Christensen MMB, Carstensen B, Staeger FF, Frost MB, Gillum MP, Hansen T, Jorgensen ME. Dietary effect on glucose homeostasis is modulated by a loss-of-function variant in the sucrase-isomaltase gene: a randomised, dietary crossover intervention in Inuit. Diabetologia. 2026 Jul;69(7):2015-2028. doi: 10.1007/s00125-026-06723-4. Epub 2026 Apr 17.

    PubMed 41995844
  • Senftleber NK, Skott Pedersen K, Schnoor Jorgensen C, Pedersen H, Bjerg Christensen MM, Kabel Madsen E, Andersen K, Jorsboe E, Gillum MP, Frost MB, Hansen T, Jorgensen ME. The effect of sucrase-isomaltase deficiency on metabolism, food intake and preferences: protocol for a dietary intervention study. Int J Circumpolar Health. 2023 Dec;82(1):2178067. doi: 10.1080/22423982.2023.2178067. Epub 2023 Feb 22.

    PubMed 38113483

Questions about this trial

What is this clinical trial studying?

A study testing Cross-over study in people with Diabetes Mellitus, Type 2 and Metabolic Disease, run by Steno Diabetes Center Copenhagen at 2 sites in Greenland.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 2 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 31 May 2022. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 2 sites in Greenland. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Glycemic variability during Western diet (time frame: During the 3 days of intervention with Western diet.). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT05375656, which also lists 2 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 31 May 2022.

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