Bulimia Nervosa

The term bulimia is derived from the Greek word for ox hunger and depicts the extreme nature of binge eating. Cases of bulimia nervosa, which is characterized by binge eating and purging, were not reported until the 1970s.30 Purging behavior may include induced vomiting by ipecac or other means, or abuse of laxatives, enemas, diuretics, caffeine, or other stimulants.1 However, it is more difficult to recognize than anorexia because individuals with bulimia nervosa exhibit no signs of illness and most are of normal weight. Studen-Pavlovich and Elliott relate that “normal weight is the most distinguishing characteristic in differentiating anorexia nervosa from bulimia nervosa.”31

According to the Diagnostic and Statistical Manual of Mental Disorders, binge eating and other behaviors must occur at least twice a week for a period of three months to qualify for the diagnosis of bulimia. Table I presents the diagnostic criteria for bulimia.

The prevalence of bulimia among women is 1 to 3% while the rate of occurrence among men is 0.1%. The risk for bulimia is associated with age, gender, and race. Most cases occur in late adolescence or early adult years with the median age of onset at 18 years. Cases of bulimia typically occur in industrialized countries where food is plentiful and a preoccupation with thinness in women is apparent.31,32

The binge and purge cycle characteristic of bulimia can affect multiple organ systems resulting in a variety of medical complications. Overeating associated with binge episodes can stretch the stomach or delay gastric emptying. Purging can induce esophagitis, gastroesophageal reflux disease, or esophageal rupturing.32,33 Pancreatitis and renal function impairment may occur. Protein malnutrition, dehydration, and electrolyte imbalances can occur leading to hypokalemia and hypochloremia, muscle cramping, weakness, dizziness, excessive thirst, parasthesia, and syncope.34 Bruises, calluses, scarring, and abrasions of the fingers may be present, reflecting excessive induced vomiting behaviors. In severe cases, cardiovascular abnormalities can result in arrhythmias, arrest, cardiac rupture, or pneumomediastinum.32

The etiology of bulimia has been associated with genetic, physiological, psychological, and environmental
factors. Several hypotheses exist concerning a physiologic explanation for bulimia, suggesting specific chemical abnormalities in the body. One hypothesis involves abnormalities of serotonergic function. Serotonin is involved in the development of satiety. It is believed to increase postprandial satiety rather than directly decreasing appetite. Disturbances in serotonergic function or low levels of serotonin may be responsible for blunting the sensation of satiety and prolonging periods of food ingestion. Another possible pathophysiology involves the presence of increased levels of peptides, specifically, pancreatic polypeptide PYY, known to increase appetite. Increased levels of PYY have been found in some individuals with bulimia.32

Both obesity and a history of dieting are risk factors for bulimia. Individuals with bulimia have eating binges during or immediately following a diet. Psychological factors and family history of eating disorders also appear to be related to the development of bulimia. Depression, affective disorders, anxiety disorders, substance abuse, and a history of sexual abuse may increase the chances of developing bulimia.21,32

Like individuals with anorexia, athletes and models are thought to be at risk for developing bulimia. These individuals are often placed in front of crowds and judges, which may lead to a preoccupation with weight and body image.

Assessment and diagnosis of bulimia may be difficult given that many individuals with this condition appear to be of normal weight and tend to avoid disclosing their bingeing and purging behaviors. Furthermore, there is no specific laboratory study that will diagnose bulimia. A screening tool that is used in the United Kingdom on individuals suspected of having bulimia appears in Table IV. The five items, called the SCOFF (sick, control, one, fat, food) questionnaire, are designed to identify key features of anorexia and bulimia. Morena states that the falsepositive rate is 12.5% and that the sensitivity rate is very high.32 One point is awarded for each “yes” response. A score greater than two indicates a likely case of anorexia or bulimia.

In suspected cases of bulimia, a body chemistry panel may be used to determine if electrolyte imbalances are present. A cardiac assessment is warranted for individuals who use ipecac to purge. Electromyography should be considered if abuse of ipecac is suspected, or the individual has symptoms suggesting hypokalemia or arrhythmias. Gastric motility studies are recommended for individuals with a prolonged history of bulimia, a history of constipation, or other unexplained abdominal pain.