What is the workup for cachexia (wasting syndrome)?

From the Guidelines

The workup for cachexia should begin with a comprehensive history and physical examination to identify the underlying cause, as cachexia is typically secondary to conditions like cancer, heart failure, COPD, or chronic infections. Initial laboratory tests should include complete blood count, comprehensive metabolic panel, inflammatory markers (CRP, ESR), thyroid function tests, and albumin levels to assess nutritional status 1. Specific disease-related biomarkers may be needed based on clinical suspicion, such as tumor markers for suspected malignancy. Imaging studies like chest X-ray, CT scans, or MRI may be indicated to identify potential underlying diseases. Functional assessments including grip strength measurement, 6-minute walk test, and body composition analysis (using DEXA scan or bioelectrical impedance) help quantify muscle loss and functional impairment. Nutritional assessment by a dietitian is essential to evaluate caloric intake and needs. Muscle biopsy may occasionally be necessary in unclear cases. This comprehensive approach allows for identification of the underlying cause while simultaneously assessing the severity of cachexia, which is crucial since treatment primarily focuses on addressing the underlying condition while providing nutritional support and potentially using medications like megestrol acetate, corticosteroids, or anamorelin to stimulate appetite and potentially slow muscle wasting 1.

Some key points to consider in the workup and management of cachexia include:

• Identifying and addressing reversible causes of anorexia, such as oropharyngeal candidiasis and depression 1
• Providing nutritional support tailored to the patient's needs and stage of disease 1
• Considering the use of appetite stimulants, such as megestrol acetate or dronabinol, in patients with advanced cancer and cachexia 1
• Focusing on palliative care and symptom management in patients with refractory cachexia or limited life expectancy 1

Overall, a comprehensive and multidisciplinary approach is necessary to effectively manage cachexia and improve patient outcomes. The goal of treatment should be to improve quality of life, reduce symptoms, and slow disease progression, rather than solely focusing on weight gain or muscle mass 1.

From the Research

Diagnostic Criteria for Cachexia

• Cachexia is characterized by the loss of lean body mass with or without the loss of fat, and is associated with increased susceptibility to treatment-related toxicities, decreased quality of life, functional impairment, and increased cancer-related mortality 2.
• The definition of cachexia includes decreased muscle strength and fatigue as diagnostic criteria, with fatigue being frequent and multifactorial in cancer patients, but having limited value to predict cachexia 3.
• Muscle strength should be measured directly to diagnose and monitor cachexia, whereas fatigue is seen as a global outcome 3.

Assessment of Cachexia

• Assessments of BMI and percentage weight loss, symptoms which impact nutritional intake, quality of life, physical function, biological markers, energy expenditure, and body composition are ideally needed to measure cachexia and implement therapeutic interventions 2.
• Routine laboratory parameters such as C-reactive protein (CRP), albumin, and hemoglobin can be used to assess cachexia, but have limitations in terms of sensitivity and negative predictive value 4.
• Physical activity monitoring, applying also body-worn sensors, offers additional monitoring tools for cachexia 3.

Treatment of Cachexia

• Therapeutic approaches for cachexia include appetite stimulants, anti-inflammatory drugs, ghrelin and ghrelin agonists, nutritional support, and anabolics 5.
• Recent clinical trials have investigated different approaches to improve patients' skeletal muscle mass and strength, exercise capacity, and survival in the context of cachexia and body wasting 5.

Prevalence of Cachexia

• The prevalence of protein-energy wasting (PEW) in chronic kidney disease (CKD) patients is 28% to 54% among adults undergoing maintenance dialysis, and increases with declining renal function 6.
• PEW is among the strongest predictors of mortality in CKD patients, with a hazard ratio of 3.03 and a confidence interval of 1.69-5.26 in haemodialysis patients 6.