Lipid profile and statin use: The paradox of survival after acute exacerbation of chronic obstructive pulmonary disease

Background: A paradoxical association between cholesterol level and clinical outcome has been suggested, yet never previously established, in patients with chronic obstructive pulmonary disease (COPD). Objectives: The authors sought to investigate the interaction between long-term survival, lipid profile and statin use in patients after acute exacerbation of COPD (AECOPD). Methods: A retrospective study evaluating demographic, clinical and laboratory data of 615 consecutive patients admitted for AECOPD over a mean follow-up period of 24.8 months. Kaplan-Meier survival curves and multivariate analysis were used to identify independent prognostic predictors for all-cause mortality. Results: Mean ± standard deviation (SD) age of the study population was 71.8 ± 11.4 years. Unexpectedly, mean serum cholesterol ± SD levels were significantly higher in survivors (N =340) versus nonsurvivors (N= 275): 181.5 ± 43.6 versus 171.6 ± 57.2 mg/dL, respectively, (P= 0.0043). Median survival for patients with cholesterol levels <150 and >200 mg/dL were 16.0 and 64.4 months, respectively (P =0.0173). On multivariate analysis, cholesterol level <150 mg/dL was an independent predictor of mortality, irrespective of cardiovascular risk factors (hazard ratio [HR] 1.8430, 95% confidence interval [CI] =1.2547-2.7072, P= 0.0019). Statin use had an independent protective effect, regardless of cholesterol level (HR= 0.4924, 95% CI= 0.2924-0.8292, P= 0.0080). Conclusions: Low cholesterol levels are significantly associated with increased mortality after AECOPD. Nonetheless, as statin treatment was associated with reduced mortality over the entire range of cholesterol levels, its use should be considered in all COPD patients.