Prevalence of pulmonary tuberculosis in young adult patients with Type 1 diabetes mellitus in India.

Background: There is limited information on prevalence of pulmonary tuberculosis (PTB) in patients with type-1-diabetes. We assessed the prevalence of PTB in patients with type-1-diabetes attending the outpatient-clinic in a tertiary-care hospital.

Methods: 151 patients with type-1-diabetes were screened for PTB by clinical examination and chest-radiography. Sputum Acid-Fast Bacilli Test (AFB) and Mycobacterium tuberculosis (M.tb) culture were performed in patients with clinical and radiological features suggestive of a possibility of PTB and also in those with history of PTB in the past. Their average glycated haemoglobin (HbA1c) during preceding 2 years was assessed. Sputum culture positive patients were managed by a pulmonologist.

Results: 5/151 patients had respiratory symptoms and radiographic findings suggestive of PTB. 20/151 patients were asymptomatic but had history of PTB. Four of the five symptomatic patients and 12 with past PTB were positive for sputum M.tb by culture, giving a prevalence of 10.6 % sputum culture positive in type-1-diabetes. Average HbA1c was comparable in patients with and without positive sputum culture. ESR and Mantoux test were not discriminatory in these groups. Four clinically symptomatic M.tb culture positive and four asymptomatic patients with sputum culture positive for M.tb on two occasions (6 weeks apart) were put on antitubercular treatment (ATT). Patients who were culture positive for M.tb only on one occasion were kept on a close follow up.

Conclusions: Patients with type-1-diabetes mellitus in India have high prevalence of PTB. They need to be actively screened for PTB by sputum M.tb culture in order to initiate early treatment and to prevent transmission in the community.