ClinicalTrials.gg
RecruitingNCT01477957BARIA-DDZUpdated Jan 10, 2025

The Effect of Bariatric Surgery on Insulin Sensitivity and Energy Metabolism

An observational study in Obesity and Diabetes Mellitus, Type 2, sponsored by German Diabetes Center. Recruiting at 1 site in Germany. Open to participants aged 20 Years to 70 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-01-10.

Sponsored by German Diabetes Center · Observational

Study type
Observational
Model
Case-control
Time perspective
Prospective
Enrollment
450
Ages
20 Years to 70 Years
Sex
All
01

Study 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. 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.

02

Conditions studied

  • Obesity
  • Diabetes Mellitus, Type 2

Keywords

  • weight loss after bariatric surgery
  • Insulin sensitivity
  • insulin resistance
03

In context

Obesity

11,522 studies on the registry are indexed under Obesity; 2,033 are open to participants now.

This study's planned enrollment of 450 is above the median of 114 across 2,154 observational studies indexed under Obesity.

Browse Obesity studies →

Lead sponsor

German Diabetes Center is the lead sponsor of 30 studies on the registry; 8 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
20 Years to 70 Years
Sexes eligible
All
Accepts healthy volunteers
Yes
Sampling method
Non-probability sample

Study population

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

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  • Aged ≥ 20 years- ≤ 70 years
  • 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)

Exclusion criteria

Exclusion Criteria:

  • Acute illness 2 weeks before start of examination
  • or Immune disorder diseases (Leukozyten \< 5000/µl
  • Renal insufficiency (Kreatin > 1,5 mg/dl)
  • Heart disease, condition after heart attack
  • Anemia ( \<12g/l, controlled before every day of examination) or blood donations 4weeks before examination.
  • Participation in another trial within the last 2 weeks
  • Pharmacological- immunotherapy (Cortisol, Antihistaminika, ASS)
  • Thyroid disorders
  • Glitazone Therapy
  • Pregnancy, Lactation, Menstruation
  • Smoking cigarettes, Alcohol- and drug abuse
  • Psychiatric disorders
  • Risk for/ or diagnosed / AIDS or /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
Terms in these criteria, in plain language(5)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

BMI (body mass index)

Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.

What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.

Autoimmune disease

A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.

Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.

Hemoglobin (Hb)

The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).

HIV

The human immunodeficiency virus, which weakens the immune system.

Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.

Hepatitis B tests

Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.

Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.

05

Study design

Observational model
Case-control
Time perspective
Prospective
Enrollment
450 participants (estimated)
Patient registry
No

Groups and cohorts

  • Surgery

    bariatric surgery

    Procedure: surgery

Interventions

  • Proceduresurgery

    biliopancreatic diversion, gastric banding, gastric sleeve resection

    Also known as: bariatric surgery

06

What researchers measure

Primary outcomes

  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

    Time frame: 5 years

Secondary outcomes

  1. weight loss

    body weight and body composition before and after bariatric surgery

    Time frame: 5 years

  2. Insulin sensitivity

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

    Time frame: 5 years

07

Study locations

1 of 1 sites recruiting
08

References and documents

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 ↗
  • 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 ↗

Related links

09

Timeline

Tracking since Sep 25, 2026
Not marked actual or estimatedDates not marked actual or estimated

The record gives a start of Sep 2012, a primary completion of Dec 2028 and a completion of Dec 2028. It does not say whether these dates are actual or estimated.

How these figures are worked out, and which studies are left out of them.

Registered
Nov 13, 2011
First posted
Nov 23, 2011
Start
Sep 2012
Primary completionEst.
Dec 2028
CompletionEst.
Dec 2028
Last update
Jan 10, 2025
What these dates mean
Start.
When the first participant enrolled; while estimated, when the study expects to open to recruitment.
Primary completion.
When the last participant was examined or treated to collect data for the study's main question, its primary outcome. A study that stopped early gives the date its data collection stopped.
Completion.
When the last participant's last visit took place, for every outcome, secondary ones and side effects included: the end of the study. Often later than primary completion, sometimes the same day.
Actual and Est.
Actual means the registry says the date has happened. Est. (estimated) is a date the sponsor plans or expects. It can still move, and the sponsor is expected to change it to actual once it has passed.
No changes since tracking began. The registry record was last updated on Jan 10, 2025, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT01477957
Lead sponsor
German Diabetes Center
Collaborators
Dep.of General-, Visceral- and Pediatric Surgery, HHU, Duesseldorf, Germany, Dep.for Metabolic Diseases, HHU, Duesseldorf, Germany, Hospital Neuwerk, Mönchengladbach, Duesseldorf, Germany
Responsible party
Sponsor
First posted
Nov 23, 2011
Start date
Sep 2012
Primary completion
Dec 2028 (estimated)
Completion
Dec 2028 (estimated)
Last update
Jan 10, 2025

Study contacts

Sabine Kahl, MD
Contact
sabine.kahl@ddz.de
0049211-3382 ext. 698
Michael Roden, Prof., MD
principal investigator · German Diabetes Center

Oversight

Data monitoring committee
No
View the source record on ClinicalTrials.gov ↗

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