Figure 1From: Chronic Obstructive Pulmonary Disease heterogeneity: challenges for health risk assessment, stratification and managementLung injury caused by inhaled irritants like tobacco smoking generates peripheral lung inflammation that may cause "spill over" of different types of cytokines into the systemic circulation. According to this hypothesis, systemic inflammation causes skeletal muscle dysfunction and muscle wasting, but it may also cause and worsen co-morbidities (reproduced from [30]with permission)Back to article page