Targeted medical nutrition for cachexia in chronic obstructive pulmonary disease: a randomized, controlled trial

Aspiration pneumonia induces muscle atrophy in the respiratory, skeletal, and swallowing systems

BACKGROUND

Repetition of the onset of aspiration pneumonia in aged patients is common and causes chronic inflammation. The inflammation induces proinflammatory cytokine production and atrophy in the muscles. The proinflammatory cytokines induce muscle proteolysis by activating calpains and caspase-3, followed by further degradation by the ubiquitin-proteasome system. Autophagy is another pathway of muscle atrophy. However, little is known about the relationship between aspiration pneumonia and muscle. For swallowing muscles, it is not clear whether they produce cytokines. The main objective of this study was to determine whether aspiration pneumonia induces muscle atrophy in the respiratory (the diaphragm), skeletal (the tibialis anterior, TA), and swallowing (the tongue) systems, and their possible mechanisms.

METHODS

We employed a mouse aspiration pneumonia model and computed tomography (CT) scans of aged pneumonia patients. To induce aspiration pneumonia, mice were inoculated with low dose pepsin and lipopolysaccharide solution intra-nasally 5 days a week. The diaphragm, TA, and tongue were isolated, and total RNA, proteins, and frozen sections were stored. Quantitative real-time polymerase chain reaction determined the expression levels of proinflammatory cytokines, muscle E3 ubiquitin ligases, and autophagy related genes. Western blot analysis determined the activation of the muscle proteolysis pathway. Frozen sections determined the presence of muscle atrophy. CT scans were used to evaluate the muscle atrophy in aged aspiration pneumonia patients.

RESULTS

The aspiration challenge enhanced the expression levels of proinflammatory cytokines in the diaphragm, TA, and tongue. Among muscle proteolysis pathways, the aspiration challenge activated caspase-3 in all the three muscles examined, whereas calpains were activated in the diaphragm and the TA but not in the tongue. Activation of the ubiquitin-proteasome system was detected in all the three muscles examined. The aspiration challenge activated autophagy in the TA and the tongue, whereas weak or little activation was detected in the diaphragm. The aspiration challenge resulted in a greater proportion of smaller myofibers than in controls in the diaphragm, TA, and tongue, suggesting muscle atrophy. CT scans clearly showed that aspiration pneumonia was followed by muscle atrophy in aged patients.

CONCLUSIONS

Aspiration pneumonia induced muscle atrophy in the respiratory, skeletal, and swallowing systems in a preclinical animal model and in human patients. Diaphragmatic atrophy may weaken the force of cough to expectorate sputum or mis-swallowed contents. Skeletal muscle atrophy may cause secondary sarcopenia. The atrophy of swallowing muscles may weaken the swallowing function. Thus, muscle atrophy could become a new therapeutic target of aspiration pneumonia.

Targeted medical nutrition for cachexia in chronic obstructive pulmonary disease: a randomized, controlled trial

BACKGROUND

Cachectic patients with chronic obstructive pulmonary disease (COPD) may benefit from nutritional support. This double-blind, randomized, controlled trial evaluated the safety and efficacy of targeted medical nutrition (TMN) vs. an isocaloric comparator in pre-cachectic and cachectic patients with COPD.

METHODS

Patients aged ≥50 years with moderate-to-severe COPD and involuntary weight loss or low body mass index (16-18 kg/m² ) were randomized 1:1 to receive TMN (~230 kcal; 2 g omega-3 fatty acids; 10 μg 25-hydroxy-vitamin D3) or isocaloric comparator twice daily for 12 weeks (ClinicalTrials.gov Identifier: NCT02442908). Primary safety endpoints comprised adverse events and changes in vital signs, laboratory parameters, and concomitant medications. Secondary efficacy endpoints included changes in weight, body composition, exercise tolerance, metabolic biomarkers, and systemic inflammation.

RESULTS

Forty-five patients were randomized to receive TMN (n = 22; mean 69.2 years) or isocaloric comparator (n = 23; mean 69.7 years). TMN was well tolerated. Adverse events were similar in number and type in both groups. Compliance to both products was good (TMN, 79%; comparator, 77%). Both groups gained weight, but the TMN group gained comparatively more fat mass (P = 0.0013). Reductions in systolic blood pressure (P = 0.0418) and secondary endpoints of triglycerides (P = 0.0217) and exercise-induced fatigue (P = 0.0223) and dyspnoea (P = 0.0382), and increases in high-density lipoprotein cholesterol (P = 0.0254), were observed in the TMN vs. the comparator group by week 12.

CONCLUSIONS

Targeted medical nutrition containing high-dose omega-3 fatty acids, vitamin D, and high-quality protein is well tolerated with a good safety profile and has positive effects on blood pressure and blood lipids and on exercise-induced fatigue and dyspnoea. Therefore, this TMN could be clinically beneficial in the nutritional and metabolic support of pre-cachectic and cachectic patients with COPD.

Multidimensional approach for the proper management of a complex chronic patient with chronic obstructive pulmonary disease

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) is frequently associated with comorbidities occurring either independently or as consequences of COPD. Areas covered: This review examines the interactions between the pathophysiology of COPD and the most frequent comorbidities, and highlights the need for multidimensional clinical strategies to manage COPD patients with comorbidities. Expert commentary: Most COPD patients need to be approached in a complex and multifactorial scenario. The diagnosis of COPD is necessarily based on the presence of chronic respiratory symptoms and poorly reversible airflow obstruction, but exacerbations and comorbidities need to be considered in the evaluation of disease severity and prognosis in individual patients. More importantly, defining the precise relationship between COPD and comorbidities for each patient is the basis for a correct therapeutic approach.