Longitudinal trends in glycated hemoglobin during and after tuberculosis treatment

To investigate the impact of pulmonary TB on glycemic status during and after TB treatment, and associations of glycemic trends with antidiabetic therapy and TB outcomes.

Data from two prospective cohort studies of adults in Chennai, India, with pulmonary TB were combined for this analysis. Participants were classified by baseline hemoglobin A1_c (A1C) as having normoglycemia (NG; n = 74), prediabetes (pre-DM; n = 110), or diabetes (DM; n = 244). Repeat A1C measurements were performed at TB treatment months 3 and 6, and then 6 and 12 months after TB treatment completion.

Median A1C at baseline declined after TB treatment initiation in all groups. No baseline NG or pre-DM participants progressed to DM by end of study, while 16.7% of baseline DM participants shifted to pre-DM or NG levels of A1C. In the baseline DM group, rising A1C after the intensive phase of TB treatment was significantly associated with adverse TB outcomes.

Incident TB promotes transient glucose elevation but was not conclusively shown to promote chronic dysglycemia. Rising A1C during and after TB treatment may predict unfavorable treatment response in persons presenting with A1C ≥ 6.5 % at the time of TB diagnosis.