Objective  To explore tuberculosis – diabetes mellitus (DM) comorbidity and its risk factors among retreat-ment pulmonary tuberculosis patients (PTB) and to provide references for prevention and treatment of PTB-DM comorbidity.

  Methods  We recruited 395 retreatment PTB patients at 22 medical institutions designated for PTB treatment across China and divided the patients into a PTB and a PTB-DM group according to the comorbidity of DM; then we carried out a questionnaire survey among all the patients from October 2009 to December 2012. Chi-square test was used to compare differences in demographics and other characteristics between the patients of the two groups; multivariate logistic regression analysis was used to explore risk factors of DM comorbidity.

  Results  Of all the patients, 15.2% (60) were PTB-DM and 84.8% (335) were simple PTB; there were significant differences between the two groups in age (χ² = 10.459, P = 0.005 3), body mass index (BMI) (χ² = 15.070, P = 0.000 5), occupation (χ² = 11.620, P = 0.002 9) and marital status (χ² = 9.999, P = 0.006 7). Aged 40 – 59 years (odds ratio OR = 2.159, 95% confidence interval 95% CI: 1.050 – 4.439), aged 60 years and above (OR = 5.017, 95% CI: 1.485 – 16.951), with a BMI of < 18.5 kg/m² (OR = 4.946, 95% CI: 1.279 – 8.705), with a BMI of ≥ 24 kg/m² (OR = 5.732, 95% CI: 1.918 – 17.133), and being married (OR = 4.476, 95% CI: 1.248 – 10.504) were significant risk factors of PTB-DM comorbidity.

  Conclusion  The complication of diabetes mellitus is associated with age, body mass index, and marital status among retreatment pulmonary tuberculosis patients.