Glycated Hemoglobin Trajectories and Their Association With Treatment Outcomes Among Patients With Pulmonary TB in India: A Prospective Cohort Study

Abstract

Background: Transient hyperglycemia is seen commonly during TB treatment, yet its association with unfavorable treatment outcomes is unclear.

Research question: Does an association exist between glycated hemoglobin (HbA1c) trajectories and TB treatment outcomes?

Study design and methods: Adults with pulmonary TB were evaluated prospectively for 18 months after the second HbA1c measurement. HbA1c trajectories during the initial 3 months of treatment were defined as follows: persistent euglycemia, HbA1c < 6.5% at baseline and 3-month follow-up; persistent hyperglycemia, HbA1c ≥ 6.5% at baseline and 3-month follow-up; transient hyperglycemia, HbA1c ≥ 6.5% at baseline and < 6.5% at 3-month follow-up; incident hyperglycemia, HbA1c < 6.5% at baseline and ≥ 6.5% at 3-month follow-up. Multivariable Poisson regression was used to measure the association between HbA1c trajectories and unfavorable treatment outcomes of failure, recurrence, and all-cause mortality.

Results: Of the 587 participants, 443 participants (76%) had persistent euglycemia, 118 participants (20%) had persistent hyperglycemia, and 26 participants (4%) had transient hyperglycemia. One participant had incident hyperglycemia and was excluded. Compared with participants with persistent euglycemia, those with transient hyperglycemia showed a twofold higher risk of experiencing an unfavorable treatment outcome (adjusted incidence rate ratio [aIRR], 2.07; 95% CI, 1.04-4.15) after adjusting for confounders including diabetes treatment, and BMI; we did not find a significant association with persistent hyperglycemia (aIRR, 1.64; 95% CI, 0.71-3.79). Diabetes treatment was associated with a significantly lower risk of unfavorable treatment outcomes (aIRR, 0.38; 95% CI, 0.15-0.95).

Interpretation: Transient hyperglycemia and lack of diabetes treatment was associated with a higher risk of unfavorable treatment outcomes in adults with pulmonary TB.

Keywords: TB; diabetes mellitus; glycemic status; transient hyperglycemia; treatment outcomes.