nutritional disorders
Protein Energy Undernutrition (PEU)
Diagnosis of Protein Energy Undernutrition
Diagnosis usually based on history To determine severity: Body mass index (BMI), serumalbumin, total lymphocyte count, CD4+ count, and serum transferrin To diagnose complications and consequences: Complete blood count, electrolytes, bloodureanitrogen, glucose, calcium, magnesium, and phosphate Diagnosis of PEU can be based on history when dietary intake is markedly inadequate. The cause of inadequate intake, particularly in children, needs to be identified. In children and adolescents, Overview of Child Maltreatment and Physical examination may include measurement of height and weight, inspection of body fat distribution, and anthropometric measurements of lean body mass. Body mass index (BMI=weight[kg]/height[m]2) is calculated to determine severity. Findings can usually confirm the diagnosis. Laboratory tests are required if dietary history does not clearly indicate inadequate caloric intake. Measurement of serumalbumin, total lymphocyte count, CD4+ T lymphocytes, transferrin, and response to skin antigens may help determine the severity of PEU (see table) or confirm the diagnosis in borderline cases. Many other test results may be abnormal: eg, decreased levels of hormones, vitamins, lipids, cholesterol, prealbumin,insulin-likegrowth factor-1, fibronectin, and retinol-binding protein. Urinary creatinine and methylhistidine levels can be used to gauge the degree of muscle wasting. Because protein catabolism slows, urinaryurealevel also decreases. These findings rarely affect treatment. Laboratory tests are required to identify causes of suspected secondary PEU. C-reactive protein or soluble interleukin-2 receptor should be measured when the cause of undernutrition is unclear; these measurements can help determine whether there is cytokine excess (possibly suggesting otherwise occult inflammatory or wasting disorders such as infection, hyperthyroidism, Human Immunodeficiency Virus (HIV) Infection , or cancer). Thyroid function tests may also be done. Other laboratory tests can detect associated abnormalities that may require treatment. Serum electrolytes, bloodureanitrogen, glucose, and possibly levels of calcium, magnesium, and phosphate should be measured. Levels of blood glucose, electrolytes (especially potassium, occasionally sodium), phosphate, calcium, and magnesium are usually low. Bloodureanitrogen is often low unless renal failure is present. Metabolic acidosis may be present. Complete blood count is usually obtained; normocytic anemia (usually due to protein deficiency) or microcytic anemia (due to simultaneous iron deficiency) is usually present. Stool cultures should be obtained and checked for ova and Diagnosis if diarrhea is severe or does not resolve with treatment. Sometimes urinalysis, urine culture, blood cultures, tuberculin testing, and a chest x-ray are used to diagnose occult infections because people with PEU may have a muted response to infections. 