Trilateral overlap of tuberculosis, diabetes and HIV-1 in a high-burden African setting: implications for TB control

The diabetes mellitus burden is growing in countries where tuberculosis (TB) and HIV-1 remain major challenges, threatening TB control efforts. This study determined the association between TB and diabetes/impaired glucose regulation in the context of HIV-1. A cross-sectional study was conducted at a TB clinic in Cape Town (South Africa). Participants were screened for diabetes and impaired glucose regulation using fasting plasma glucose, oral glucose tolerance test and glycated haemoglobin (HbA1c). 414 TB and 438 non-TB participants were enrolled. In multivariable analysis, diabetes was associated with TB (OR 2.4, 95% CI 1.3–4.3; p=0.005), with 14% population-attributable risk fraction; however, this association varied by diagnostic test (driven by HbA1c). The association remained significant in HIV-1-infected individuals (OR 2.4, 95% CI 1.1–5.2; p=0.030). A high prevalence of impaired glucose regulation (65.2% among TB cases) and a significant association with TB (OR 2.3, 95% CI 1.6–3.3; p<0.001) was also found. Diabetes and impaired glucose regulation prevalence was high and associated with TB, particularly in HIV-1-infected individuals, highlighting the importance of diabetes screening. The variation in findings by diagnostic test highlights the need for better glycaemia markers to inform screening in the context of TB and HIV-1.