Effect of Gastric Bypass on the Absorption of Metformin

NCT01013051 | Completed

• 1 other identifier: RES0002122
• Study Type: observational
• Target: 34
• Locations: 1 country
• Sites: 1

Brief Summary

Background: Gastric bypass is the most commonly performed type of bariatric (obesity) surgery, has dramatically increased in popularity and is now considered to be preferred treatments in severely obese patients that fail non-surgical therapy - particularly in patients with type 2 diabetes. Drug malabsorption is a potential concern post-gastric bypass because intestinal length is reduced. Purpose: The purpose of this controlled, pharmacokinetic study is to determine whether the absorption of a single dose of metformin, the first line drug treatment in patients with type 2 diabetes, is significantly reduced after gastric bypass. Methods: A single dose of standard release metformin 1000 mg will be administered to patients who have undergone gastric bypass and to patients who have not received surgery but are on the wait list (wait-listed controls). Blood sampling and urine sampling will occur in standardized fashion over the ensuing 24 hours to measure and compare the absorption of metformin between study arms. 34 patients total will be recruited. Significance: Following completion of this study, we will better understand how gastric bypass affects metformin absorption. Ultimately, this information will help to ensure that this patient population is receiving optimal doses of this important drug treatment.

Conditions

Obesity; Gastric Bypass

Keywords

obesity; gastric bypass; metformin; pharmacokinetics; absorption

Outcome Measures

Primary Outcomes (1)

• Area-under-the-curve of metformin absorption (0-infinity)

  cross-sectional

Secondary Outcomes (5)

• AUC (0-24h)

  cross-sectional

• tmax

  cross-sectional

• cmax

  cross-sectional

• AUC glucose (0-8h)

  cross-sectional

• bioavailability of metformin (urine metformin concentration from 0-infinity)

  cross-sectional

Study Arms (2)

Post Gastric Bypass

Obese Controls

age, BMI, gender matched

Eligibility Criteria

• Age: 18 Years - 60 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64)
• Sampling Method: Probability Sample

Study Population

Post gastric bypass and obese controls 1. Male and Female 2. 18 - 60 years old 3. ≥ 3 months post-RYGB surgery or wait listed for bariatric surgery 4. Able to provide written informed consent.

You may qualify if:

• Patients living within and around Edmonton that have been referred to the Alberta Health Services Weight Wise Program

You may not qualify if:

• Undergone or undergoing revision of a previous bariatric procedure
• Any major post-operative gastrointestinal complications, such as an anastomotic leak, outlet obstruction or persistent vomiting
• Currently on metformin therapy
• Any contraindications to metformin therapy such as:
• allergy to the drug
• chronic metabolic acidosis
• history of lactic acidosis
• liver failure or baseline liver enzymes higher than 3-fold above the upper limit of normal
• congestive heart failure
• renal failure (glomerular filtration rate \< 60 ml/min)
• alcoholism
• acute illness
• fatty liver disease
• Pregnant or nursing
• Not taking furosemide or nifedipine (both drugs may increase metformin absorption by 15-20%)the day of visit 2.

Sponsors & Collaborators

• University of Alberta: lead

Study Sites (1)

University of Alberta Hospital Clinical Investigation Unity

Edmonton, Alberta, T6G2B7, Canada

Location

MeSH Terms

Conditions

Obesity

Condition Hierarchy (Ancestors)

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

Study Officials

• Raj Padwal, MD

  University of Alberta

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: observational
• Observational Model: CASE CONTROL
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER

Study Record Dates

• First Submitted: November 12, 2009
• First Posted: November 13, 2009
• Study Start: September 1, 2009
• Study Completion: December 1, 2010
• Last Updated: March 3, 2011

Record last verified: 2011-03

Locations

CA (1)