From the Guidelines
Laboratory tests for a patient with anorexia should include a complete blood count, comprehensive metabolic panel, and electrocardiogram, as recommended by the American Psychiatric Association (1). When evaluating a patient with anorexia, it is essential to consider the potential complications associated with malnutrition and purging behaviors.
- A comprehensive metabolic panel is crucial to assess electrolyte imbalances, liver function, and kidney function, as these can be significantly affected by the disorder (1).
- A complete blood count should be ordered to check for anemia and immune system status, which can be compromised in patients with anorexia (1).
- An electrocardiogram is recommended to evaluate cardiac function and detect arrhythmias caused by electrolyte disturbances, particularly in patients with restrictive eating disorders or severe purging behaviors (1). Additional tests may be necessary to assess nutritional status, reproductive health, and other potential complications associated with anorexia.
- These tests should be guided by the patient's individual needs and medical history, and should be performed regularly throughout treatment to monitor progress and guide medical interventions (1).
From the Research
Laboratory Tests for Anorexia
The following laboratory tests are recommended for patients with anorexia:
- Complete blood count (CBC) to evaluate for anemia, leukopenia, and thrombocytopenia 2
- Electrolyte panel to assess for electrolyte imbalances
- Liver function tests to evaluate for liver damage
- Renal function tests to assess for kidney damage
- Bone mineral density (BMD) test to evaluate for osteoporosis 3, 4, 5
- Hormone level tests, such as thyroid function tests and follicle-stimulating hormone (FSH) levels
- Urinalysis to assess for kidney damage and electrolyte imbalances
Abnormal Laboratory Values
Abnormal laboratory values are common in patients with anorexia, including:
- Anemia, which tends to be normocytic and normochromic 2
- Leukopenia, which manifests as a deficiency of lymphocytes or neutrophils 2
- Thrombocytopenia, which may confer a bleeding risk if severe 2
- Electrolyte imbalances, such as hypokalemia and hypophosphatemia
- Abnormal liver function tests, such as elevated liver enzymes
- Abnormal renal function tests, such as elevated creatinine levels
- Low bone mineral density, which can increase the risk of osteoporosis and fractures 3, 4, 5
Limitations of Laboratory Tests
Laboratory tests may not always be abnormal in patients with anorexia, even in those with severe malnutrition 6. A multi-dimensional evaluation, including a careful history and physical examination, is necessary to diagnose and manage anorexia. The use of laboratory tests without a comprehensive evaluation may be misleading and can delay patient care 6.