As one’s weight increases, so do the risks for many diseases linked to obesity:

• Heart disease
• Pulmonary disease
• Diabetes
• Bone and joint pains
• Certain types of cancer

The U.S. Public Health Service’s health indicator list recognizes obesity as a serious public-health problem. Obesity now rivals tobacco use as one of the top conditions leading to increased health problems.

Among the most significant health consequences of obesity are

• Death and sudden death
• Hypertension and heart disease
• Type 2 diabetes
• Obstructive sleep apnea
• Gallstones
• Cancer
• Other complications, including arthritis and depression

Death and Sudden Death

More than 400,000 annual deaths are attributable to obesity in the United States. There is a direct association between the degree of obesity and medical problems, with an exponentially increased risk of death from comorbid conditions as the body mass index (BMI) increases.

• A Veterans Administration study of 200 morbidly obese men found a twelve-fold increase in death in patients between the ages of 25 and 34, a fivefold increase between the ages of 35 and 44, a threefold increase between 45 and 54, and a twofold increase in those above 54 years of age, compared to men of normal weight.
• The Framingham Study related morbid obesity to a progressively higher incidence of sudden death. If a patient developed respiratory distress requiring supplemental oxygen or a tracheostomy, the mortality exceeded 30 percent.
• At the 2004 American Surgical Association Meeting, investigators from McGill University presented results from a comparison of medical care of 5,746 morbidly obese patients matched six to one with 1,035 morbidly obese patients who underwent gastric bypass surgery. The matching was based on sex, age, and duration and degree of obesity.
  
  The average BMI for medically managed patients was 40 and for the surgical patients it was 50. Five-year mortality was reported as 6.17 percent in the medically managed group compared to only 0.68 percent in patients who underwent surgery. This is a ten-fold increased risk of dying without surgery.
  
  The different outcomes were even more startling when the health status of survivors was reviewed as the medically managed patients still were morbidly obese and suffered from the same medical problems, while the surgically managed group had lost over 100 pounds and were relieved of most of their obesity-related illnesses.
  
  The improved health status was reflected in the total health care costs for the two groups over the five-year period. The total cost for medications, hospitalizations, and physician office visits was 34.5 percent lower in the surgical group. They concluded that not only were health care benefits remarkable, the cost of surgical intervention was recovered in just 3.5 years. Thereafter, the health care system saved money.

Hypertension and Heart Disease

There is a threefold increased incidence of high blood pressure in the morbidly obese patient with an increased incidence of heart disease and stroke. A weight reduction of as little as 4.5 kg has been shown to reduce blood pressure in most overweight persons with hypertension.

Furthermore, small reductions in weight have demonstrated an improvement in ventricular function and oxygenation in patients with congestive heart failure, whereas larger weight losses, as those seen with gastrointestinal surgery for obesity, reduce cardiovascular mortality.

Type 2 Diabetes

The Nurses’ Health Study demonstrated a fourfold increased risk for type 2 diabetes mellitus in women with a BMI between 23.0 and 25.0 kg/m² compared with women with a normal BMI. Women with a BMI greater than 35.0 were over 93 times more at risk of developing the disease. The study also demonstrated that weight gain during adulthood increased the risk for type 2 diabetes mellitus and importantly, weight loss reduced this risk by an average of 50 percent in those who lose as little as 5.0 kg. For individuals who already have type 2 diabetes mellitus, weight loss improved the severity of the disease by reducing hyperglycemia and hyperinsulinemia.

Obstructive Sleep Apnea

The incidence of sleep apnea in severely or morbidly obese patients that requires therapeutic intervention approaches 40 percent in men and 3 percent in women. Strollo and Rogers documented a relationship between the presence of sleep apnea and hypertension, nocturnal dysrhythmias, pulmonary hypertension, right and left ventricular heart failure, myocardial infarction, and stroke. Weight reduction can significantly improve both the oxygen desaturation index and blood pressure and improve survival.

Gallstones

The risk of gallstones increases with increasing BMI. In women, the risk of either gallstones or cholecystectomy is about 20 per 1,000 women per year for a BMI greater than 40 compared with three per 1,000 in normal weight women. Contrary to the other comorbid conditions, weight reduction in the morbidly obese patient increases the risk of gallstone formation, especially if the weight loss is rapid.

Cancer

The incidence of several cancers are now known to increase with increases in body mass index, including breast cancer in postmenopausal women, endometrial cancer, prostate cancer in men, and colon cancer in both sexes.

Other Complications

Crippling arthritis and aggravation of prior joint injuries is a common condition, sometimes restricting the ability to work. Additionally, morbidly obese patients suffer real psychological stresses with limited access to public conveniences, ridicule, prejudice on the job, and limitation of social activities. The suicide rate among these patients is greater than that of the normal population with nearly a tenfold incidence of depression.

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