The Effect of Bariatric Surgery on Thyroid Function and Morphology

Study Overview
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Brief Summary
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The aim is to evaluate the effect of dramatic weight loss after bariatric surgery on thyroid function (thyroid hormone levels and particulary morphological changes) in the short and long-term setting of a cross-sectional study. A particular focus will be made with regard to putting into correlation preoperative thyroid function abnormalities and postoperative changes over time with respect to the type of bariatric intervention carried out.

Detailed Description
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Background: Over the last decades, there has been an increase in obesity in virtually all population groups with approximately 1.6 billion adults worldwide estimated to be overweight in 2005 and 400 million of these people qualifying as being obese. Although hormonal disturbances may play a certain role in the development of obesity, more important are the possible consequences of obesity and the influence of surgically-induced rapid weight loss on overall endocrine function of these patients. Studies evaluating the effect of weight loss on thyroid function show inconsistent results. Whilst some authors have shown that weight loss after bariatric surgery may have a positive effect on thyroid dysfunction, especially in individuals with preoperative subclinical hypothyroidism 1 resulting in normalisation of TSH levels, others fail to show any significant postoperative changes. Objective: To evaluate the effect of dramatic weight loss after bariatric surgery on thyroid function (thyroid hormone levels and particularly morphological changes) in the short and long-term in the setting of a cross-sectional study. A particular focus will be made with regard to putting into correlation preoperative thyroid function abnormalities and postoperative changes over time with respect to the type of bariatric intervention carried out. Methods: BMI, thyroid hormones (TSH, fT3, fT4 levels), need for thyroxin substitution (or equivalent medication) as well as pre- and postoperative morphological changes in the thyroid gland (usually via sonography)and Leptin values will be assessed retrospectively.

Official Title
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The Effect of Bariatric Surgery on Thyroid Function and Morphology, a Retrospective Study

Conditions
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Thyroid Function, Obesity

Intervention / Treatment
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* Procedure: Bariatric surgery


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients who underwent bariatric surgery between 1998 and 2007 Exclusion Criteria age >18 years

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

| Intervention/Treatment |
| --- |
|Procedure: Bariatric surgery|gastric banding, gastric bypass or vertical gastroplasty either open or laparoscopic or a combination of any|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| thyroid hormone levels (change in) |  | preoperative, 3, 6 and 12 months postoperative | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| morphological changes of the thyroid gland |  | up to 12 months postoperatively | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Thyroid gland, bariatric surgery, weight loss, thyroid hormones, adult, morbid obesity, cohort