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AzTrials

ObesityBARIA-DDZNCT01477957

The Effect of Bariatric Surgery on Insulin Sensitivity and Energy Metabolism

An observational study of Obesity and Diabetes Mellitus, Type 2, run by German Diabetes Center at 1 site in Germany.

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 purpose of this study is: 1. To explore to what extent insulin sensitivity, energy metabolism and ectopic lipid storage can be improved by bariatric surgery 2. To explore to what extent hepatic and muscular disorders of energy metabolism occur in patients with obesity (degree 2-3) 3. Read more about this study

Who is it for?
Ages 20 to 70 yearsHealthy volunteers can take part
Conditions the study is for
Obesity, Diabetes Mellitus, Type 2
What is being tested?
surgery
Type of treatment
Surgery or procedure
How many people
450 participants
Where
1 siteGermany
Study dates
Sep 2012to Dec 2028
Phase
Observational
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 20 to 70 years
  • All sexes
  • Healthy volunteers accepted
  • Adult, Older adult

Study population: People with obesity and various stages of MASLD, that qualify for bariatric surgery.

Who may be able to join

  • Aged ≥ 20 years- ≤ 70 years
  • BMI 20- 25 kg/m 2 normal- weight group
  • BMI 35- 39,9 kg/m 2 (Obesity grade 2)
  • BMI >40 kg/m 2 (Obesity grade 3)

Who cannot join

  • Acute illness 2 weeks before start of examination
  • Autoimmune or Immune disorder diseases (Leukozyten < 5000/µl
  • Renal insufficiency (Kreatin > 1,5 mg/dl)
  • Heart disease, condition after heart attack
  • Anemia (Hb <12g/l, controlled before every day of examination) or blood donations 4weeks before examination.
  • Participation in another trial within the last 2 weeks
Show all 18Show fewer
  • Pharmacological- immunotherapy (Cortisol, Antihistaminika, ASS)
  • Thyroid disorders
  • Glitazone Therapy
  • Pregnancy, Lactation, Menstruation
  • Smoking cigarettes, Alcohol- and drug abuse
  • Psychiatric disorders
  • Risk for/ or diagnosed HIV/ AIDS or Hepatitis B/C
  • Liver disease, which are not caused by non- alcoholic steato- hepatitis
  • Working on night shifts or irregular rhythm of night- day
  • Impaired wound healing or clotting disorders
  • Allergic reaction to local anesthetics
  • Malignant cancer

Trial locations and contacts

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

Sabine Kahl, MD contact

0049211-3382 ext. 698

sabine.kahl@ddz.de

Germany1 site, 1 recruiting

  • German Diabetes Center

    Düsseldorf, North Rhine-Westphalia, 40225

    Michael Roden, Prof., MD, 0049211-3382 ext. 201, michael.roden@ddz.de

    Sabine Kahl, MD, 0049211-3382 ext. 698, sabine.kahl@ddz.de

    Recruiting

Other trials in Germany

About this study

Official title: The Effect of Bariatric Surgery on Insulin Sensitivity and Energy Metabolism in Obesity Grade 2 -3

The purpose of this study is:

  1. To explore to what extent insulin sensitivity, energy metabolism and ectopic lipid storage can be improved by bariatric surgery
  2. To explore to what extent hepatic and muscular disorders of energy metabolism occur in patients with obesity (degree 2-3)
  3. To explore whether the steato liver occurring in patients with obesity (degree 2-3) is associated with the degree of liver inflammation
Read the detailed description

Insulin resistance strongly relates to ectopic lipid deposition in skeletal muscle and the liver, which correlate with insulin resistance. Lipid metabolites accumulating in skeletal muscle and the liver are thought to impair insulin signalling and thereby reduce glucose uptake and glycogen storage. Insulin resistant humans frequently present with decreased mitochondrial function in skeletal muscle which might contribute to lipid accumulation and the development of insulin resistance. Metabolic dysfunction-associated steatotic liver disease comprises steatosis, steatohepatitis and cirrhosis. MASLD correlates with insulin resistance, increased risk for cardiovascular diseases and type 2 diabetes. The mechanisms leading from steatosis to steatohepatitis and insulin resistance in the liver are yet unclear. Bariatric surgery aims at profound reduction of body weight. Also, it frequently and rapidly leads to normalization of glucose tolerance even before the onset of body weight reduction. The underlying mechanisms are yet unclear. In this study we aim to explore the mechanisms underlying the onset of insulin resistance and steatohepatitis in patients with steatosis and to identify the mechanisms leading to improved glucose tolerance in humans after bariatric surgery. We test the following hypotheses: increased lipid availability leads to (i) increased lipid oxidation and oxidative stress (ii) accumulation of lipid metabolites that impair insulin signalling (iii) bariatric surgery improves insulin sensitivity by increasing lipid oxidation.

This study will contribute to the understanding of MASLD and will help to identify new targets for the therapy of diabetes.

Being tested
surgery
Keywords
weight loss after bariatric surgery, Insulin sensitivity, insulin resistance
Medical subject headings
Obesity, Diabetes Mellitus, Type 2, Insulin Resistance

What participants receive

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

  • surgeryProcedure or surgery

    Also called bariatric surgery

    biliopancreatic diversion, gastric banding, gastric sleeve resection

Study groups in NCT01477957
Study groupRoleWhat they receive
Surgerybariatric surgery
Receives: Procedure: surgery

What is being measured

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

  1. Energy metabolism

    whole body substrate oxidation, ex vivo mitochondrial function via measurement of high resolution respirometry and in vivo mitochondrial function via measurement of ATP production

    Measured: 5 years

Secondary outcomes (2)

  1. weight loss

    body weight and body composition before and after bariatric surgery

    Measured: 5 years

  2. Insulin sensitivity

    Whole body glucose uptake and endogenous glucose production as measure of skeletal muscle and hepatic insulin sensitivity

    Measured: 5 years

Timeline

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

  1. First posted23 Nov 2011 (estimated)
  2. Study startSep 2012
  3. Primary completionDec 2028 (estimated)
  4. Study completionDec 2028 (estimated)

Resources

More details

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

Study design
Study type
Observational
Observational model
Case-control
Time perspective
Prospective
Enrolment
450 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT01477957
Sponsor's protocol ID
BARIA-DDZ
Acronym
BARIA-DDZ
Status last verified
Dec 2024
First submitted
13 Nov 2011
Last updated
10 Jan 2025
Results posted
No
Data monitoring committee
No

Publications

  • Koliaki C, Szendroedi J, Kaul K, Jelenik T, Nowotny P, Jankowiak F, Herder C, Carstensen M, Krausch M, Knoefel WT, Schlensak M, Roden M. Adaptation of hepatic mitochondrial function in humans with non-alcoholic fatty liver is lost in steatohepatitis. Cell Metab. 2015 May 5;21(5):739-46. doi: 10.1016/j.cmet.2015.04.004.

    PubMed 25955209

  • Miya A, Tura A, Shokouhmehr A, Esposito I, Yavas A, Granderath FA, Schlensak M, Huttasch M, Xourafa G, Heilmann G, Kahl S, Roden M, Schrauwen P. Insulin resistance, not hepatic histological features, is the dominant correlate of insulin clearance in class 3 obesity. Diabetes Res Clin Pract. 2026 Aug 2:113481. doi: 10.1016/j.diabres.2026.113481. Online ahead of print.

    PubMed 42543084

  • Kahl S, Strassburger K, Pacini G, Trinks N, Pafili K, Mastrototaro L, Dewidar B, Sarabhai T, Trenkamp S, Esposito I, Schlensak M, Granderath FA, Roden M. Dysglycemia and liver lipid content determine the relationship of insulin resistance with hepatic OXPHOS capacity in obesity. J Hepatol. 2025 Mar;82(3):417-426. doi: 10.1016/j.jhep.2024.08.012. Epub 2024 Aug 31.

    PubMed 39218222

  • Kovac L, Gancheva S, Jahnert M, Sehgal R, Mastrototaro L, Schlensak M, Granderath FA, Rittig K, Roden M, Schurmann A, Kahl S, Ouni M. Different effects of bariatric surgery on epigenetic plasticity in skeletal muscle of individuals with and without type 2 diabetes. Diabetes Metab. 2024 Sep;50(5):101561. doi: 10.1016/j.diabet.2024.101561. Epub 2024 Jul 6.

    PubMed 38977261

  • Sarabhai T, Kahl S, Gancheva S, Mastrototaro L, Dewidar B, Pesta D, Ratter-Rieck JM, Bobrov P, Jeruschke K, Esposito I, Schlensak M, Roden M. Loss of mitochondrial adaptation associates with deterioration of mitochondrial turnover and structure in metabolic dysfunction-associated steatotic liver disease. Metabolism. 2024 Feb;151:155762. doi: 10.1016/j.metabol.2023.155762. Epub 2023 Dec 19.

    PubMed 38122893

  • Pafili K, Kahl S, Mastrototaro L, Strassburger K, Pesta D, Herder C, Putzer J, Dewidar B, Hendlinger M, Granata C, Saatmann N, Yavas A, Gancheva S, Heilmann G, Esposito I, Schlensak M, Roden M. Mitochondrial respiration is decreased in visceral but not subcutaneous adipose tissue in obese individuals with fatty liver disease. J Hepatol. 2022 Dec;77(6):1504-1514. doi: 10.1016/j.jhep.2022.08.010. Epub 2022 Aug 19.

    PubMed 35988689

  • Apostolopoulou M, Gordillo R, Koliaki C, Gancheva S, Jelenik T, De Filippo E, Herder C, Markgraf D, Jankowiak F, Esposito I, Schlensak M, Scherer PE, Roden M. Specific Hepatic Sphingolipids Relate to Insulin Resistance, Oxidative Stress, and Inflammation in Nonalcoholic Steatohepatitis. Diabetes Care. 2018 Jun;41(6):1235-1243. doi: 10.2337/dc17-1318. Epub 2018 Mar 30.

    PubMed 29602794

Questions about this trial

What is this clinical trial studying?

An observational study of Obesity and Diabetes Mellitus, Type 2, run by German Diabetes Center at 1 site in Germany.

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 18 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 10 Jan 2025. 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 Germany. 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 Sabine Kahl, MD (0049211-3382 ext. 698, sabine.kahl@ddz.de), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Energy metabolism (time frame: 5 years). 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 NCT01477957, which also lists 7 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 10 Jan 2025; AzTrials last refreshed its copy on 26 Oct 2026.

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