Diabetes mellitus and its associated factors among patients with tuberculosis attending directly observed treatment centres in Oyo State, Nigeria: a cross-sectional evaluation

Objective Diabetes mellitus (DM) and tuberculosis (TB) comorbidity is evolving into an emerging epidemic globally. In Nigeria, a high burden of both diseases, respectively, exists with limited information on tuberculosis-diabetes mellitus (TB-DM) comorbidity. We determined the fasting blood glucose (FBG) level among patients with TB and factors associated with TB-DM comorbidity in Oyo State, South-west Nigeria. Methods A cross-sectional study was conducted among patients with TB aged 15 years and above, who were selected using multistage sampling. Data were collected on patients' biodata, anthropometric measurements and FBG levels using a pretested semistructured questionnaire. The FBG test was conducted on patients with confirmed pulmonary TB (old and newly diagnosed patients with TB) at any stage of anti-TB treatment. Background characteristics and FBG level were summarised using descriptive statistics and factors associated with TB-DM comorbidity were examined at bivariate and multivariable analyses. Results Of the 404 patients with TB, 30 (7.4%) had impaired fasting glucose and 32 (7.9%) were diagnosed with diabetes. The mean age of the male and female respondents was 41 (+/- 14.2) and 36.8 (+/- 15.0), respectively. Females were more likely than males to have diabetes (10.6% vs 6.3%). Median FBG level for the patients was 88 (IQR: Q1: 99, Q3: 79) mg/dL. Age, marital status and educational level were not associated with TB-DM comorbidity. In the multivariable model, only normal body mass index was independently and significantly associated with diabetes. Conclusion TB-DM was prevalent among the studied population in South-west Nigeria. We recommend the integration of DM screening within the continuum of care for TB management.