Update on the Etiology, Assessment, and Management of COPD Cachexia: Considerations for the Clinician

Figures & data

Figure 1 Graphical overview of published criteria to diagnose cachexia in patients with COPD. Given the variability in the definition of cachexia, it is important to note that this review covers a wide spectrum of patients and is not limited to a single definition of COPD cachexia. For specific diagnostic criteria and cut off values, the authors refer to the publications from Evans (2008), Muscaritoli (2010), Schols (2014) and McDonald (2019). Pre-cachexia criteria = light; Cachexia criteria = dark. *In cases where weight loss cannot be documented, a body mass index (BMI) <20 kg/m² is sufficient. Based on Evans (2008), fatigue is interpreted as physical and/or mental weariness resulting from exertion and an inability to continue exercise at the same intensity with a resultant deterioration in performance. Based on Evans (2008) and Muscaritoli (2010), anorexia or anorexia-related symptoms are interpreted as limited food intake or poor appetite. Based on Evans (2008) and Muscaritoli (2010), abnormal histochemistry is interpreted as increased inflammatory markers, though anemia or low serum albumin may also be present. Created with BioRender.com.

Abbreviations: CRP, C-reactive protein; FFMI, fat-free mass index; BMI, body mass index; mo, months.

Figure 2 Conceptual framework of etiological factors involved in COPD cachexia. The complex interplay of these factors is depicted via the irregularly shaped black line that links all factors to each other. It illustrates that each factor possibly influences other factors. For every patient with COPD cachexia, the factors involved and their interplay (and consequently the shape of the black line) will be different. Wider space between dashed line = scientific evidence is not consistent or not currently available in patients with COPD. Created with BioRender.com.

Box 1 Ways to Minimize Modifiable Etiological Factors

Encourage smoking cessation Consider oxygen therapy to treat hypoxemia Consider non-invasive ventilation to treat hypercapnia Increase physical activity Improve dietary intake Guide energy conservation Reduce alcohol consumption Treat comorbidities Optimize medical treatment

Box 2 Multimodal Interventions for Cachexia in COPD

Nutritional Supplementation	Exercise Training
A diet with at least 1.2 grams of protein per kg of body weight High-quality proteins (casein, leucine, whey protein) Smaller portions spread over the day Poly unsaturated fatty acids might enhance the effects of exercise training	Resistance training: 12 weeks, at least 2–3 sessions per week, at progressive loads of 30–90% of one-repetition maximum^a Endurance training: 8 weeks, at least 2–3 (1-hour) sessions per week, at >40% of maximal work rate (cycling) or >75% of walking speed achieved during 6MWT or peak speed achieved during incremental shuttle walk test (walking).

Note: ^aThe lower the loads used, the closer to task failure the patient needs to be when performing the exercises in order to obtain positive effects. See Schoenfeld et al for details.

Abbreviation: 6MWT, 6-minute walk test.