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Metabolic HealthSIGNATURENCT07255807

Defining the Human Insulin Resistance Molecular Network; SIGNATURE

A study testing Physical Inactivity and Hypercaloric High-Fat Diet in people with Metabolic Health and Insulin Sensitivity/Resistance, run by University of Copenhagen at 1 site in Denmark.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
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Trial summary

The goal of this intervention study is to learn more about what causes insulin resistance in otherwise healthy adults, and how short-term changes in physical activity or diet may influence it. The study includes healthy male and female participants aged 25 to 55 years, who meet specific health criteria. Read more about this study

Who is it for?
Ages 25 to 55 yearsHealthy volunteers can take part
What is being tested?
Physical Inactivity and Hypercaloric High-Fat Diet
Could I receive a placebo?
No, everyone receives an active treatment
How many people
80 participants
Where
1 siteDenmark
Study dates
9 Jan 2026to 30 Jun 2038
Phase
Interventional
Are there results?
Not yet: the study is under way

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 25 to 55 years
  • All sexes
  • Healthy volunteers accepted
  • Adult

Who may be able to join

  • Age: 25-55 years
  • Body Mass Index (BMI): 18-30 kg/m²
  • Healthy (no diagnosed chronic diseases)
  • Able and willing to comply with study procedures

Who cannot join

  • Smoking or nicotine use, current or within the past 5 years
  • Alcohol intake exceeding 10 units per week
  • Hemoglobin A1c (HbA1c) > 48 mmol/mol (indicative of diabetes or prediabetes)
  • Chronic diseases (e.g., cardiovascular disease, diabetes, etc.)
  • Chronic medication use, including hormonal treatments
  • High physical activity levels (more than 3 hours per week of moderate to vigorous exercise)
Show all 10Show fewer
  • Pregnancy or within 3 months postpartum
  • Breastfeeding or within 3 months of cessation
  • Abnormal routine blood markers (as defined in lab screening)
  • Blood donation within the past 2 months

Trial locations and contacts

1 site in 1 country. Contact the study team or a site near you to ask about taking part.

Jørgen F.P. Wojtaszewski, Ph.D. contact

+45 28751625

jw@nexs.ku.dk

Kate A Wickham, Ph.D. contact

+45 30638013

kawi@nexs.ku.dk

Denmark1 site, 1 recruiting
  • August Krogh Building

    Copenhagen, 2100

    Kate A Wickham, Ph.D., +45 30638013, kawi@nexs.ku.dk

    Recruiting

Other trials in Denmark

About this study

Official title: sIgnatuRe: Defining the Human Insulin Resistance Molecular Network

The goal of this intervention study is to learn more about what causes insulin resistance in otherwise healthy adults, and how short-term changes in physical activity or diet may influence it. The study includes healthy male and female participants aged 25 to 55 years, who meet specific health criteria.

The main questions it aims to answer are:

Read more

Does the cause of insulin resistance vary between individuals due to their genes and lifestyle?

Can the investigators identify different types (sub-phenotypes) of insulin resistance at the molecular level?

Researchers will compare groups who either reduce their physical activity for 14 days or consume a high-fat diet for 3 days, to see how these changes affect insulin sensitivity and related biological markers.

Participants will:

  • Complete a health screening and be assessed for eligibility
  • Undergo baseline testing to measure insulin sensitivity, physical activity, diet, and metabolic health
  • Be randomly assigned to one of two short-term interventions (14 days of reduced physical activity, or 3 days of a high-fat, high-calorie diet)
  • Repeat selected tests after the intervention to assess changes

This study will help researchers better understand how lifestyle and biology interact in the development of insulin resistance, even in people who are otherwise healthy.

Read the detailed description

This intervention study aims to uncover the molecular mechanisms that underlie insulin resistance in otherwise healthy adults and to explore how short-term lifestyle changes may influence these mechanisms. Insulin resistance is a key feature in the development of type 2 diabetes and other metabolic diseases, but it does not arise uniformly across individuals. The overarching hypothesis is that insulin resistance has multiple underlying causes that differ between individuals, depending on genetic variation and modifiable lifestyle factors such as physical activity and diet.

A total of 80 healthy participants-40 males and 40 females aged between 25 and 55 years-will be recruited. All participants must have a body mass index (BMI) between 18 and 30 and meet strict inclusion and exclusion criteria to minimize confounding variables. Participants will be free of chronic disease, non-smokers, have limited alcohol intake, and not engage in high levels of physical activity. This controlled approach ensures a more accurate assessment of the variables under investigation.

At baseline, all participants will undergo comprehensive phenotyping, including assessments of habitual physical activity, dietary intake, glucose tolerance, and whole-body insulin sensitivity. This will allow the researchers to categorize sub-phenotypes of insulin resistance at both the physiological and molecular level.

Following baseline testing, 40 of the 80 participants will undergo one of two short-term interventions designed to stress metabolic pathways associated with insulin sensitivity:

  • Reduced physical activity: Participants will significantly decrease their daily physical activity for 14 days.
  • High-fat diet: Participants will consume a hypercaloric high-fat diet for 3 consecutive days.

The aim of these interventions is to test how short-term negative lifestyle changes impact insulin action and related molecular markers, and whether these responses vary between individuals with different phenotypic and genetic profiles.

After the intervention period, selected metabolic tests will be repeated to assess changes in insulin sensitivity and molecular signaling. The primary outcome measure is whole-body insulin action, assessed using gold-standard physiological methods. Exploratory outcomes include identifying cellular and molecular mechanisms contributing to insulin resistance, and understanding the interaction between gene expression and lifestyle responses.

By combining deep phenotyping with short-term interventions, this study will generate new insights into the biological diversity of insulin resistance. Ultimately, this may contribute to the development of more individualized strategies for the prevention and treatment of metabolic diseases.

Being tested
Physical Inactivity, Hypercaloric High-Fat Diet
Keywords
Insulin Resistance, Metabolic Health, Glucose Metabolism, Lifestyle Interventions, Physical Inactivity, High-Fat Diet, Molecular Mechanisms, Insulin Sensitivity, Metabolic Phenotyping, Human Intervention Study
Medical subject headings
Insulin Resistance, Sedentary Behavior

What participants receive

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

  • Physical InactivityBehavioural

    Also called Reduced Activity

    Participants assigned to the physical inactivity intervention will reduce their daily physical activity to fewer than 1,500 steps per day for 14 consecutive days. This strict limitation significantly decreases overall movement and muscle activity, mimicking a sedentary lifestyle. The aim is to assess the short-term effects of reduced physical activity on insulin sensitivity and related metabolic processes. Compliance will be monitored using activity trackers and daily logs. Baseline metabolic and physiological assessments will be repeated after the intervention to evaluate changes.

  • Hypercaloric High-Fat DietBehavioural

    Also called Overeating

    Participants assigned to the high-fat diet intervention will consume a hypercaloric diet rich in fat for 3 consecutive days. The diet is designed to significantly increase caloric intake and fat consumption beyond habitual levels to induce short-term metabolic stress. This intervention aims to assess how a brief period of high-fat overfeeding affects insulin sensitivity and related molecular pathways. Participants' dietary intake will be carefully controlled and monitored to ensure adherence. Baseline metabolic and physiological assessments will be repeated after the intervention to evaluate changes.

Study groups in NCT07255807
Study groupRoleWhat they receive
Baseline CharacterizationNo interventionAll participants (N=80) undergo extensive baseline characterization over three study visits. This includes assessments of insulin sensitivity, glucose tolerance, metabolic and physiological phenotyping, habitual physical activity, and dietary intake. No intervention is applied during this phase; the purpose is to establish baseline measures and characterize individual variation in insulin resistance and metabolic profiles. Participants complete detailed clinical, physiological, and behavioral assessments without any experimental manipulation. This includes: * Measurement of insulin action and glucose tolerance * Dietary and physical activity profiling * Collection of biospecimens for molecular analyses
Lifestyle InterventionsExperimentalA subset of 40 participants are randomized into one of two experimental interventions following baseline assessment: * 14 days of reduced physical activity (<1,500 steps/day), or * 3 days of a hypercaloric high-fat diet The aim is to evaluate how short-term lifestyle stressors affect insulin sensitivity and related molecular markers. Assessments from visits 4 and 5 are compared to baseline to determine within-subject changes. Intervention Names: 1. Reduced Physical Activity - Participants limit daily steps to <1,500 for 14 days 2. High-Fat Diet * Participants consume a hypercaloric, high-fat diet for 3 days Description of Intervention: Participants undergo one of the two lifestyle interventions with strict monitoring and support. Selected baseline tests are repeated post-intervention to evaluate metabolic and molecular responses.
Receives: Behavioral: Physical Inactivity; Behavioral: Hypercaloric High-Fat Diet

What is being measured

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

  1. Whole-body insulin action

    Glucose disposal rates during hyperinsulinemic euglycemic conditions as a marker of whole-body insulin action

    Measured: Baseline characterization & immediately following intervention (either 14 days of physical inactivity or 3 days of hypercaloric high-fat diet)

Secondary outcomes (3)
  1. Identification of proteins and posttranslational modification of proteins in blood as well as skeletal muscle and adipose tissue biopsies

    The obtained samples will be subjected to mass spectrometry-based proteomic and phosphoproteomic analyses. These measurements show protein abundance and posttranslational modifications that regulates protein function. Ultimately, revealing the signaling network underlying the interventions studied. Unit of measure is log2-transformed arbitrary units.

    Measured: Baseline & immediately following the intervention (14 days of physical inactivity or 3 days of hypercaloric high-fat diet)

  2. Whole-Body Glucose Tolerance

    Whole-body glucose tolerance will be assessed by an oral glucose tolerance test (OGTT). Blood glucose and insulin concentrations will be measured at multiple time points following oral glucose ingestion to determine glucose and insulin responses. Glucose and insulin areas under the curve (AUC) values will be used to evaluate changes in glucose tolerance.

    Measured: Baseline

  3. Beta Cell Function

    Beta cell function will be evaluated using an intravenous glucose tolerance test (IVGTT). Following intravenous glucose administration, arterial glucose and insulin concentrations will be measured at multiple time points to assess first-phase insulin secretion and beta cell responsiveness.

    Measured: Baseline & immediately following the intervention (14 days of physical inactivity or 3 days of hypercaloric high-fat diet)

Timeline

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

  1. First posted1 Dec 2025
  2. Study start9 Jan 2026
  3. Primary completion30 Jun 2028 (estimated)
  4. Study completion30 Jun 2038 (estimated)

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
Basic science
Allocation
Randomised
Intervention model
Parallel groups
Model description
This study uses a parallel design involving 80 healthy participants who all undergo comprehensive baseline assessments, including physiological and metabolic phenotyping, habitual physical activity, and dietary intake evaluations. Following baseline characterization, 40 participants are assigned to one of two independent intervention arms: 14 days of reduced physical activity or 3 days of a hypercaloric high-fat diet. Each intervention group is studied in parallel, with outcomes compared to assess the specific effects on insulin sensitivity and molecular mechanisms. The parallel design was chosen due to the invasive and time-intensive nature of the interventions and testing procedures, making a crossover design impractical and burdensome for participants.
Masking
None (open label)
Enrolment
80 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07255807
Sponsor's protocol ID
SIGNATURE
Other IDs
NNF24OC0085866
Acronym
SIGNATURE
Status last verified
Nov 2025
First submitted
6 Aug 2025
Last updated
17 Aug 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No: Due to the sensitive nature of the physiological and molecular data collected, and the relatively small and deeply phenotyped cohort, there is a risk of re-identification. Participants have not provided explicit consent for public sharing of their individual data. Furthermore, data protection regulations under the EU General Data Protection Regulation (GDPR) place strict limitations on the sharing of personal data, particularly when it concerns health-related information. For these reasons, individual participant data will not be shared publicly. Data sharing may be considered in the future under controlled access with appropriate ethical approvals and data use agreements.

Questions about this trial

What is this clinical trial studying?

A study testing Physical Inactivity and Hypercaloric High-Fat Diet in people with Metabolic Health and Insulin Sensitivity/Resistance, run by University of Copenhagen at 1 site in Denmark.

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 4 inclusion and 10 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: looking for participants now, as of the sponsor's last update on 17 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Denmark. 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?

This study is still under way. Results are not available in the source record yet.

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

Contact Jørgen F.P. Wojtaszewski, Ph.D. (+45 28751625, jw@nexs.ku.dk), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Whole-body insulin action (time frame: Baseline characterization & immediately following intervention (either 14 days of physical inactivity or 3 days of hypercaloric high-fat diet)). It is what the study was designed to measure, not a finding.

Where can I read the original study information?
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 17 Aug 2026.

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