Medical Impact of Obesity
People who are obese have higher rates of medical problems. Once this process reaches the level of “morbid obesity”, defined as a BMI of greater than 40, then the weight causes progressive and extensive damage to the body. With this comes an extensive list of medical problems (or co-morbidities), with an associated shorter life expectancy. Every five unit increase above (the most healthy) BMI of 25 translates into a 40% increase in death from heart disease and a 10% increase in cancer death.
This results in a four-fold increase in cardiac death and two-fold increase in cancer death. For those with morbid obesity, life expectancy averages ten years less than normal. Indeed, the collective risk of premature death of Americans with a BMI greater than 40 is 6-12 fold that of the non-obese population (see Obesity In America).
Further, early death is only one potential consequence. The social, economic and psychological effects of obesity are real and are especially devastating. Studies show that those with morbid obesity are looked upon with disdain and prejudice. Not only considered less attractive, but also less motivated and intelligent. Studies show blunted opportunity for advancement and lesser earning potential in the workplace as well as increased strain on personal relationships. Obese persons clearly represent one of the last people groups in the U.S. to suffer open, accepted bias.
So for most, morbid obesity leads to a shorter, unhealthier and less satisfying life – a truly devastating disease.
Comorbidities of Obesity
Severe obesity causes damage to nearly every body system. Below are some of the serious medical conditions (called comorbidities) for each organ system commonly associated with this problem. These comorbid conditions are what make morbid obesity a disease in and of itself. One key thing to note is that much of this damage will be stopped or even reversed with significant weight loss.
Type II Diabetes (400% higher risk occurrence)
This is by far the most devastating of comorbidities, seen in approximately 30% for those with severe obesity. Obese individuals develop a resistance to insulin. The resulting high blood sugar levels causes serious damage to the body over time. The majority of diabetics are obese, and it affects nearly every body system, increasing the risk of heart disease, kidney failure, nerve damage, eye complications and foot problems, as well as increased risk of infection.
This includes heart disease (300% increased risk) and high blood pressure (210% increased risk). These related problems also affect multiple body systems resulting in a variety of conditions such as heart attacks, anginas, arrhythmias, stroke, kidney damage and artherosclerotic vascular disease.
This refers to elevated cholesterol and triglycerides in the blood. These substances are deposited in the arteries, further leading to vascular damage. This increases the risk of stroke, heart attack and peripheral vascular disease.
Two distinct respiratory problems can occur with obesity. The more common is Obstructive Sleep Apnea, which occurs from excessive soft tissue surrounding the air way. This causes airway collapse when asleep, resulting in long breathing pauses when asleep. This can result in hypoxic cardiac arrest and sudden death. At best, it causes severe daytime fatigue from the lack of restful sleep. A less common but more serious problem is obesity hypoventilation syndrome (Pickwickian syndrome). This is a restrictive lung disease from increased pressure on the thoracic cage. Ultimately, this can lead to pulmonary hypertension and irreversible heart failure.
Acid reflux has increased 300% in the last 30 years parallel to the increase in obesity rates. Over time, this can damage the esophagus causing a pre-malignant condition called Barrett’s esophagus. This condition occurs in about 10-15% of those with GERD, markedly increasing the risk of esophageal cancer. Indeed, cancer of the esophagus is the fastest growing cancer in U.S. history, increasing 750% over the last 40 years. Only 12% of those with this cancer survive over five years. GERD can not only be an uncomfortable and persistent problem, but can actually become a life threatening issue.
Increased abdominal pressure causes poor venous return from the legs. This causes leg swelling and can lead to cellulitis (infection) and leg ulcers. More important, this significantly increases the risk of deep vein thrombosis (blood clots) and possible pulmonary embolism, a fairly common cause of sudden death in the severely obese. So just as with GERD, venous problems can be much more than a nuisance but produce a life threating complication.
In 2001, the National Cancer Institute concluded that several cancers are associated with obesity: colon, breast, endometrial, kidney and esophageal cancer are all increased several fold. Obesity has been said to account for up to 20% of all cancer deaths. Further, death from all cancers, stage for stage, is 50-60% higher for those with severe obesity. This risk has been shown to normalize with weight loss.
The increased stress on weight bearing joints causes degenerative changes that are largely irreversible. This is a nearly universal problem for those with severe obesity over 30 years old. Although not life threatening, it is probably the most debilitating of comorbidities associated with obesity. Further, joint pain is often markedly improved with even moderate weight loss. In addition, joint replacement, if indicated, becomes a viable option, as it is contraindicated with those suffering morbid obesity.
Female Reproductive Dysfunction
Excess adiposity causes marked hormonal imbalance resulting in a variety of issues. This is because the adipose cell creates an estrogen like compound that “confuses” the reproductive system. The “unopposed estrogen” causes problems such as infertility, menstrual irregularity, polycystic ovarian syndrome, and hirsutism (male characteristics). These issues are almost universally reversed with weight loss.
Increased abdominal pressure will easily overcome the relatively weak sphincter muscle below the female bladder. As a result, it is very common for obese women to leak urine involuntarily, during sneezing, laughing or exercise. Though not life threatening, it is an embarrassing and sometimes overwhelming problem.
This is often called a “fatty liver”. It can be a silent but deadly problem. It is seen in about 60% of those with severe obesity, and is the most common cause of cirrhosis (liver failure) in non-alcoholics. Up to 10% may develop liver failure. However, it is also shown to improve with weight loss.
Also called benign intracranial hypertension, it is characterized by increased intracranial pressure. Symptoms include headache, buzzing around the ears, dizziness, and nausea. It ultimately can cause vision loss. Notably, it is seen almost exclusively in young, obese females and universally resolves with weight loss.
Although there is not a higher incidence of mental illness in the morbidly obese population, the incidence of depression is as high as 25%. Severe obesity presents constant challenges: repeated failure with dieting, social rejection, as well as discrimination at work or even from health care providers. For this reason, weight loss is associated with significant, albeit not universal improvement in this comorbidity.
Additionally, a variety of medical problems and ailments, although not included above, have been shown improve significantly with weight loss. These include: Migraines, hypothyroidism, gout, sexual dysfunction, IBS, chronic skin infections.