RESULTS: 788 patients treated for TB based on a clinical or microbiologic diagnosis were identified. Pre-existing DM was found in 131 patients (17%) and an incident diagnosis of DM was made in 19 patients (2%). The average hemoglobin A1c was 8.7% and 9.4% in patients with pre-existing and new DM, respectively. HIV co-infection was found in zero patients with DM and 41 patients without DM (7%). Compared to patients without a diagnosis of DM, mortality during TB treatment was higher in patients with pre-existing DM (OR 2.62, 95% CI 1.37-5.02), but not in patients with an incident diagnosis of DM (OR 1.13, 95% CI 0.14-8.72). Patients with pre-existing DM were also more likely to have treatment failure (OR 3.02, 95% CI 1.64- 5.56) compared to those without DM. Both death and relapse contributed to treatment failure in pre-exisitng DM (relapse OR 6.49, 95% CI 1.07-39.19). There were no documented culture positive cases at four months in either group. Patients with DM (incident or prevalent) were more likely to have smear positive disease (44% vs. 34%) and cavitary disease (37% vs. 20%) compared to patients without DM. Drug resistance rates between DM and non DM patients were similar (11% versus 10%, respectively). Ethnicity varied by geographic region, with 326 (91%) of TB cases in Calgary, AB occurring in foreign born patients, versus 229 (53%) of TB cases in Winnipeg, MB occurring in Canadian born Aboriginals. Patterns in clinical presentation, treatment failure, and mortality in patients with DM versus without DM were similar between geographic sites.