TNF and chronic obstructive pulmonary disease: Patients with pulmonary hypertension or persistent obstructive pulmonary disease (COPD) and chronic hypoxemia suffer from sarcopenia, which appears to be caused by a change in oxidative metabolism in muscle fibres (OXPHEN phenotype), inflammatory molecules leading to decreased protein synthesis and muscle atrophy (TNF α, IL-6, NF-Kb, m-TOR), imbalance of hormones related to the satiety mechanism (GLP-1/Leptin), or stimulation of oxygenation regulatory molecules (HIF α 1) [87,88].