As more and more Americans combine an increase in food consumption with a decrease in physical activity, it is not surprising that there is a growing trend toward overweight and obesity in the United States. The prevalence of obesity has increased from 14.5 to 22.5% in the past 10 to 15 years. In 1998, 97 million American adults, representing 55% of the population, were designated as being overweight or obese. With the obese population in the United States continuing to rise, it becomes evident that obesity and obesity-related disorders will be encountered more frequently in the health-care industry.
On the basis of guidelines released by the National Institutes of Health, a person with a body mass index (BMI) of 25 to 29.9 is defined as overweight, whereas obesity is defined as having a BMI of >30Л In addition to psychological and social difficulties faced by people who are categorized as obese, they are more susceptible to physiologic complications and having decreased length of life.
Many studies concur that as BMI increases, so does the risk of mortality. The overall mortality is approximately twice as high in the severely obese and may be 2 to 25 times higher than normal in disease-specific mortality. In addition, obesity increases the risk of cardiovascular disease, noninsulin-dependent diabetes mellitus, hypertension, respiratory dysfunction, and certain types of cancer. Obese patients undergo more frequent hospitalizations because obesity exacerbates the onset and progression of illnesses. Although many hospitalized patients pass through the ICU at some time during their stay, it is expected that the number of obese patients requiring intensive care will also increase substantially. There are several studies that do not concur that BMI correlates with mortality; however, this is normally a result of smaller populations. In larger populations, the significant association is shown. This study examines the effect of BMI on the outcome of patients in a medical ICU (MICU).