2.1 Anorexia
Dorota Brilz
I. BACKGROUND. Anorexia is prolonged appetite loss. It is a common symptom of many medical conditions and should be differentiated from the psychiatric disease “anorexia nervosa.”
II. PATHOPHYSIOLOGY
A. General Mechanisms. It is not known exactly how the body regulates appetite stimulation/suppression. It appears that both neural and humoral mechanisms interact. The hypothalamus is believed to regulate both satiety and hunger, leading to homeostasis of body weight in ideal situations. The hypothalamus interprets and integrates a number of neural and humoral inputs to coordinate feeding and energy expenditure in response to conditions of altered energy balance. Long-term signals communicating information about the body’s energy stores, endocrine status, and general health are predominantly humoral. Short-term signals, including gut hormones and neural signals from higher brain centers and the gut, regulate meal initiation and termination. Hormones involved in this process include leptin, insulin, cholecystokinin, ghrelin, polypeptide YY, pancreatic polypeptide, glucagonlike peptide-1, and oxyntomodulin (1). Alterations in any of these humoral or neuronal processes can lead to anorexia.
B. Etiology. Causes of anorexia can be divided into the following four categories:
1. Pathologic. These include malignancy (particularly gastrointestinal, lung, lymphoma, renal, and prostate cancers); gastrointestinal diseases (including peptic ulcer disease, malabsorption, diabetic enteropathy, dysphagia, inflammatory bowel disease, hepatitis, Zenker’s diverticulum, and paraesophageal hernia); infectious diseases (human immunodeficiency virus [HIV], viral hepatitis, tuberculosis, chronic fungal or bacterial disease, chronic parasitic infection, and lung abscess); endocrine disorders (uncontrolled diabetes and adrenal insufficiency); severe heart, lung, and kidney diseases (heart failure; severe obstructive or restrictive lung disease; and renal failure, nephritic syndrome, and chronic glomerulonephritis); neurologic diseases (stroke, dementia, dysphagia, Parkinson disease, and amyotrophic lateral sclerosis); and chronic inflammatory diseases (sarcoidosis, severe rheumatoid arthritis, and giant cell vasculitis).
2. Psychiatric. Affective disorders (depression, bipolar disorder, and generalized anxiety disorder) and food-related delusions from other psychiatric disorders (schizophrenia and related conditions).
3. Pharmacologic. Decreased appetite may be a side effect of one of these medications: topiramate, zonisamide, selective serotonin receptor inhibitors, levodopa, digoxin, metformin, exenatide, liraglutide, nonsteroidal anti-inflammatory drugs, anticancer and antiretroviral drugs, as well as alcohol, opiates, amphetamines, and cocaine. Withdrawal
P.6
from chronic high-dose psychotropic medications and cannabis may cause anorexia. Herbal and nonprescription preparations that cause appetite loss include 5-hydroxytryptophan, aloe, caffeine, cascara, chitosan, chromium, dandelion, ephedra, garcinia, glucomannan, guarana, guar gum, herbal diuretics, nicotine, pyruvate, and St. John’s wort (2).
4. Social factors often cause anorexia. Bereavement, stress, and loneliness may decrease appetite. Moving from one’s home, loss of ability to shop for food or to prepare meals, and financial difficulties may also result in appetite changes.
III. EVALUATION
A. History. Obtaining detailed history is essential in identifying potential causes of patient’s anorexia.
1. History of Present Illness. How long has the problem been going on? Is it constant or episodic? Does the patient associate it with anything? Are there are psychological stressors present? How about difficulty or pain with swallowing?
2. Past Medical History. Any history of chronic medical problems, malignancies, or past psychiatric problems, including eating disorders.
3. Medications and Habits. Use of illicit drugs or any of the above prescription medications that may cause anorexia.
4. Social History. Access to food, to include financial and mobility issues. Patients may experience anorexia if their food is prepared in a manner different from their customary fashion (e.g., patients entering an institution). Patients who may be restricted by their medical professionals to a certain health-related diet may experience lack of appetite due to taste preferences.
5. Review of Systems. Review of systems should focus on weight changes, as well as gastrointestinal, psychiatric, and neurologic systems. A food diary is often helpful to quantify patient’s intake and analyze for the presence of any patterns.
B. Physical Examination.
1. General Appearance. Does the patient appear healthy or ill? Review the vital signs for fever, tachycardia, tachypnea, or blood pressure abnormalities as signs of systemic illness.
2. Head, Eyes, Ears, Nose, and Throat (HEENT). Examine the oral cavity for lesions or poor dentition. Assess for dysphagia/odynophagia and for the presence of lymphadenopathy, thyromegaly, or cervical masses.
3. Cardiovascular System. Assess the patient for arrhythmias and signs of congestive heart failure, such as rales, jugular venous distention, and lower extremity edema.
4. Respiratory System. Auscultate lungs for the presence of wheezes, crackles, or poor air exchange indicating chronic obstructive pulmonary disease or restrictive lung disease.
5. Gastrointestinal System. Listen for abnormal bowel sounds. Examine for tenderness, rigidity, ascites, and hepatomegaly. Rectal examination, including guaiac testing, should be performed (3).
6. Skin. Jaundice, skin tracks, cyanosis, lanugo, hyperpigmentation, and turgor should be noted.
7. Neurologic and Psychological Systems. Examine the functions of cranial nerves, including smell and taste. Look for focal or generalized weakness, gait or balance disturbances, or movement disorders. Assess the patient’s functional capacity and mental status. Assess for anxiety, depression, dementia, delirium, and psychosis.
C. Testing. As in all areas of medicine, diagnostic studies should be guided by the history and physical examination. Tests to consider in anorexia include a complete blood count, electrolyte panel, hepatic panel, and albumin. When assessing nutritional status, measuring prealbumin level may be preferred over albumin level in acute cases of anorexia because prealbumin is the earliest marker of changes in nutritional status (4). Chest x-ray and tuberculosis testing can be helpful in some cases, as might esophagogastroduodenoscopy, colonoscopy, and abdominal computed tomography, or ultrasonography. Other tests to
P.7
include are HIV, thyroid-stimulating hormone and thyroid hormone, viral hepatitis panel, urine protein, and urinalysis (3), and testing for toxicology and drugs of abuse.
IV. DIAGNOSIS. Although the causes of anorexia are numerous and span the biopsychosocial spectrum, a thoughtful evaluation will generally reveal the underlying cause(s) of the loss of appetite, and specific interventions can then be instituted.
REFERENCES
1. Murphy KG, Bloom SR. Gut hormones in the control of appetite. Exp Physiol 2004;89:507-516.Bibliographic LinksExternalResolverBasic
2. Anorexia nervosa in adults: diagnosis, associated clinical features, and assessment. Up To Date 2012. Accessed at http://www.uptodate.com/contents/anorexia-nervosa-in-adults-diagnosis-associated-clinical-features-and-assessment?source-search_result&search =anorexia&selectedTitle=2%7E150 #H549367385 on May 14, 2012.
3. Brooke Huffman G. Evaluating and treating unintentional weight loss in the elderly. Am Fam Physician 2002;65:640-651.Bibliographic LinksExternalResolverBasic
4. Beck FK, Rosenthal TC. Prealbumin: a marker for nutritional evaluation. Am Fam Physician 2002;65:1575-1578.Bibliographic LinksExternalResolverBasic
Dorota Brilz
I. BACKGROUND. Anorexia is prolonged appetite loss. It is a common symptom of many medical conditions and should be differentiated from the psychiatric disease “anorexia nervosa.”
II. PATHOPHYSIOLOGY
A. General Mechanisms. It is not known exactly how the body regulates appetite stimulation/suppression. It appears that both neural and humoral mechanisms interact. The hypothalamus is believed to regulate both satiety and hunger, leading to homeostasis of body weight in ideal situations. The hypothalamus interprets and integrates a number of neural and humoral inputs to coordinate feeding and energy expenditure in response to conditions of altered energy balance. Long-term signals communicating information about the body’s energy stores, endocrine status, and general health are predominantly humoral. Short-term signals, including gut hormones and neural signals from higher brain centers and the gut, regulate meal initiation and termination. Hormones involved in this process include leptin, insulin, cholecystokinin, ghrelin, polypeptide YY, pancreatic polypeptide, glucagonlike peptide-1, and oxyntomodulin (1). Alterations in any of these humoral or neuronal processes can lead to anorexia.
B. Etiology. Causes of anorexia can be divided into the following four categories:
1. Pathologic. These include malignancy (particularly gastrointestinal, lung, lymphoma, renal, and prostate cancers); gastrointestinal diseases (including peptic ulcer disease, malabsorption, diabetic enteropathy, dysphagia, inflammatory bowel disease, hepatitis, Zenker’s diverticulum, and paraesophageal hernia); infectious diseases (human immunodeficiency virus [HIV], viral hepatitis, tuberculosis, chronic fungal or bacterial disease, chronic parasitic infection, and lung abscess); endocrine disorders (uncontrolled diabetes and adrenal insufficiency); severe heart, lung, and kidney diseases (heart failure; severe obstructive or restrictive lung disease; and renal failure, nephritic syndrome, and chronic glomerulonephritis); neurologic diseases (stroke, dementia, dysphagia, Parkinson disease, and amyotrophic lateral sclerosis); and chronic inflammatory diseases (sarcoidosis, severe rheumatoid arthritis, and giant cell vasculitis).
2. Psychiatric. Affective disorders (depression, bipolar disorder, and generalized anxiety disorder) and food-related delusions from other psychiatric disorders (schizophrenia and related conditions).
3. Pharmacologic. Decreased appetite may be a side effect of one of these medications: topiramate, zonisamide, selective serotonin receptor inhibitors, levodopa, digoxin, metformin, exenatide, liraglutide, nonsteroidal anti-inflammatory drugs, anticancer and antiretroviral drugs, as well as alcohol, opiates, amphetamines, and cocaine. Withdrawal
P.6
from chronic high-dose psychotropic medications and cannabis may cause anorexia. Herbal and nonprescription preparations that cause appetite loss include 5-hydroxytryptophan, aloe, caffeine, cascara, chitosan, chromium, dandelion, ephedra, garcinia, glucomannan, guarana, guar gum, herbal diuretics, nicotine, pyruvate, and St. John’s wort (2).
4. Social factors often cause anorexia. Bereavement, stress, and loneliness may decrease appetite. Moving from one’s home, loss of ability to shop for food or to prepare meals, and financial difficulties may also result in appetite changes.
III. EVALUATION
A. History. Obtaining detailed history is essential in identifying potential causes of patient’s anorexia.
1. History of Present Illness. How long has the problem been going on? Is it constant or episodic? Does the patient associate it with anything? Are there are psychological stressors present? How about difficulty or pain with swallowing?
2. Past Medical History. Any history of chronic medical problems, malignancies, or past psychiatric problems, including eating disorders.
3. Medications and Habits. Use of illicit drugs or any of the above prescription medications that may cause anorexia.
4. Social History. Access to food, to include financial and mobility issues. Patients may experience anorexia if their food is prepared in a manner different from their customary fashion (e.g., patients entering an institution). Patients who may be restricted by their medical professionals to a certain health-related diet may experience lack of appetite due to taste preferences.
5. Review of Systems. Review of systems should focus on weight changes, as well as gastrointestinal, psychiatric, and neurologic systems. A food diary is often helpful to quantify patient’s intake and analyze for the presence of any patterns.
B. Physical Examination.
1. General Appearance. Does the patient appear healthy or ill? Review the vital signs for fever, tachycardia, tachypnea, or blood pressure abnormalities as signs of systemic illness.
2. Head, Eyes, Ears, Nose, and Throat (HEENT). Examine the oral cavity for lesions or poor dentition. Assess for dysphagia/odynophagia and for the presence of lymphadenopathy, thyromegaly, or cervical masses.
3. Cardiovascular System. Assess the patient for arrhythmias and signs of congestive heart failure, such as rales, jugular venous distention, and lower extremity edema.
4. Respiratory System. Auscultate lungs for the presence of wheezes, crackles, or poor air exchange indicating chronic obstructive pulmonary disease or restrictive lung disease.
5. Gastrointestinal System. Listen for abnormal bowel sounds. Examine for tenderness, rigidity, ascites, and hepatomegaly. Rectal examination, including guaiac testing, should be performed (3).
6. Skin. Jaundice, skin tracks, cyanosis, lanugo, hyperpigmentation, and turgor should be noted.
7. Neurologic and Psychological Systems. Examine the functions of cranial nerves, including smell and taste. Look for focal or generalized weakness, gait or balance disturbances, or movement disorders. Assess the patient’s functional capacity and mental status. Assess for anxiety, depression, dementia, delirium, and psychosis.
C. Testing. As in all areas of medicine, diagnostic studies should be guided by the history and physical examination. Tests to consider in anorexia include a complete blood count, electrolyte panel, hepatic panel, and albumin. When assessing nutritional status, measuring prealbumin level may be preferred over albumin level in acute cases of anorexia because prealbumin is the earliest marker of changes in nutritional status (4). Chest x-ray and tuberculosis testing can be helpful in some cases, as might esophagogastroduodenoscopy, colonoscopy, and abdominal computed tomography, or ultrasonography. Other tests to
P.7
include are HIV, thyroid-stimulating hormone and thyroid hormone, viral hepatitis panel, urine protein, and urinalysis (3), and testing for toxicology and drugs of abuse.
IV. DIAGNOSIS. Although the causes of anorexia are numerous and span the biopsychosocial spectrum, a thoughtful evaluation will generally reveal the underlying cause(s) of the loss of appetite, and specific interventions can then be instituted.
REFERENCES
1. Murphy KG, Bloom SR. Gut hormones in the control of appetite. Exp Physiol 2004;89:507-516.Bibliographic LinksExternalResolverBasic
2. Anorexia nervosa in adults: diagnosis, associated clinical features, and assessment. Up To Date 2012. Accessed at http://www.uptodate.com/contents/anorexia-nervosa-in-adults-diagnosis-associated-clinical-features-and-assessment?source-search_result&search =anorexia&selectedTitle=2%7E150 #H549367385 on May 14, 2012.
3. Brooke Huffman G. Evaluating and treating unintentional weight loss in the elderly. Am Fam Physician 2002;65:640-651.Bibliographic LinksExternalResolverBasic
4. Beck FK, Rosenthal TC. Prealbumin: a marker for nutritional evaluation. Am Fam Physician 2002;65:1575-1578.Bibliographic LinksExternalResolverBasic
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