Chronic obstructive pulmonary disease and the metabolic syndrome: Consequences of a dual threat

Abstract

The metabolic syndrome is found to be more frequent in chronic obstructive pulmonary disease (COPD). The presence of inflammatory markers in circulation, sputum, and broncho-alveolar fluid suggest systemic inflammation is one of the potential mechanisms responsible for both COPD and metabolic syndrome. Physical inactivity, skeletal muscle dysfunction, hypogonadism, and steroid use are also important causes of the metabolic syndrome in COPD. Obesity and insulin resistance is found to be more common in mild to moderate stages (I and II) of COPD. Patients with COPD and the metabolic syndrome have increase risk of morbidity and mortality due to cardiovascular disease. This review describes in details the various components of metabolic syndrome and its impact on long outcomes in COPD patients.

Keywords: Chronic obstructive pulmonary disease; metabolic syndrome; physical inactivity; systemic inflammation.

Figure 1

Pathogenic mechanism linking between the risks factors of COPD and metabolic syndrome. (Adapted from Clini et al. COPD and the metabolic syndrome: An intriguing association. Intern Emerg Med 2013;8:283-9.[50])

Figure 2

Systemic inflammation – spill over hypothesis. (In a patient with COPD there is a spillover of peripheral lung inflammation into systemic circulation which resulted in increased level of various inflammatory markers such as: IL-1β, IL-6, IL-8, and TNF-α. These systemic inflammatory markers are thus responsible for various complication associated with COPD such as; cardiovascular disease, hypertension, skeletal muscle weakness, etc. These systemic inflammatory markers are also responsible for the development of obesity, metabolic syndrome and diabetes in COPD patients. Adapted from Barnes PJ. Chronic obstructive pulmonary disease: Effects beyond the lungs. PLoS Med 2010;7:e1000220.[15])