New Body Mass Index (BMI) Cut-offs for the Diagnosis of Obesity and Comorbidities

Study Overview
=================
Brief Summary
-----------------
Obesity is a serious medical problem because it increases the risk of cardiovascular disease (CVD), type 2 diabetes mellitus, and certain forms of cancer. The definition of obesity is based on an excess of body fat, not of BMI. However, BMI is the reference used to establish a graded classification of weight relative to height. Although BMI is widely used as a simple surrogate measure of body fat and has been shown to correlate closely with adiposity, it would be more appropriate to determine body fat percentage and to use this value for classification purposes. The present study contemplates the determination of the per cent body fat with the aim of establishing new diagnostic and therapeutic criteria according to the associated comorbidities.

Detailed Description
-----------------
The prevalence of overweight and obesity has increased alarmingly in the last decades. Obesity is a serious medical problem because it increases the risk of hypertension, type 2 diabetes mellitus, coronary heart disease, sleep-breathing disorders, and certain forms of cancer. Obesity is defined medically as a state of increased adipose tissue of sufficient magnitude to produce adverse health consequences. The definition of obesity is based on an excess of body fat, not of BMI. However, BMI is the reference used to establish a graded classification of weight relative to height. Although BMI is widely used as a simple surrogate measure of body fat and has been shown to correlate closely with adiposity, it would be more appropriate to determine body fat percentage and to use this value for classification purposes. The present study contemplates the determination of the per cent body fat (by air displacement plethysmography) in more than 5,000 subjects representing the whole BMI range, with the aim of establishing new diagnostic and therapeutic criteria according to the associated comorbidities. The specific objectives are: a) To know the body fat percentage means for normal weight, overweight and obesity for both sexes. b) To know the body fat percentage means for normal weight, overweight and obesity for the different age ranges. c) To analyse the relationship between body fat percentage and BMI values in order to detect misclassified individuals. d) To establish new cut-offs for body fat percentage and the normality ranges according to its relationship with cardiovascular risk factors that could be useful in the diagnosis and therapy of obesity.

Official Title
-----------------
Usefulness of the Determination of Body Composition for Establishing New Cut-offs for the Diagnosis and Follow-up of Obesity and Comorbidities

Conditions
-----------------
Obesity, Overweight, Diabetes Mellitus, Type 2

Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: BMI >18.5 No major organ disease unrelated to excess body weight Exclusion Criteria: Pregnancy/lactation History of eating disorder or major psychiatric illness

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------
What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Differences in body fat | For classically defined BMI categories (normalweight, overweight and obesity) body fat will be assessed by air-displacement plethysmography (Bod-Pod) | Baseline | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Differences in glycemic control | For classically-defined BMI categories measurement of fasting plasma glucose, insulin HOMA as well as response to OGTT will be related to actual body adiposity. | Baseline | 
| Differences in cardiovascular risk factors | For classically-defined BMI categories measurement of circulating total cholesterol, LDL-cholesterol, HDL-cholesterol, fibrinogen, C-reactive protein, homocysteine, von Willebrand factor and adipokines will be related to actual body adiposity. | Baseline | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Body mass index, Body fat, Obesity, Overweight, Diabetes Mellitus, Type 2, Air displacement plethysmography