DEFINITION
An eating disorder marked by an intense fear of gaining weight, a refusal to maintain a healthy weight, and a distorted body image. People with anorexia nervosa have an abnormal loss of appetite for food, try to avoid eating, and eat as little as possible.
EPIDEMIOLOGY
Anorexia usually begins during the teen years or young adulthood (13-20). It is more common in females, but may also be seen in males. The disorder is seen mainly in white women who are high academic achievers and who have a goal-oriented family or personality. Among the psychiatric disease, the nervous anorexia has higher mortality, which varies in different series between 4 and 20%, being linked in a quarter of cases to suicide and in most of the other complications of severe malnutrition.
SYMPTOMPS
To be diagnosed with anorexia, a person must:
• Have an intense fear of gaining weight or becoming fat, even when she is underweight
• Refuse to keep weight at what is considered normal for her age and height (15% or more below the normal weight)
• Have a body image that is very distorted, be very focused on body weight or shape, and refuse to admit the seriousness of weight loss
• Have not had a period for three or more cycles (in women)
People with anorexia may severely limit the amount of food they eat, or eat and then make themselves throw up. Other behaviors include:
• Cutting food into small pieces or moving them around the plate instead of eating
• Exercising all the time, even when the weather is bad, they are hurt, or their schedule is busy
• Going to the bathroom right after meals
• Refusing to eat around other people
• Using pills to make themselves urinate (water pills or diuretics), have a bowel movement (enemas and laxatives), or decrease their appetite (diet pills)
Other symptoms of anorexia may include:
• Yellow skin that is dry and covered with fine hair
• Confused or slow thinking, along with poor memory or judgment
• Depression
• Dry mouth
• Extreme sensitivity to cold (wearing several layers of clothing to stay warm)
• Loss of bone strength
• Wasting away of muscle and loss of body fat
Complications may include:
• Bone weakening
• Decrease in white blood cells, which leads to increased risk of infection
• Low potassium levels in the blood, which may cause dangerous heart rhythms
• Severe dehydration
• Severe malnutrition
• Seizures due to fluid or sodium loss from repeated diarrhea or vomiting
• Thyroid gland problems
• Tooth decay
PATHOGENESIS
Anorexia nervosa is associated with endocrine abnormalities as the hypothalamic amenorrhea, that is main diagnostic criteria of this psychiatric illness. This condition may persist after normalization of weight, while others endocrine complications of anorexia nervosa disappear with weight recovery. Recently has been shown that some peptides involved in the control of feeding behaviour (Leptin, Ghrelin) are altered in anorexia nervosa.
Leptin
In 1994 has been identified a new gene ob that encodes a 16kD protein called Leptin (from Greek leptòs, slim and thin)
Leptin is a protein hormone produced by white adipose tissue, but also by other tissues including some pituitary cell lines (somatotroph, thyrotropic and gonadotropic). This peptide has a key role in the control of body weight, because it reduces the caloric intake and increase energy expenditure at rest, through central action mediated by the inhibition of neuropeptide Y (NPY, stimulant food intake) and by stimulation of proopiomelanocortin (POMC, important mediator of the anorectic effects of Leptin itself) through JAK/STAT via.
Leptin induces puberty and increases fertility, stimulating GnRH release from arcuate nucleus neurons.
The circulating levels of the hormone are correlated with the fat reserves and they are high in diseases characterized by accumulation of body fat such as obesity. Instead, Leptin is reduced in a disease characterized by extreme thinness as anorexia nervosa.
Leptin may contribute to the difficulty of gain weight, in fact, recent data seem to show that patients, who have high Leptin concentrations, have risk of relapse of weight loss within one year.
Ghrelin
Ghrelin is a peptide produced by stomach, hypothalamus and pituitary gland. It acts to stimulate appetite and its secretion is decreased by ingestion of nutrients and increases before eating. It regulates food intake by binding specific receptors in the arcuate nucleus: in this way activates neurons that produce NPY to stimulate feeding .
Serotonin
Serotonin dysregulation: particularly high levels in the brain with the5HT1A receptor – a system particularly linked to anxiety, mood and impulse control. Starvation has been hypothesized to be a response to these effects, as it is known to lower tryptophan and steroid hormone metabolism, which might reduce serotonin levels at these critical sites and ward off anxiety. Other studies of the 5HT2A serotonin receptor (linked to regulation of feeding, mood, and anxiety), suggest that serotonin activity is decreased at these sites.
EXAMS AND TESTS
Tests should be done to help find the cause of weight loss, or see what damage the weight loss has caused. Many of these tests will be repeated over time to monitor the patient.
These tests may include:
• Albumin
• Bone density test to check for thin bones (osteoporosis)
• CBC
• Electrolytes
• Kidney function tests
• Liver function tests
• Total protein
• Urinalysis
TREATMENT
The biggest challenge in treating anorexia nervosa is helping the person recognize that he or she has an illness. Most people with anorexia deny that they have an eating disorder. People often enter treatment only once their condition is serious. The goals of treatment are to restore normal body weight and eating habits. A weight gain of 1 - 3 pounds per week is considered a safe goal.
A longer hospital stay may be needed if:
• The person has lost a lot of weight (being below 70% of their ideal body weight for their age and height). For severe and life-threatening malnutrition, the person may need to be fed through a vein or stomach tube.
• Weight loss continues even with treatment
• Medical complications, such as heart problems, confusion, or low potassium levels develop
• The person has severe depression or thinks about committing suicide
Different kinds of talk therapy are used to treat people with anorexia: the goal of therapy is to change patients' thoughts or behavior to encourage them to eat in a healthier way. This kind of therapy is more useful for treating younger patients who have not had anorexia for a long time.
Medications such as antidepressants, antipsychotics, and mood stabilizers may help some anorexic patients when given as part of a complete treatment program. Examples include:
• Antidepressants, especially selective serotonin reuptake inhibitors (SSRIs)
• Olanzapine (Zyprexa, Zydis) or other antipsychotics
These medicines can help treat depression or anxiety.
Although these drugs may help, no medication has been proven to decrease the desire to lose weight.
Anorexia nervosa
Anorexia nervosa
