METHODS: We study 5,614 Medicare beneficiaries with COPD and diabetes between 2008 and 2010. Subjects who initiated their antidiabetic medications (metformin, sulfonylurea, insulin and others) between 2008 and 2010 were included. Patients were followed for two years after the initial antidiabetic prescription for all-cause and COPD-related hospitalization. Patients who switched to another antidiabetic or were on multiple antidiabetics during follow-up were excluded. The association between antidiabetic medication use and the outcomes was examined by multivariable logistic regression model after adjusting for patient age, gender, race/ethnicity, dual eligibility, prior hospitalization, oxygen use, gastro-esophageal reflux disease, lung cancer, depression, cardiovascular disease such as ischemic heart disease, cerebrovascular disease, arrhythmia, heart failure, sarcopenia, osteoporosis and COPD medication use. All analyses were performed with SAS version 9.4 (SAS Inc., Cary, NC). ). All reported p-values were two-sided and p<0.05 was considered statistically significant.