Prevalence and risk factors of pulmonary tuberculosis among people living with diabetes mellitus at the National Referral Hospital, Thimphu, Bhutan

Abstract

Introduction: Diabetes mellitus (DM) is increasing the risk of pulmonary tuberculosis (PTB) with concern over the convergence of these two diseases. Although screening for PTB among people with DM has been recommended by WHO, it has not been implemented in Bhutan yet. Objective: The aim of this study was to determine the prevalence and risk factors of PTB among people living with DM at the National Referral Hospital (NRH), Thimphu, Bhutan.

Methods: This was a cross-sectional study conducted from 1st June – 9th October 2018. All 343 consenting DM patients were screened for PTB using the WHO recommended questionnaire and those with TB positive symptoms were tested for active PTB using sputum smear microscopy and Gene-Xpert. A descriptive statistical analysis was performed using SPSS 21.

Results: The prevalence of PTB among people living with DM was 0.87% (95% CI: 0.20-2.50).The mean age was 54.95 (± 13.2 years) and all were DM type II. The median duration of diabetes was 4 years (range of 0.1-40 years), an average level of HbA1c 7.47 (± 2.6), and median duration on DM medication was 4 years (range of 0.1-40 years) with the majority (88.9%) on oral hypoglycemic drugs. Good glycemic control (HbA1c< 7) was achieved by 39.4% of individuals. PTB risk factors included PTB positive symptoms (7.0%), prior PTB history (5.5%) and recent contact with PTB patient (5.0%). Additional known PTB risk factors were smoking (7.6%), alcohol use (4.1%) and low body mass index (1.5%).

Conclusions: Although the prevalence PTB was low, health education, proper case management and risk based screening for PTB among DM is recommended.