The metabolic syndrome is a condition frequently found among individuals > 60 years of age. It predisposes affected individuals to systemic inflammation and physical inactivity. Systemic inflammation and physical inactivity are relevant extrapulmonary markers of morbidity and mortality in patients with COPD. Here, we studied the following: (1) the frequency of the coexisting metabolic syndrome in patients with chronic bronchitis (CB) and COPD of different severities; and (2) its association with systemic inflammation and physical inactivity.
In 30 patients with CB (normal spirometry finding) and in 170 patients with COPD (Global Initiative for Chronic Obstructive Lung Disease [GOLD] stages I to IV), we measured the characteristics of the metabolic syndrome, systemic inflammation (high-sensitivity C-reactive protein [hs-CRP], interleukin-6, fibrinogen), and the physical activity level.
The frequencies of the metabolic syndrome in patients with CB, GOLD stages I, II, III, and IV, were 53%, 50%, 53%, 37%, and 44%, respectively (average, 47.5%). The levels of hs-CRP and interleukin-6 were significantly increased in patients with the metabolic syndrome, while the physical activity level was significantly decreased. Multivariate linear regression analyses revealed metabolic syndrome, physical activity level, and CB/GOLD stages to be independent predictors of hs-CRP and interleukin-6 levels, and physical activity level to be a predictor of fibrinogen levels.
In our study, almost one-half of the patients with CB/COPD had coexisting metabolic syndrome, with a slightly lower frequency in patients with severe COPD. The coexisting metabolic syndrome is associated with an increase in the levels of some systemic inflammatory markers and physical inactivity, independent of lung function impairment.