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Effects of Obesity Surgery on Renal Function

This study has been completed.
Sponsor:
ClinicalTrials.gov Identifier:
NCT01507350
First Posted: January 10, 2012
Last Update Posted: August 11, 2017
The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
Information provided by (Responsible Party):
Carel Le Roux, Imperial College London
  Purpose

Increasing risk of impaired renal function as a result of obesity is well known. Early data has postulated that weight loss might improve kidney function, but the evidence is rather limited due to the difficulties in measuring glomerular filtration rate(GFR) after weight loss. Cystatin C, GFR measurement using Cockcroft-Gault (CCG) and Modification of Diet in Renal Disease (MDRD) equations, have all yield conflicting results after weight loss surgery.

The study aim to assess:

  1. use of 51Cr-EDTA Clearance as the methodological gold standard in evaluating changes in renal function before and after weight loss surgery.
  2. the reliability of using MDRD, CCG and Cystatin C in measuring GFR after weight loss surgery
  3. the differences in alterations in renal function dependent on the surgical procedures( gastric bypass, gastric band, sleeve gastrectomy).
  4. the use of urine albumin/creatinine ratio in detecting alterations in microalbuminuria.

Condition
Impaired Renal Function

Study Type: Observational
Study Design: Observational Model: Cohort
Time Perspective: Prospective
Official Title: Effects of Obesity Surgery on Renal Function

Resource links provided by NLM:


Further study details as provided by Carel Le Roux, Imperial College London:

Primary Outcome Measures:
  • Changes in glomerular renal function after weight loss surgery as measured by 51Cr-EDTA Clearance [ Time Frame: 12 months ]
    GFR assessment using the abbreviated and extended MDRD formulae, CCG and the 51Chromium-EDTA clearance.


Secondary Outcome Measures:
  • Microalbuminuria, creatinine clearance, Cystatin C. [ Time Frame: 12 months ]
    Compare different ways of measuring renal function after weight loss surgery.

  • Differences in alterations in renal function dependent on the used surgical procedure. [ Time Frame: 12 months ]
    Compare the renal function among the three different surgical cohorts, namely gastric bypass, gastric band, and sleeve gastrectomy.


Enrollment: 45
Study Start Date: June 2011
Study Completion Date: August 1, 2017
Primary Completion Date: June 1, 2017 (Final data collection date for primary outcome measure)
Groups/Cohorts
gastric band
Patients having gastric band will have blood and urine tests, and 51 Cr-EDTA clearance to assess renal function. These are taken before and after the surgery at 6 weeks , 6 months and 12 months.
sleeve gastrectomy
Patients having sleeve gastrectomy will have blood and urine tests, and 51 Cr-EDTA clearance to assess renal function. These are taken before and after the surgery at 6 weeks , 6 months and 12 months.
gastric bypass
Patients having gastric bypass will have blood and urine tests, and 51 Cr-EDTA clearance to assess renal function. These are taken before and after the surgery at 6 weeks , 6 months and 12 months.

Detailed Description:

This is a prospective study on obese human subjects undergoing bariatric surgery. Forty-five patients due to undergo gastric bypass (n=15), gastric banding (n=15), and gastric sleeve surgery (n=15) will be recruited.

Subjects will be screened prior to entry into the study with full history, examination, routine bloods (FBC, U+E, liver function tests, and glucose).

  1. Blood samples and 24h urine specimens are taken at four time points: preoperatively as well 6 weeks, 6 and 12 months postoperatively.
  2. The following methods of GFR assessment will be executed the same time point: measurement of serum creatinine concentration, calculation of the abbreviated and extended MDRD formulae, CCG, creatinine clearance, serum Cystatin C concentration and the 51Chromium-EDTA clearance.

Inclusion criteria

  1. Patients with a BMI of >35kg/m2 approved for obesity surgery based on the NICE criteria.
  2. Patients with a GFR <60 mL/min/1.73

Exclusion criteria

1. Allergy to chromium

  Eligibility

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 65 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population
  1. Patients with a BMI of >35kg/m2 approved for obesity surgery based on the NICE criteria.
  2. Patients with a GFR <60 mL/min/1.73 m2
Criteria

Inclusion Criteria:

  • Patients with a BMI of >35kg/m2 approved for obesity surgery based on the NICE criteria.
  • Patients with a GFR <60 mL/min/1.73 m2

Exclusion Criteria:

  • Allergy to chromium
  Contacts and Locations
Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT01507350


Locations
United Kingdom
Charing Cross Hospital
London, United Kingdom, W6 8RF
Sponsors and Collaborators
Imperial College London
Investigators
Principal Investigator: Carel W le Roux, MBChB, PhD Imperial College London
  More Information

Responsible Party: Carel Le Roux, Consultant metabolic medicine, Imperial College London
ClinicalTrials.gov Identifier: NCT01507350     History of Changes
Other Study ID Numbers: BSR
First Submitted: January 6, 2012
First Posted: January 10, 2012
Last Update Posted: August 11, 2017
Last Verified: August 2017
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

Keywords provided by Carel Le Roux, Imperial College London:
obesity related glmerulopathy
51 Cr-EDTA clearance
impaired renal function
gastric band
GFR measurement
gastric bypass
sleeve gastrectomy

Additional relevant MeSH terms:
Obesity
Renal Insufficiency
Overnutrition
Nutrition Disorders
Overweight
Body Weight
Signs and Symptoms
Kidney Diseases
Urologic Diseases