Glitazones are associated with reduced risk of COPD exacerbations and mortality among patients with diabetes
Introduction: Moderators of systemic inflammation may reduce risk of exacerbations among patients with COPD. Glitazones, used in the treatment of diabetes, also have anti-inflammatory properties. We sought to assess whether glitazones were associated with a decreased risk of COPD exacerbations and mortality. Study design: We performed a cohort study between 10/2005-09/2006 of all US veterans who received an oral antihypoglycemic medication (sulfonureas, biguanides, or glitazones) on more than one occasion. Our outcome measures included outpatient COPD exacerbations, hospitalization for COPD, and all cause mortality. Our primary exposure was glitazone use compared to sulfonureas and/or biguanides. We used GEE to estimate the effect of glitazones and to adjust for potential confounding factors. Results: We identified 600,366 patients. Adjustment for age, sociodemographic characteristics, comorbidity, and markers of COPD severity had minimal effects on the point estimates. In comparison to either a sulfonylurea or biguanide, glitazones were associated with a significantly reduced risk of outpatient exacerbation (Adjusted relative likelihood (Adj-RL), 95%CI: 0.79 (0.72-0.86), hospitalization for COPD exacerbation (Adj-RL, 95%CI: 0.82 (0.69-0.97)) and all cause mortality (Adj-RL, 95%CI: 0.89 (0.85-0.93)). These estimates were robust to sensitivity analyses that imposed increasingly strict definitions of COPD. Conclusion: Glitazones were associated with a significant reduction in COPD exacerbations and all cause mortality. We hypothesize that this association may be mediated through the anti-inflammatory properties of glitazones. Funding: Gilead Sciences, Inc., & VA HSRD