Morbid Obesity

Morbid Obesity is a condition that affects as much as 10% of the American population. Though there is no direct cause, there may be several contributing factors. The morbidly obese are subject to greatly increased risk of sudden death due to heart attack and stroke. Additionally, they usually have several concomitant health problems made worse or caused by their obesity. The social stigma of their obesity often makes it difficult for these people to find employment or a spouse. Most of these patients do indeed wish to lose weight but consistently fail to do so with dieting. The image of the jolly fat person is greatly over exaggerated. Most of these people are extremely unhappy with their obesity, and even when they achieve only modest weight loss, they experience a remarkable improvement in self-image.

Several different methods have been utilized to define who is morbidly obese. Many of the older nomograms and definitions of ideal body weigh were very unfair to those who have larger skeletal frames and were not obese, yet by these old definitions they would have been defined as such. The most useful index for estimating excess body fat is the body mass index.   This is simply the nude weight of an individual measured in kilograms, divided by the square of the barefoot height of that individual in meters. (Kg/m2) This parameter is also very useful because it standardizes both men and women. Thus, an individual with a BMI of greater than 25 is considered overweight, over 30 obese, and over 40 morbidly obese.

As stated above, the morbidly obese have a much greater incidence of sudden death due to heart attack and stroke, and a much higher incidence of other medical problems, which may lead to a shortened life expectancy. Each of these associated medical conditions will be discussed briefly.

Hypertension is prevalent among the morbidly obese population. Over a period of time this places stress on the heart and vascular system and is known to decrease life expectancy. Weight loss will correct or improve hypertension in many, though not all, morbidly obese patients.

Obesity is a frequent cause of adult onset diabetes mellitus. In fact, diabetes is present in as many as one half of the obese population. Many of these patients require oral medications or insulin to control their blood sugars. Long standing diabetes is known to cause or exacerbate cardiovascular disease, and also leads to many other problems including kidney disease, blindness, skin ulcers that do not heal, just to name a few. Diabetes in morbidly obese patients may be very difficult to control with medications. Following significant weight loss, many of these patients are no longer diabetic or are at least much easier to control.

Atherosclerosis occurs at an earlier age in morbidly obese patients and in combination with diabetes, hypertension, and the added stress on the heart due to obesity, results in a higher incidence of stroke and myocardial infarction (heart attack). This may be due, in part, to the fact that morbidly obese patients have a higher incidence of hyperlipidemia with increased circulating fats and cholesterol resulting in atherosclerosis. Though weight loss does not reverse atherosclerosis, it may slow its progression.

Many morbidly obese patients experience phenomena such as pulmonary emboli, deep venous thrombosis due to hypercoagulability. These patients have abnormally low levels of a serum protein called antithrombin III, which is normally responsible for inhibiting clot formation in the general circulation. Their blood clots more easily than normal resulting in blood clots in the legs that may then travel to the lungs. Additionally, their body weight causes increased pressure in the veins in the legs resulting in varicose veins and venous stasis, or poor venous circulation. All of these contribute to increase the likelihood of blood clot formation. Additionally, this increased venous pressure is transmitted to the tissues and skin of the leg and may result in skin breakdown and ulceration. These ulcers can be notoriously difficult to heal. All of these may improve drastically with weight loss.

Severe pulmonary dysfunction is associated with morbid obesity. Many of these patients cannot expand their lungs normally during respiration and thus experience restrictive pulmonary disease. Additionally, there may be an obstructive component caused by anatomical abnormalities in the upper airways due do their obesity. This produces sleep apnea in which the patient cannot breathe during sleep. This causes them to be awakened constantly during the night each time their airway closes. Most of these patients suffer during the day from not getting enough sleep. The incidence of motor vehicle accidents in sleep apnea patients is alarmingly high. The improvement in these types of symptoms following weight reduction is dramatic.

Necrotizing Fasciitis is a rapidly spreading infection of the soft tissues, which is caused by a variety of different bacteria. Since fat has relatively poor blood supply, it makes an excellent medium for propagation of this type of infection. Markedly obese patients often have mild skin infections in the dependent areas of the abdominal wall and groins, which may invade the deeper soft tissues and develop into this severe life threatening infection. These infections often occur in the presence of diabetes, which as already stated is prevalent in the obese population.

Degenerative arthritis affects the morbidly obese with great frequency and at an early age. This is largely due to the enormous strain placed on the hip and knee joints by the excessive weight they are required to bear. Joint replacement surgery in these patients is doomed to early failure since the prosthetic joints as well are not designed to bear this much weight for long periods of time. This condition can result in severe disability or incapacity.

Cholelithiasis, or gallstones, is prevalent in 30% or more of obese patients. In contrast, gallstones are present in about 10% of the general population. The increased incidence of gallstones in the obese is probably due to dietary factors. All operations for the purposes of inducing weight loss increase the likelihood of gallstone formation, at least early in the post-operative period. For this reason, many surgeons advocate removing the gallbladder at the time of obesity surgery, at least in those patients who have gallstones.

On occasion, obese patients are encountered who suffer daily incapacitating headaches. They are often found to have evidence of increased intra-cranial pressure on physical exam, CT and lumbar puncture. This condition is known as pseudotumor cerebri. The cause is not known but probably has to do with impairment of normal absorption of cerebrospinal fluid. Generally, these symptoms respond impressively to weight reduction.

Many obese patients suffer from various forms of psychosocial impairment. Depression is common among the morbidly obese. They often have difficulty attracting members of the opposite sex or in obtaining employment that requires them to interact with other people. The debility they suffer due to many of the conditions described above, may also make it difficult for them to find employment or to advance in position if they are employed. This all leads to severe impairment of self-image, which often leaves them reclusive. Interestingly, following weight reduction of even moderate amounts, many of these psychosocial factors show dramatic improvement.

The human species is designed to store fat for periods of starvation, which were common during human evolution. In modern society, where food is plentiful, particularly low quality "junk" food, being overweight is common. Nevertheless, the human brain tells the individual when "enough is enough", thus most people do not eat to the point of becoming morbidly obese. It is not known what causes a person to become morbidly obese. There are several medical conditions that can lead to extreme weight gain, particularly endocrine dysfunction of the adrenal glands or thyroid. However, most of these patients have no such underlying pathology. Several theories have been postulated regarding control of hunger in the hypothalamus. Research in this area is ongoing, but as of yet there are no clear answers. In many cases, obesity runs in families, which may suggest a genetic predisposition, but may simply be due to common environmental influences likely to be present in a family.

Losing weight, particularly of the magnitude required for the morbidly obese is extremely difficult. We all know the kind of sacrifice it takes to lose that extra 10 or 20 pounds that many of us carry around periodically. It is a fight against 2 million years of evolution that has made it possible to survive in extreme conditions where food is scarce. Moreover, once one has lost the weight, keeping it off is even more difficult. This is largely due to the fact that the number of fat cells in our bodies is constant and set at a very early age. When we lose weight, the amount of fat per cell decreases but the number of fat cells does not. Each of these fat cells then "craves" fat to be stored within it. Maintenance of weight loss requires major modifications of life style. One must eat less and of better quality. In addition, exercise, even of moderate nature, is essential to weight control. No diet, pill or operation can induce long-term weight reduction if behavior modification is not part of the program.

A patient seeking weight loss through surgery must expect to first undergo a series of diagnostic tests to rule out underlying metabolic problems that may be causing or contributing to their obesity. If any are found, they of course, must be corrected. Generally, they also undergo psychological testing to assure that there are no major psychiatric disturbances that may interfere with a patient's ability to follow a long-term treatment regimen. Other tests to assess pulmonary and cardiac function may also be warranted.

Prior to undertaking surgery for weight loss, a controlled, observed trial of dieting, behavior modification, and medications may also be employed. In spite of these interventions, even when stalwartly adhered to, long-term significant weight control is often difficult if not impossible in morbidly obese patients. Surgery may be the last hope for many of these patients but is often the most successful at achieving the desired result.

Typically, by 18 months after surgery, most patients have lost about 80% of excess body weight, with the most rapid weight loss occurring in the first 6 months. For example, a 5'8" person weighing 263 pounds (BMI = 40) undergoing gastric bypass could expect to lose about 78 pounds over 18 months with a resulting weight of about 184 lbs or about 20 lbs over ideal body weight. A 5'8" person weighing 350 lbs could expect to lose about 148 lbs but would still weigh 202 lbs. This effect is more magnified with greater starting weight. Nevertheless, the physiologic and emotional benefits of this weight loss are extraordinary even though the end result of achieving ideal body weight is never accomplished.

Prior to considering surgery for morbid obesity one must consider the potential risks. The most feared risk of gastric bypass is leak at the anastamosis between the stomach and the intestine. Fortunately, this occurs with a low frequency. Morbidly obese patients have an increased risk of other post-surgical complications including wound infections, pulmonary embolism and pneumonia to name a few. Many interventions are done to minimize the risk of these complications, however, the increased risk is related to the morbidly obese status of these patients. All considered, the risk of being morbidly obese far outweighs the risk of surgery and the benefits of weight loss are enormous.

For yet more information, please visit my website, Pascack Valley Surgical Associates.

For a more detailed description of the surgery and typical post-surgical management of Morbid Obesity, please visit the section on Laparoscopic Morbid Obesity Surgery.

John L Holup, DO email