Plantar Callosities and the Validity of Body Composition Assessment by Bio-impedance in Severely Obese Persons

Study Overview
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Brief Summary
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Studies have confirmed the association between plantar callosities and severely obese individuals. Bioelectrical impedance analysis (BIA) is an increasingly popular tool for estimating body composition because it is easy to use, noninvasive, relatively inexpensive, and can be performed across a wide range of subjects. Our hypotheses for this study are: (1)plantar callosities influence the body composition measurements obtained by bioelectrical impedance analysis BIA, and (2) BIA underestimates the percentage of body fat compared with air-displacement plethysmography (BodPod).

Detailed Description
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As the prevalence of obesity continues to increase, many parts of the world are progressively facing a rise in the number of people who fall under WHO obesity class 2 and 3. Since severe obesity is characterized by large alterations in body compartments when compared to overweight or non-obese individuals, there is a need for the evaluation of the body composition of severely obese persons. There is very few published research available on what methods of body composition measurements can be used on this population. Other studies have also shown the tendency of bioelectrical impedance analysis (BIA) instruments to underestimate percentage of fat mass and overestimate the percentage of fat free nass, compared with gold-standard techniques. We think that plantar callosities might have contributed to the lack of accurate measurements. Thus, the primary aim of this study is to determine whether plantar callosities influence the validity of body composition measurements obtained by BIA, using the InBody 720. The secondary aim is to assess the validity of the body composition measurements obtained by BIA (InBody 720) in severely obese individuals, using air-displacement plethysmography (BodPod) as the gold standard. Additionally, we will explore various sources of error using test-retest reliabilities by measuring body composition with different arm postures. We will examine this further to rule out the possibility of positions of measurement as a potential confounder of this study.

Official Title
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Plantar Callosities and the Validity of Body Composition Assessment by Bio-impedance in Severely Obese Persons

Conditions
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Obesity, Morbid

Intervention / Treatment
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* Device: Bioelectric impedance
* Device: Air displacement plethysmography


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adults (18-50 years old) class 2 and 3 obesity (BMI > 35 kg/m2) moderate to severe callosities Exclusion Criteria: Intractable plantar keratosis (IPK), which are painful plantar calluses located under the metatarsal heads. pregnancy menopause diseases that cause water retention (edema, renal insufficiency, hypertension, etc.)

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 50 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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Design Details

Primary Purpose: Diagnostic
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: body composition assessment<br>Bioelectric impedance measurement pre- and post removal of calluses and corns (pedicure), then air-displacement plethysmography (gold standard) | Device: Bioelectric impedance<br>* removal of calluses and corns by pedicure<br>* Other names: BIA;Device: Air displacement plethysmography<br> <br> * Other names: ADP;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Body composition | Bioelectric impedance (using InBody 720) at three standardized arm postures angled at 15, 45 and 90 degrees, in randomized order; Air displacement plethysmography (ADP,using BodPod) | 1 day | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Body constitution, Anthropometry, Electric impedance