Tuberculosis and diabetes mellitus comorbidity in an adult Ugandan population

Abstract

Background: Diabetes mellitus (DM) has a direct impact on the clinical manifestation and prognosis of active tuberculosis disease (TB) and is known to increase the chance of developing the condition. We sought to determine the prevalence of DM in adult Ugandan patients with recently diagnosed TB and the associated sociodemographic, anthropometric, and metabolic characteristics of TB-DM comorbidity.

Methods: In this cross-sectional study conducted at the adult TB treatment centres of three tertiary healthcare facilities in Uganda, we screened adult participants with recently diagnosed TB (diagnosed in < 2 months) for DM. All participants were screened with five tests; initially with a random blood glucose (RBG) test, and then later with fasting blood glucose (FBG), laboratory-based glycated hemoglobin (HbA1c), point-of-care (POC) HbA1c, and oral glucose tolerance test (OGTT) if the RBG was ≥ 6.1 mmol/l. The WHO guidelines for diagnosing and managing DM were used to support the DM diagnosis. To identify the factors associated with DM-TB comorbidity, logistic regression was used.

Results: A total of 232 participants with recently diagnosed TB were screened for DM. Of these, 160 (69%) were female. The median (IQR) age, body mass index, and RBG of all study participants was 35 (27-42) years, 19.2 (17.6-21.3) kg/m2, and 6.1 (5.5-7.2) mmol/l, respectively. About half of the participants (n = 117, 50.4%) had RBG level ≥ 6.1 mmol/l. Of these, 75 (64.1%) participants returned for re-testing. Diabetes mellitus was diagnosed in 32 participants, corresponding to a prevalence of 13.8% (95% CI 9.9-18.9). A new diagnosis of DM was noted in 29 (90.6%) participants. On logistic regression, age ≥ 40 years was associated with increased odds of TB and DM comorbidity (AOR 3.12, 95% CI 1.35-7.23, p = 0.008) while HIV coinfection was protective (AOR 0.27, 95% CI 0.10-0.74, p = 0.01).

Conclusion: TB and DM comorbidity was relatively common in this study population. Routine screening for DM in adult Ugandan patients with recently diagnosed TB especially among those aged ≥ 40 years and HIV-negative patients should be encouraged in clinical practice.

Keywords: Associated factors; Characteristics; Diabetes mellitus; Sub-saharan Africa; Tuberculosis; Uganda.