الفهرس 
Pathology of ObesityOnly 14 pages are availabe for public view
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Abstract
Obesity is a medical condition in which excess body fat has accumulated to the extent that it may have an adverse effect on health. It is related to metabolic disorders and hypertension and to an increased frequency of total mortality and cardiovascular disease.
Obesity is an exaggeration of normal adiposity and is a central player in the pathophysiology of diabetes mellitus, insulin resistance, dyslipidemia, hypertension, and athero-sclerosis, largely because of its secretion of excessive adi-pokines.
Obesity is a major contributor to the metabolic dysfunction involving lipid and glucose, but on a broader scale, it influences organ dysfunction involving cardiac, liver, pulmonary, endocrine, and reproductive functions. Finally, obesity contributes to immune dysfunction from the effects of its secretion of inflammatory adipokines and is a major risk factor for many cancers. Because of the accelerating effects it has on the worsening of metabolic syndrome and cancer, obesity has the potential to be pro¬foundly detrimental to our species if major methods of prevention and/or effective treatment are not realized. It is essential then to institute major educational efforts aimed at promoting better habits of eating and physical exercise.
These lifestyle changes may be complemented by interventional procedures like the less-invasive gastric balloon treatment to help patient with the fight against obesity. To measure body composition several methods are available: bioelectrical impedance analysis and bioimpedance spectroscopy, dual energy X-ray absorptiometry, dilution techniques, three-dimensional photonic scanner, ultrasound, MRI and CT. BIA measures the impedance or resistance to a small electrical current as it travels through the body’s water pool. An estimate of TBW is acquired from which total body FFM is calculated.
Bioimpedance spectroscopy (BIS) or multifrequency BIA allows for the differentiation of TBW into intracellular water (ICW) and extracellular water (ECW) compartments, which is useful to describe fluid shifts and fluid balance and to explore variations in levels of hydration. Dual energy X-ray absorptiometry systems provide whole-body and regional estimates of three main components: bone mineral, bone-free FFM, and fat mass and the DXA technique is accepted as a non-invasive measurement method that can be applied in humans of all ages. Dilution techniques use water for calculations of body compostion. Deuterated (2H), tritated (3H), or oxygen-labeled (18O) water can be used to determine TBW by dilution. These isotope dilution techniques allow for the evaluation of fat mass and FFM in which it is assumed that the hydration of FFM is stable.
The air displacement plethysmography (ADP) method for measuring body volume and hence fat mass is an alternative to the underwater weighing (UWW) method requiring no water submersion and therefore is better tolerated by individuals. ADP as determined by the measures the volume of air displaced by the individual.
The Three-dimensional photonic scanner is a digitized optical method to generate a three-dimensional (3D) photonic image of an object and individual. This approach generates values for total and regional body volumes and dimensions. The ultrasound can be used to measure the thickness of fat between the skin and the muscle. A transducer probe emits, through the skin, an ultrasonic wave of which a part is reflected at the fat muscle interface. MRI quantifies the distribution of adipose tissue into visceral, subcutaneous, and more recently intermuscular depots. In computed tomography (0, an x-ray beam is scanned from a source rotating around the patient and passes through the patient. The exit transmission intensity is monitored by a series of detectors. The x-ray beam creates cross sectional slices about 10 mm thick through the patient. The transmission at any angle can be used to calculate the average attenuation coefficient along the length of the x-ray beam.
The attenuation coefficients are reported in terms of Hounsfield units, in which bone and other dense materials are equal to +1000, water is equal to zero, and air is equal to -1000. The differences in attenuation coefficients among fat-free mass, adipose tissue, and bone make this technique appropriate for quantifying separate adipose tissue depots and whole-body composition.
Furthermore, this imaging technique permits direct visualization of internal adipose tissue compartments not accessible by conventional anthropometric methods. CT scanning has been used for the evaluation of subcutaneous abdominal adipose tissue.
Of all this body composition measurement methods CT has been shown to be highly reliable in the evaluation of adipose tissue, fat-free mass and skeletal muscle. CT is considered more accurate than any other measurement technique and is therefore the gold standard for body fat measurements. After diagnosis of obesity different therapies can be chosen. Diet therapy and exercise alone have shown not to be sufficient for effective weight loss. An interesting non-invasive method is the placement of an intragastric balloon.
Different types of intragastric balloon are avalaible: the Bioenterics Intragastric Balloon, Heliosphere Bag, Adjustable Totally Implantable Intragastric Prosthesis, Semistationary Antral Balloon, Silimed Gastric Balloon. endoscopic duodenal-jejunal bypass sleeve. Of all these balloons the bioenteric gastric balloons are the best balloons to be used at this moment. They result in effective weight loss, are well tolerated and give minor complications that can be easily solved. The bioenteric gastric balloons are the balloons of choice.