Influence of Obesity and Gastric Bypass on Medication Absorption

Study Overview
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Brief Summary
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Patients who have scheduled a gastric bypass (RYGB) in UZ Leuven, will be questioned preoperatively and one, three, six and twelve months after gastric bypass surgery. The purpose of this study is to explore current practice regarding the use of medication and medication counseling after RYGB and to examine the changes in dietary pattern before and after RYGB.

Detailed Description
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Target group: patients who have scheduled a gastric bypass in UZ Leuven. Patients will be questioned preoperatively and one, three, six and twelve months after gastric bypass surgery. Each assessment will be performed during a routine consultation. The following aspects will be investigated: Medication The investigators have composed a questionnaire to examine which drugs the patients use, adherence, information received about medication and from whom,… Clinical parameters Every consultation, concentrations of hemoglobin, iron, hepcidin, vitamin B12,…. and a 24h urine collection to determine calcium excretion will be collected. Dietary intake The investigators will ask patients to keep a food record during two non-consecutive days preceding each consultation. In this food record patients have to note all consumed foods and beverages with the right/estimated amounts. This makes it possible to see the changes of the composition of the meals before and after RYGB. Body composition

Official Title
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Influence of Obesity and Gastric Bypass on Medication Absorption: Prospective Follow-up of Patients

Conditions
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Obesity

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients who have scheduled gastric bypass Use of at least one chronic drug (including contraception) Exclusion Criteria: Patients who have undergone another form of bariatric surgery before RYGB

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Gastric Bypass<br>Obese patients who have scheduled a gastric bypass | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Medication use | Patients will be questioned preoperatively and one, three, six and twelve months after gastric bypass surgery. A questionnaire will be used to examine which drugs patients use and to what level they are adherent to treatment recommendations. | one year | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in dietary pattern before and after RYGB | The investigators will ask patients to keep a food record during two non-consecutive days preceding each consultation. In this food record patients have to note all consumed foods and beverages with the right/estimated amounts. This makes it possible to see changes of the composition of the meals before and after RYGB. The correlation between the dietary/total intake and clinical parameters will be investigated. | one year | 
| Medication counseling | Patients will be questioned preoperatively and one, three, six and twelve months after gastric bypass surgery. A questionnaire will be used to examine what kind of information they received about medication use pre- and post-RYGB. | one year | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Obesity, Gastric bypass, Medication, Medication counseling, Dietary pattern, Follow-up of patients