Eating Disorders in Adolescents: Bulimia Nervosa & Anorexia Nervosa

00:01 In this lecture, we will review eating disorders. Let’s talk about the general characteristics of eating disorders. Generally, these are disorders where patients have abnormal eating habits or they have insufficient or excessive food intake. In general, because they are disorders, this eating habit is detrimental to the patient’s mental and physical health. The peak onset of eating disorders is generally during puberty and late teen years. Girls are 2 to 2 ½ times more likely to have an eating disorder than boys. When we look at eating disorders, we generally break them down into two major categories. Anorexia nervosa which is a limitation of food intake occurs in roughly 0.5% of adolescents, whereas bulimia nervosa happens in about 3%.

00:58 So, there are many potential causes of eating disorders. Certainly, there are socio-cultural causes such as media influence on excessive need to be thin, cultural norms, excessively emphasizing thinness will impact adolescents. Also however, there are biologic or genetic predispositions to patients with eating disorders. Interpersonal relationships may affect an adolescent’s eating disorder.

01:27 Psychological factors such as low self-esteem, perfectionism, impulsivity, or obsessive-compulsive disorder or obsessive-compulsive traits may predispose an adolescent girl to being a patient with an eating disorder. Sometimes when the environment is particularly challenging for an adolescent, they may use an eating disorder as a faulty mechanism for feeling in control of their lives.

01:54 Let’s start with bulimia nervosa. Bulimia is a disease which is characterized by recurrent episodes of binge eating. This means they eat a large amount of food more than most people would eat in one sitting. They may have a sense of a lack of control, overeating during the episode.

02:17 They just can’t control themselves. They keep eating more and more. Then there is a recurrent inappropriate compensatory behavior in order to prevent the weight gain that would necessarily happen if the patient continued to binge. This generally happens twice a week for three months.

02:37 So, if we see someone with twice a week inappropriate compensatory activity, we may be concerned that they have bulimia. Patients may engage in self-evaluation influenced by body shape or weight.

02:57 They’ll check their weight. Check how things are going. These episodes are not exclusively during periods of anorexia. Anorexia nervosa on the other hand is when adolescents, usually girls refuse to maintain a normal body weight. They’ll generally have a body weight that is less than 85% of their ideal body weight for their age and their height. These patients may have an intense fear of gaining weight. They also may have a disturbance in their own perception of their weight or shape.

03:33 They may be very thin and think they are not very thin. Additionally, we frequently see these patients as presenting with secondary amenorrhea. So there are a number of questions we need to ask in an adolescent where we suspect an eating disorder. It’s important to get their sense of things, how do you feel about your weight. How do you feel about your physical appearance? Are you satisfied with your body image? What are your eating patterns? Do you ever eat in secret or eat in a large amount of food in a short amount of time? That would be a key question for bulimia. Have you ever restricted your food intake? Have you ever tried to lose weight? If so, how? Have you ever tried to control your weight by vomiting, taking laxatives, or diuretics, or excessively exercising? That again is a key for bulimia. It’s important when we’re taking a history that patients are often in denial and very rarely do they just open up and say I suspect they might have an eating disorder.

04:43 They will usually state that their dietary habits are normal. It’s key to ask about inadequate caloric intake.

04:53 It’s important to ask about amenorrhea as that’s a sign of an eating disorder, likewise, so is constipation.

05:01 Ask about fainting or dizzy spells. This is common in patients with eating disorders.

05:08 Ask about cold intolerance, that’s also common or epigastric pain which may be present with excessive vomiting or if they’re having difficulty concentrating. These can all be signs of an eating disorder. Let’s review the physical exam findings in patients with anorexia nervosa.

05:26 These patients will have a very low BMI, usually below 18. They will often have orthostatic hypotension.

05:34 It’s important to check orthostatics in all your patients where you suspect an eating disorder.

05:39 They will have a cachectic appearance as you can see on this slide. They will usually have bradycardia or a slow heart rate. These patients may be hypothermic from being too thin. They often have dry skin.

05:54 They may have cold extremities and they may have an increase in lanugo hair which is that fine soft hair as a result of their cachectic state. Let’s review the physical exam findings in patients with bulimia nervosa.

06:08 This is where they eat frequently and then purge or they may use diuretics or laxatives or excessive exercise.

06:16 These patients will typically have a normal or maybe even an increased weight. They will usually have orthostatic hypotension. They may have salivary gland enlargement. You could check a serum amylase although that is rarely actually positive as a result of this salivary gland enlargement.

06:36 Patients may have dental erosions and this can be a subtle finding but helpful. Here is an example of some dental erosions on a teeth as a result of bulimia nervosa. This happened because of excessive acid expression from repeated emesis. Patients may rarely have knuckle calluses on their fingers from self-induced vomiting, from putting their fingers back into their throat. Lab findings may show something in patients with eating disorders. You may see an anemia as a result of decreased iron or folate or B12 intake but usually, it’s an anemia from low iron. You may see patients with serum electrolyte abnormalities such as hypokalemia. You may see disturbances in albumin.

07:24 A low albumin may indicate a chronically low protein intake. Patients may have abnormal calcium, magnesium, or phosphate. Urinalysis may be important in that it may show abnormalities in patients with eating disorders. Likewise, a sed rate may be elevated. And remember, these patients may have secondary amenorrhea. So, you may see a low LH and and FSH as a result of that. If you obtain an EKG, it would show likely a sinus bradycardia. In bradycardic patients, we do sometimes want to make sure that there’s not for example a prolonged PR interval, or heart block, or something else going on.

08:06 A DEXA scan may be helpful if we’re interested in evaluating just how deficient on calcium these patients are.

08:13 But they usually do have a decreased bone mineral density through both insufficient calcium and phosphate and vitamin D in their diet. Let’s talk about how we treat patients with eating disorders.

08:27 For severe cases, they may require hospitalization. There may be an interdisciplinary team that will be responsible for helping them manage these patients. When they have severe eating disorders especially in patients with severe anorexia, we may have a slow regimented feeding advance to prevent refeeding syndrome which can happen if patients are starved for a prolonged period of time and then suddenly eat a whole large amount of food. The interdisciplinary team should involve both a primary care doctor, a nutritionist, a psychologist, and a psychiatrist. All these people need to work together to help patients with eating disorders. Medical stabilization is sometimes indicated in the inpatient setting. This is necessary in patients who have hypovolemia, who have cardiac dysfunction, or who have electrolyte abnormalities. Nutritional rehabilitation is important.

09:28 These patients need a nutritionist to guide them through how they should be eating.

09:33 We need to replete their nutritional stores of whatever they’re deficient in. Behavioral intervention is key because remember, this is a lot about self-perception. We need psychotherapists and support groups and psychiatrists and psychologists to help with this behavioral intervention. Sometimes medications can be helpful.

09:57 It can be useful if we’re trying to treat comorbid psychiatric conditions such as depression.

10:03 So, it’s really a team approach to helping these kids turn the corner and get better and move on with their lives.

10:10 Thanks so much for your time.