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NCT Number: NCT02830646

Kidney Function Indexed Extracellular Volume Before and After Obesity Surgery

Obesity promotes chronic kidney disease and is accelerating its shift to the stage of renal replacement. Bariatric surgery is a treatment for severe or morbid obesity whose renal benefit is currently unknown. The glomerular filtration rate (GFR) is the best parameter to define the kidney function. It can be estimated using formulas by assaying endogenous markers (creatinine, cystatin C) or measured with an exogenous tracer glomerular filtration (51 Cr-EDTA).

Bariatric surgery alters the production of endogenous markers and the extracellular volume (VEC) with 2 important consequences on the assessment of GFR: the formula to estimate GFR is not possible to compare renal function before and after surgery because of the variation in production of endogenous glomerular filtration markers in the same subject; decreasing VEC predicted decreased GFR after surgery, since these parameters are in part proportional to each other.

Our working hypothesis is that bariatric surgery protects the kidneys of patients with chronic kidney disease. To demonstrate this, investigators propose to compare the ratio DFG / VEC before and after gastric bypass.

Goals The main objective is to measure the effect of gastric bypass on the report DFG / VEC. Secondary objectives are to assess the effect of gastric bypass on the albumin / urine creatinine and evaluate the performance of the main GFR estimating formulas in people with severe or morbid obesity.

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Key information

Conditions

Obesity Body Weight Nutrition Disorders Nutritional and Metabolic Diseases Overnutrition Overweight Pathological Conditions, Signs and Symptoms Signs and Symptoms

Age range

18 year–70 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

CHU de Nice

Nice, France

Who can participate

Healthy volunteers accepted: No

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

Inclusion criteria

  • Topic GFR estimated by having the simplified formula of MDRD <60 ml / min / 1.73 m²
  • Topic with BMI ≥ 40 kg / m², or ≥ 35 kg / m²
  • Subject having at least one comorbidity could be improved after surgery after failure of medical treatment: hypertension , OSAHS and other severe respiratory disorders, severe metabolic disorders, particularly type 2 diabetes , debilitating musculoskeletal diseases, steatohepatitis nonalcoholic .
  • Topic who signed the informed consent
  • Topic affiliated to the social security
  • Male or female Topics
  • Elderly 18 to 70 inclusive

Exclusion criteria

  • Non- Caucasian person because the necessary correction factors and not always available for the formula to estimate GFR ( Cockcroft , Salazar and Corcoran ) .
  • No major under guardianship
  • Nobody hospitalized without his consent and not protected by law
  • Private person of liberty
  • Pregnant Woman, knowing that a pregnancy test will be performed for women of childbearing age . Results will be communicated to the patient by a doctor of his choice.
  • Rapidly progressive glomerulonephritis
  • Nephrotic proteinuria ranking

Treatment and study plan

DFG mesure

Other

Measure the effect of gastric bypass on the report DFG / VEC.

Primary outcomes

  1. Ratio DFG / VEC

    Time frame: Month 12

    Average ratio DFG / VEC before and one year after gastric bypass

Secondary outcomes

  1. Albumin / urine creatinine

    Time frame: Month 12

  2. GFR estimation formula

    Time frame: Month 12

    GFR using the Cockcroft formulas , Salazar and Corcoran , simplified MDRD and CKD -EPI . Each of GFR estimation formula , we calculate the mean bias by the difference between the estimated value and the measured value and the percentage of patients with the value obtained by estimation is between -25 % and + 25 % in value measured ( awerage Within 50 or AW50 )

Sponsors and collaborators

Lead sponsor

Centre Hospitalier Universitaire de Nice

Other

Registry information

Official study title

Measurement of Kidney Function Indexed Extracellular Volume Before and After Obesity Surgery in Kidney Patients With Severe Obesity or Massive

Important dates

Study start
2015
Primary completion
2018
Study completion
2020
First posted
Jul 13, 2016
Registry last updated
Jun 16, 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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