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Disorders of Nutritional Status

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such as amenorrhea, and low bone density, 53 does not meet the strict DSM-5 criteria for anorexia nervosa or bulimia nervosa, but shares many of the characteristics and therapeutic concerns (see Chapter 44). Persons with eating disorders may require concomitant evaluation for psychiatric illness because eating disorders often are accompanied by mood, anxiety, and personality disorders. Anorexia Nervosa Anorexia nervosa is an eating disorder that usually begins in adolescence and is characterized by deter- mined dieting, often accompanied by compulsive exer- cise and, in a subgroup of persons, purging behavior with or without binge eating, resulting in sustained low weight. 54 Other features include a disturbed body image, a pervasive fear of becoming obese, and obsession with severely restricted caloric intake. The causes of anorexia appear to be multifactorial, with determinants that include genetic influence, person- ality traits of perfectionism and compulsiveness, anxi- ety disorders, family history of depression and obesity, and peer, familial, and cultural pressures with respect to appearance. 54 Other psychiatric disorders often coexist with anorexia nervosa, including major depression or dysthymia and obsessive–compulsive disorder. Many organ systems are affected by the malnutri- tion that occurs in persons with anorexia nervosa. The severity of the abnormalities tends to be related to the degree of malnutrition and is reversed by refeeding. The most frequent complication of anorexia is amen- orrhea and loss of secondary sex characteristics with decreased levels of estrogen, which can eventually lead to osteoporosis. Bone loss can occur in young women after as short a period of illness as 6 months. 48 Symptomatic compression fractures and kyphosis have been reported. Constipation, cold intolerance and failure to shiver in cold, bradycardia, hypotension, decreased heart size, electrocardiographic changes, blood and electrolyte abnormalities, and skin with lanugo (i.e., increased amounts of fine hair) are common. Abnormalities in cognitive function may also occur. The brain loses both white and gray matter during severe weight loss; weight restoration results in return of white matter, but some loss of gray matter may persist. 54 Unexpected sudden deaths have been reported; the risk appears to increase as weight drops to less than 35% to 40% of ideal weight. It is believed that these deaths are caused by myocardial degeneration and heart failure rather than arrhythmias. The most exasperating aspect of the treatment of anorexia is the inability of the person with anorexia to recognize there is a problem. Because anorexia is a form of starvation, it can lead to death if left untreated. A multidisciplinary approach appears to be the most effective method of treating persons with the disorder. The goals of treatment are eating and weight gain, and efforts to work on psychological, relationship, and emo- tional issues. Adults whose weight is more than 25% below the expected weight (or with less weight loss if there are coexisting medical or psychiatric conditions,

or both) and children or adolescents who are losing weight rapidly generally require hospitalization to ensure an adequate food intake and to limit physical activity. 54 Bulimia Nervosa Bulimia nervosa is defined by recurrent binge eating and activities including vomiting, fasting, excessive exercise, and use of diuretics, laxatives, or enemas to compensate for that behavior. Bulimia nervosa usually begins during adolescence, with a peak period of onset around 18 years of age. 55 In contrast to anorexia ner- vosa, which is characterized by a weight that is less than 85% of normal, most persons with bulimia ner- vosa are of normal weight. The disorder may be asso- ciated with other psychiatric disorders such as anxiety disorder or depression. There is also an association with substance abuse and risky and self-destructive behaviors. 55 The complications of bulimia nervosa include those resulting from overeating, self-induced vomiting, and cathartic and diuretic abuse. 55–57 Among the compli- cations of self-induced vomiting are dental disorders, parotitis, and fluid and electrolyte disorders. Dental abnormalities, such as sensitive teeth, increased den- tal caries, and periodontal disease, occur with frequent vomiting because the high acid content of the vomitus causes tooth enamel to dissolve. Esophagitis, dyspha- gia, and esophageal stricture are common. With fre- quent vomiting, there often is reflux of gastric contents into the lower esophagus because of relaxation of the lower esophageal sphincter. Vomiting may lead to aspi- ration pneumonia, especially in intoxicated or debili- tated persons. Potassium, chloride, and hydrogen are lost in the vomitus, and frequent vomiting predisposes to metabolic acidosis with hypokalemia (see Chapter 8). An unexplained physical response to vomiting is the development of benign, painless parotid gland enlargement. The weights of persons with bulimia nervosa may fluctuate, although not to the dangerously low levels seen in anorexia nervosa. Their thoughts and feelings range from fear of not being able to stop eating to a con- cern about gaining too much weight. They also experi- ence feelings of sadness, anger, guilt, shame, and low self-esteem. Treatment strategies include psychological and pharmacologic treatments. Cognitive-behavioral ther- apy is the psychosocial therapy predominately used. 56 This therapy is designed to help individuals become aware of other ways to cope with the feelings that precipitate the desire to purge and to try and correct maladaptive beliefs regarding their self-image. Unlike persons with anorexia nervosa, persons with bulimia nervosa are upset by the behaviors practiced and the thoughts and feelings experienced, and they are more willing to accept help. Pharmacotherapeutic agents include the tricyclic antidepressants, the selective sero- tonin reuptake inhibitors, and other antidepressant medications. 55