Bariatrics

Recent reports estimate that the proportion of individuals who are overweight in the United States surpasses 50% of the adult population. Such a staggering statistic has associated with it profound ramifications. Excess weight is a major contributor to serious health conditions that affect millions of people and can result in early death. Aside from tangible diseases, obesity is the root of much psychological distress, which adds to the negative impact of being overweight. As the social pressure to be thin climbs, the number of obese individuals also continues to rise, creating a potentially devastating emotional and physical dilemma for many. Additionally, the overall cost of health care is increased by obesity in this country and in other post-industrialized nations. As health care resources become more limited, then, potentially preventable conditions such as obesity are being pushed into the spotlight of managed care concerns. As a result, many different facets of bariatric medicine have emerged that try to reduce obesity effectively and safely.

Bariatrics is the field of medicine that is concerned with the causes, prevention, and treatment of obesity. Just as cardiac surgeons treat heart conditions, and podiatrists manage diseases of the feet, bariatric physicians are concerned with weight loss. Bariatrics utilizes varied techniques to reduce body fat. Among these are surgical procedures like gastric (or stomach) bypass, cosmetic procedures like liposuction, or pharmaceutical therapies that use drugs to reduce weight. Bariatrics also includes special dieting techniques and exercise regimens, often tailored to meet individual needs. While even a small reduction in weight is known to have beneficial impacts on health, some bariatric methods are controversial because they have significant health risks of their own.

Restriction operations

The surgeries most often used to cause weight loss are restriction operations. Restriction operations limit or restrict food intake by creating a small pouch at the top of the stomach where the food enters from the esophagus. The reduced outlet delays the passage into the stomach and results in a sensation of fullness after eating very little food. The effect is like creating a tiny stomach on top of the existing stomach. The patient, then, perceives only the filling of the tiny stomach. After an operation, the person usually can eat only one half to one whole cup of food without discomfort or nausea. Most people cannot eat normal quantities of food. As a result, patients lose weight.

Restriction operations include gastric banding and vertical banded gastroplasty. Both operations serve only to restrict food intake, maintaining normal digestive processes. In gastric banding, a band made of surgical material restricts food movement near the upper portion of the stomach leaving a small passage for food to enter the rest of the stomach. Vertical banded gastroplasty is more prevalent and uses surgical staples to limit access of food to the stomach. Restrictive operations induce weight loss in nearly all patients. Unfortunately, some patients regain the weight that was lost. Because some patients are unable to modify their eating habits, restriction operations have limited success. Only about 30% of people reach normal weights after vertical banded gastroplasty. However, nearly 80% achieve some degree of weight loss.

Bypass surgery

Gastric bypass operations combine the creation of small stomach pouches to restrict food intake and the construction of paths for food to bypass the small intestine to cause malabsorption, or a lack of adequate nutrient and vitamin absorption into the body. Some gastric bypass surgeries are extensive, involving major portions of the stomach. Because they completely bypass major regions of food absorption, gastric bypass surgeries are more effective in causing weight loss than restrictive operations. Bypass operations generally result in a loss of two-thirds of one's body weight within two years. However, the weight loss comes with severe drawbacks. Because essential vitamins and minerals are obtained from food in the stomach and small intestine, gastric bypass prevents their absorption. Therefore, major vitamin deficiencies can be induced. For instance, anemia may result from insufficient absorption of vitamin B12 and iron. Accordingly, patients are required to take nutritional supplements. Also, the more extensive the bypass operation, the greater is the risk for complications, sometimes requiring the life-long use of special foods and medications.

Liposuction

Lipectomy is the surgical removal of fatty tissue from the body. Liposuction, a specific kind of lipectomy, is the surgical removal of fat from beneath the surface of the skin using suction or vacuum techniques. Most often, it is used to reduce adipose tissue from limited areas of the body, and therefore is considered to be a cosmetic procedure, or one that primarily improves appearance. One method of liposuction in weight control is to inject large volumes of salt water, or saline, containing a local anesthetic into the patient. The solution also contains adrenaline. The anesthetic numbs the procedure area, and the adrenaline constricts blood vessels to minimize bleeding, bruising, and swelling during the procedure. Adipose tissue is then removed by suctioning. Generally, only people who are slightly overweight benefit from liposuction. Because liposuction is surgical, there are some risks involved even though the procedure is considered very safe. While uncommon occurrences, infection, excessive bleeding, and occasional nerve damage can occur.

Drug therapy in bariatrics

Most of the medications that are used in bariatric treatment are appetite suppressants. These pharmaceuticals promote weight loss by decreasing appetite or increasing a sensation of fullness. Often, these medications work by increasing the action of neurotransmitters, substances that nerve cells release to chemically communicate with one another. Two brain neurotransmitters that can affect appetite are serotonin and the catecholamines. Because of their potency and wide physiological effects, most appetite suppressants are approved for short-term use only. An exception is Sibutramine, an appetite suppressant which can be used to treat obese individuals for extended periods of time. In general, appetite suppressant medications used in bariatric treatment have only limited effectiveness. Average weight loss using such medications ranges from 5-22 lb (2.3-10 kg). Some obese individuals, however, may lose up to 10% of their body mass. Amphetamine drugs can result in greater weight reduction, but their use is highly regulated because of their potential for abuse and dependence. In some cases, bariatric physicians will utilize a combination of drugs to maximize weight loss. An example is the concurrent use of fenfluramine and phentermine, called Fen/Phen. Fen/Phen was implicated in a number of serious adverse reactions and is therefore no longer used. (In March 2003, the death of Baltimore Orioles pitcher, Steve Bechler, was linked to use of the diet drug, ephedra.)