Weight Loss, Involuntary

Essentials of Diagnosis

• Inquire about

  • Age; caloric intake; secondary confirmation (eg, changes in clothing size)

  • Fever; change in bowel habits

  • Substance abuse

  • Age-appropriate cancer screening history

General Considerations

• Body weight is determined by person's

  • Caloric intake

  • Absorptive capacity

  • Metabolic rate

  • Energy losses

• Involuntary weight loss is clinically significant when it exceeds 5% or more of usual body weight over a 6- to 12-month period

• Often indicates serious physical or psychological illness

• Most common causes

  • Cancer (~30% of cases)

  • Gastrointestinal disorders (~15%)

  • Dementia or depression (~15%)

• In approximately 15–25% of cases, no cause for the weight loss can be found

• In postmenopausal women, unintentional weight loss was associated with increased rates of hip and vertebral fractures

Symptoms and Signs

• History should include medication profile and 24-h diet recall

• Cancer

  • Night sweats

  • Cough

  • Breast mass

  • Constipation

  • Hematochezia

  • Bone pain

• Gastrointestinal disease

  • Nausea

  • Vomiting

  • Diarrhea

  • Abdominal pain

• Depression

  • Anhedonia

  • Sleep disorder

  • Suicidal ideation

  • Recent psychosocial stressors

• Dementia

  • Memory loss

  • Wandering

  • Isolation

• Physical examination for evidence of cancer

Differential Diagnosis

MEDICAL

• Malignancy

• Gastrointestinal disorders, eg, malabsorption, pancreatic insufficiency, peptic ulcer

• Hyperthyroidism

• Chronic heart, lung, or renal disease

• Uncontrolled diabetes mellitus

• Mesenteric ischemia (ischemic bowel)

• Dysphagia

• Anorexia due to azotemia

• Hypercalcemia

• Tuberculosis

• Subacute bacterial endocarditis

• Frailty syndrome

PSYCHOSOCIAL

• Depression

• Dementia

• Alcoholism

• Anorexia nervosa

• Loss of teeth, poor denture fit

• Social isolation

• Poverty

• Inability to shop or prepare food

DRUG-RELATED

• Nonsteroidal anti-inflammatory drugs

• Antiepileptics

• Digoxin

• Selective serotonin reuptake inhibitors

• The history and physical examination should guide the evaluation looking for symptoms and signs that could point to a potential cause (eg, abdominal pain—peptic ulcer disease, tachycardia—hyperthyroidism)

• When the history, physical examination, and basic laboratory studies do not suggest a possible diagnosis, additional evaluation (eg, total body CT scan) is usually low yield

• When no other cause is identified, the frailty syndrome should be considered

Medications

• Appetite stimulants

  • Mild to moderate effectiveness in promoting weight gain

  • But no evidence of any decrease in mortality

  • May cause significant side effects

  • Agents used include

    • Corticosteroids

    • Progestational agents

    • Dronabinol

    • Serotonin antagonists

• Anabolic agents

  • Growth hormone

  • Testosterone derivatives

• Anticatabolic agents

  • Omega-3 fatty acids

  • Pentoxifylline

  • Hydrazine sulfate

  • Thalidomide

Therapeutic Procedures

• Treatment of the underlying disorder

• Consultation with dietician

• Caloric supplementation to achieve intake of 30–40 kcal/kg/day

• Oral feeding is preferred, but temporary nasojejunal tube, or permanent cutaneous gastric or jejunal tube may be necessary

Prognosis

• Rapid unintentional weight loss is predictive of morbidity and mortality

• Mortality rates at 2-year follow-up

  • 8% for unexplained involuntary weight loss

  • 19% for weight loss due to nonmalignant disease

  • 79% for weight loss due to malignant disease

When to Refer

• Weight loss caused by malabsorption

• Persistent nutritional deficiencies despite adequate supplementation

• Weight loss as a result of anorexia or bulimia

When to Admit

• Severe protein-energy malnutrition, including the syndromes of kwashiorkor and marasmus

• Vitamin deficiency syndromes

• Cachexia with anticipated progressive weight loss secondary to unmanageable psychiatric disease

• Careful electrolyte and fluid replacement in protein-energy malnutrition and avoidance of "re-feeding syndrome"