Diabetic Status and Other Risk Factors for Developing Pulmonary Tuberculosis: A Retrospective Cohort Study at King Abdul Aziz University Hospital, Jeddah

Background: Pulmonary and extrapulmonary tuberculosis is an emerging public health challenge among diabetic (DM) patients. Diabetes is a known cause of immunosuppression and is recognized as an independent risk factor for tuberculosis (TB). Diabetes and tuberculosis frequently coexist and influence each other [1]. This study investigates diabetes mellitus as a risk factor for developing pulmonary tuberculosis (PTB) compared to extra-pulmonary tuberculosis (EPTB). 
Materials and Methods: This retrospective cohort study included all culture-confirmed, and PCR-positive TB patients (PTB 522 and EPTB 173) reported to King Abdul Aziz University Hospital, Jeddah, between January 2012 to January 2021. The categorical baseline characteristic of PTB and EPTB patients has been compared with DM status using Pearson chi-square and Fisher's exact test. The univariable and multivariable logistic regression model was used to estimate the association between DM and different sites of TB (PTB and EPTB). 
Results: Of 695 diagnosed TB patients, 215 (30.94%) are diabetic. The percentage of PTB is (75.11%), and EPTB is (24.89%) as a risk factor; DM shows a significant association with PTB in both univariate and multivariate logistic regression analysis. Age, smoking status, dyslipidemia, and other comorbidities are also significantly associated with PTB (P value <0.05). 
Conclusion: In this study, we found a high rate of pulmonary tuberculosis (PTB) among diabetic patients. Proper management of DM and TB infection might increase TB control and prevent PTB and EPTB development in the Saudi population.