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Enrolling by Invitation

NCT Number: NCT07566845

Women With Previous GDM and the Effects of HIIT.

The goal of this clinical trial is to investigate if women with previous gestational diabetes (pGDM) are characterized with unique metabolic and molecular alterations compared to women without pGDM. Furthermore if 8 weeks of high-intensity interval training (HIIT) can improve these alterations. The main questions we aim to answer are:

1. Women with pGDM have metabolic abnormalities compared with women without pGDM, and that these metabolic abnormalities are explained by unique molecular abnormalities in skeletal muscle and adipose tissue. 2. Eight weeks of HIIT combining rowing and cycling can markedly improve these metabolic abnormalities in women with pGDM and these improvements are explained by beneficial cellular and molecular changes in skeletal muscle and adipose tissue.

Researchers will compare 20 women with pGDM to 20 glucosetolerant without pGDM, who are matched on age, BMI and times since last pregnancy.

Participants will undergo a screening visit and examinations on two separate days before (day 1 and day 2) and two separate days after (day 3 and day 4) 8-weeks of HIIT, in all cases after an overnight fast (≥ 12 h). Day 1 and day 3 will include assessment of body composition and VO2max. On day 2 and day 4, the insulin sensitivity, substrate metabolism, and β-cell function of the participants will be examined by a Botnia-clamp combined by indirect calorimetry. Skeletal muscle biopsies from m. vastus lateralis and subcutaneous abdominal adipose tissue biopsies are taken in the basal and insulin-stimulated states of each clamp.

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Key information

Conditions

Gestational Diabetes Mellitus (GDM) Diabetes Mellitus Diabetes Mellitus, Type 2 Diabetes, Gestational Endocrine System Diseases Female Urogenital Diseases and Pregnancy Complications Glucose Metabolism Disorders High-Intensity Interval Training Metabolic Diseases Nutritional and Metabolic Diseases Pregnancy Complications Type 2 Diabetes (T2DM) Urogenital Diseases

Age range

25 year–45 year

Sex eligibility

Female

Study type

Interventional

Phase

Not applicable

Primary location

Steno Diabetes Center Odense, Odense University Hospital

Odense, Region Syddanmark, 5000, Denmark

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Age 25-45 years
  • BMI 20-35 kg/m2
  • 2-8 years since the last pregnancy
  • No known diabetes or PCOS
  • No previous bariatric surgery
  • No known disease
  • Be drug-naive
  • Have a regular menstrual cycle (23-35 days)
  • Not be pregnant or planning pregnancy during the study period
  • Low or moderate level of physical activity must be (max 2 hours of moderate exercise weekly).
  • All participants should be able to provide informed consent
  • Women without pGDM must not have known hypertension or first-degree relatives with diabetes.

Exclusion criteria

  • Abnormal cardiac stethoscopy, ECG or screening blood tests
  • Positive plasma GAD-65 antibodies
  • Positive plasma choriogonadotropine
  • Undiagnosed T2D based on fasting plasma glucose (≥ 7.0 mmol/mol), plasma HbA1c (≥ 48 mmol/mol), or 2-h plasma glucose during an oral glucose tolerance test (OGTT) (≥ 11.1 mmol/mol)
  • Dyslipidemia (plasma LDL-cholesterol > 5.0 mmol/l)
  • In women with pGDM: Undiagnosed severe hypertension (blood pressure > 160/100)
  • In women without pGDM: Undiagnosed hypertension (blood pressure >140/90 mmHg) or impaired glucose tolerance (fasting plasma glucose at 6.16.9 mmol/l, plasma HbA1c at 42-47 mmol/mol, or a 2-h glucose at 7.8-11.0 mmol/l during an OGTT).

Treatment and study plan

High-intensity interval training

Other

The training intervention consists of 8-weeks of HIIT combining rowing and cycling on ergometers with two supervised sessions weekly in small groups of up to 10 participants. All HIIT sessions will start with a 10-min warm-up period followed by training blocks of 5 x 1 min high-intensity intervals (100-110% of Wattmax corresponding to ≥ 85% of maximum heart rate (HRmax)) each interspersed by 1 min active or resting recovery. Between the training blocks, the participants will have a 4-min break in which they shift from cycling to rowing or vice versa. The number of training blocks will gradually increase from two to five blocks during the 8-week intervention period with one block being added every second week. Halfway through the HIIT-protocol the workload will be adjusted according to a midway VO2max test. Participants will wear a heart monitor during training sessions.

Primary outcomes

  1. β-cell function by OGTT

    Time frame: At screening visit.

    Will be estimated as the disposition index (DI) by oral glucose tolerance test (OGTT) derived indices of insulin sensitivity and insulin secretion, after a 2-hour OGTT (75g) with measurement of plasma glucose, serum insulin and serum C-peptide at 0, 30 and 120 min.

  2. β-cell function by Botnia-clamp

    Time frame: At examination day 2 and 4.

    β-cell function adjusted for insulin sensitivity will be determined by calculating the DI as a product of the acute insulin response to glucose (AIRg) and insulin-stimulated glucose infusion rate (GIR).

  3. Whole body composition (lean body mass and fat mass)

    Time frame: At examination day 1 and 3.

    Will be obtained by a dual-energy X-ray absorptiometry (DXA) scanning (Prodigy Advance, GE Healthcare, CHI, US)

  4. Lean body mass

    Time frame: At examination day 1 and 3.

    Will be obtained by a dual-energy X-ray absorptiometry (DXA) scanning (Prodigy Advance, GE Healthcare, CHI, US)

  5. Fat mass

    Time frame: At examination day 1 and 3.

    Will be obtained by a dual-energy X-ray absorptiometry (DXA) scanning (Prodigy Advance, GE Healthcare, CHI, US)

  6. Cardiorespiratory fitness (maximal oxygen consumptions (VO2-max))

    Time frame: At examination day 1 and 3.

    Will be determined by an incremental exercise test on a cycle ergometer (SRM Ergometer System, Jülich, DE) combined with mixed chamber cardiopulmonary exercise analyzer (Oxigraf, Model O2CPX, California, US)

  7. Insulin sensitivity by Botnia-clamp

    Time frame: At examination day 2 and 4.

    Consisting of a hyperinsulinemic-euglycemic clamp (insulin 40mU/min/m2 for 3 h) combined with a 60 min intravenous glucose tolerance test (IVGGT) using a glucose bolus (0.3 kg per kg body weight with a maximum of 25 g glucose).

Secondary outcomes

  1. Plasma-specific metabolomics by LC- and GC-MS

    Time frame: At examination day 2 and 4.

    Liquid chromatography (LC)- and gas chromatography (GS)-based mass spectrometry (MS) will be used to detection, identification, and quantitation of very large numbers of metabolites in the micro- and nano-molar range in body fluids, such as blood.

  2. Tissue-specific metabolomics by LC- and GC-MS

    Time frame: At examination day 2 and 4.

    Liquid chromatography (LC)- and gas chromatography (GS)-based mass spectrometry (MS) will be used to detection, identification, and quantitation of very large numbers of metabolites in the micro- and nano-molar range in body tissues.

  3. Proteomics

    Time frame: At examination day 2 and 4.

    To identify biological processes and signaling networks altered in women with pGDM and changed in response to HIIT, we will apply unbiased mass-spectrometry based proteome analysis of the skeletal muscle and adipose tissue biopsies.

  4. Phosphoproteomics

    Time frame: At examination day 2 and 4.

    To identify biological processes and signaling networks altered in women with pGDM and changed in response to HIIT, we will apply unbiased mass-spectrometry based phosphoproteome analysis of the skeletal muscle and adipose tissue biopsies.

  5. Transcriptional profiling and gene expression

    Time frame: At examination day 2 and 4.

    High-resolution transcriptional profiling of abdominal adipose tissue and skeletal muscle biopsies will be performed using total RNA sequencing with next generation sequencing (TruSeq® Stranded Total RNA Library Prep Gold; Illumina).

    Gene expressions are quantified using Targeted quantitative real-time PCR (qRT-PCR) and Western Blotting.

  6. Mitochondrial respiration

    Time frame: At examination day 2 and 4.

    Will be measured on permeabilized muscle fibers, and analyzed by measuring oxygen consumption when adding substrates, uncouplers, and inhibitors to the chambers of a high-resolution oxygraphy.

  7. Lipid droplets by TEM

    Time frame: At examination day 2 and 4.

    The morphology, volume, and localization of lipid droplets in muscle biopsies from the study cohorts will be determined by Transmission Electron Microscopy (TEM).

  8. Mitochondria by TEM

    Time frame: At examination day 2 and 4.

    The morphology, volume, and localization of mitochondria in muscle biopsies from the study cohorts will be determined by Transmission Electron Microscopy (TEM).

  9. Lipid droplet interaction with mitochondria by TEM

    Time frame: At examination day 2 and 4.

    The the physical interaction between lipid droplets and mitochondria in muscle biopsies from the study cohorts will be determined by Transmission Electron Microscopy (TEM).

  10. Protein abundance

    Time frame: At examination day 2 and 4.

    Protein abundance will be studied in skeletal muscle and adipose tissue biopsies by Western blotting procedures.

  11. Phosphorylation of enzymes

    Time frame: At examination day 2 and 4.

    Phosphorylation of enzymes will be studied in skeletal muscle and adipose tissue biopsies by Western blotting procedures.

Other outcomes

  1. Lipid profile

    Time frame: At examination day 2 and 4.

    Plasma total cholesterol, HDL-cholesterol, LDL-cholesterol, non-HDL-cholesterol and triglycerides determined by blood tests.

  2. HbA1c

    Time frame: At examination day 2 and 4.

    Determined by blood tests.

  3. Insulin

    Time frame: At examination day 2 and 4.

    Determined by blood tests.

  4. Glucose

    Time frame: At examination day 2 and 4.

    Determined by blood tests.

  5. C-peptide

    Time frame: At examination day 2 and 4.

    Determined by blood tests.

  6. Levels of systemic low-grade inflammation

    Time frame: At examination day 2 and 4.

    Circulating levels of adiponectin, leptin, interleukin-6 (IL-6), fibroblast growth factor 21 (FGF21), angiopoietin-like 4 (ANGPTL4) and growth differentiation factor 15 (GDF15) will be measured in bloodsamples.

Sponsors and collaborators

Lead sponsor

Odense University Hospital

Other

Collaborators

  • University of Southern Denmark

Registry information

Official study title

Deep Metabolic and Molecular Phenotyping of Women With Previous Gestational Diabetes Mellitus and the Responses to High-intensity Interval Training.

Acronym: GDM-HIIT

Important dates

Study start
2026
Primary completion
2028
Study completion
2028
First posted
May 5, 2026
Registry last updated
May 5, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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