Obesity: An Overview What Is the Disease?

Obesity: An Overview

What is the disease?

Obesity is an increasingly prevalent metabolic disorder whereby a patient's BMI or body mass index, defined as the patient's weight in kilograms divided by the patient's height in meters squared in kilograms, is greater than 30. Obesity puts one at greater risk for a number of ailments, and a BMI less than 21 is associated with the greatest protection from coronary heart disease mortality and other life-threatening ailments affecting the heart, other vital organs, and the body's metabolism. (Eckel, 1997)

However, there are problems with the BMI-based definition of obesity, as many women with a BMI of near 30 may be less at risk for heart disease if their increase in adipose tissue is distributed in the pelvis and not the abdomen. Substantial evidence now indicates that an increased waist circumference, or waist-to-hip ratio, better predicts co-morbidities and mortality from obesity, such as heart disease and Type II diabetes better than the strict BMI over 30 definition for obesity. A BMI-based definition of obesity also fails to take body fat distribution into account, or muscle mass in the case of athletes or individuals who engage in powerful muscle mass building activities such as weight training. (Eckel, 1997)

The disease paradigm of obesity is also controversial in the medical community, as doctors tend to think of obesity as a condition brought on by behavior. The idea of treating the condition as a disease is thus unpopular. But Dr. Michael Gonzalez-Campoy thinks obesity should be classified as a disease and treated aggressively like other diseases. "If a patient that's hypertensive walks in and out of an office, they leave with a blood pressure pill. If a patient with obesity comes in, their body mass index is high, and you send them out of the office and you don't treat that obesity -- it would be like sending somebody out with a very high blood pressure and not treating it," because the condition puts one at risk for so many other disorders. (Benson, 2003)

What organs do the disease affect and what are its actions?

Obesity can affect the heart and arteries, as it puts a patient at risk for high blood pressure and hypertension. Increased left ventricular volume and wall stress in addition to increased stroke volume and cardiac output are commonly seen in systemic hypertension in the obese more often than individuals who do not meet the definition. Long-term longitudinal studies, however, indicate that obesity as such not only relates to but independently predicts coronary atherosclerosis. Dilated cardiomyopathies, presumably with concomitant cardiac arrhythmias, may be the most common cause of sudden death in patients with severe obesity.

Metabolically, the condition puts the patient at risk for dyslipidemia, the reduction in HDL (the 'good') cholesterol and elevations in other cholesterol levels. This can cause the additional hardening of the arteries, and impaired glucose tolerance or non-insulin-dependent diabetes mellitus. Insulin resistance and accompanying hyperinsulinemia are typically associated with these co-morbidities. Congestive heart failure and sleep apnea are also risk factors associated with obesity. (Eckel, 1997)