What is the appropriate workup for unintentional weight loss?

From the Guidelines

Unintentional weight loss should be evaluated with a comprehensive history and physical examination, focusing on recent weight loss, with more than 5% involuntary weight loss over 3 months considered significant, as suggested by the ESPEN guidelines for nutrition screening 2002 1. The evaluation should start by documenting the amount and timeframe of weight loss, with significant weight loss defined as >5% of body weight over a short period. Key points to consider in the workup include:

• Documenting the amount and timeframe of weight loss
• Identifying potential causes through a comprehensive history and physical examination
• Laboratory testing, including complete blood count, comprehensive metabolic panel, thyroid function tests, urinalysis, and inflammatory markers like ESR or CRP
• Additional tests based on clinical suspicion, such as HIV testing, tuberculosis screening, stool studies for malabsorption, and age-appropriate cancer screenings
• Imaging studies guided by symptoms, which may include chest X-ray, abdominal imaging, or endoscopy if GI symptoms are present Common causes of unintentional weight loss include malignancy, gastrointestinal disorders, psychological conditions, endocrine disorders, infectious diseases, medication side effects, and age-related factors in elderly patients. For patients with no identified cause after initial evaluation, close monitoring with follow-up in 1-3 months is recommended, with consideration of nutritional support through oral supplements providing additional calories daily, as the condition may reveal undernutrition which was not discovered initially, and may also predict further nutritional deterioration 1. Referral to specialists should be considered if weight loss continues or if specific organ system involvement becomes apparent, to improve outcomes in real-life clinical medicine.

From the Research

Diagnostic Approach

The diagnostic approach for unintentional weight loss involves a thorough history and physical examination to identify potential causes, which can be somatic, functional, or iatrogenic 2, 3.

• A rational approach to patients with unintentional weight loss is based on an understanding of the relevant biologic, psychological, and social factors identified during a thorough history and physical examination 3.
• The goal is to formulate a practical stepwise approach to patient evaluation and management 3.
• Imaging studies, such as computed tomography (CT), are crucial in the diagnosis of unintentional weight loss, particularly with regard to evaluating for the presence of malignancy 4, 5.

Role of Imaging

Imaging modalities, including CT scans, play a significant role in the diagnosis and management of unintentional weight loss.

• CT findings can be organized into four types: definite cause for UWL identified, possible findings for UWL, incidental findings unrelated to UWL, and normal scan 5.
• The use of CT scanning in the evaluation of UWL in the ED yielded a diagnosis in approximately half of all cases, indicating good diagnostic value 5.
• Elevated white blood cell counts and physical exam abnormalities were both significantly associated with CT abnormalities 5.

Common Causes

The common causes of unintentional weight loss include non-malignant gastrointestinal conditions and cancer.

• Non-malignant gastrointestinal conditions accounted for 30% of cases, while cancer accounted for 23% of cases 5.
• A gastrointestinal tract disorder accounts for weight loss in every third patient 6.
• Psychological disorders represented 11% of the non-malignant group 6.

Diagnostic Utility

The diagnostic utility of computed tomography in patients presenting to the emergency department with unintended weight loss is significant.

• CT scans can identify a definite cause for UWL in approximately half of all cases 5.
• The prognosis for unknown causes of weight loss was the same as for non-malignant causes 6.
• If minimal diagnostic procedures cannot establish a diagnosis, then endoscopic investigation of the upper and lower gastrointestinal tract and function tests should be performed to exclude malabsorption 6.