Introduction: Diabetes mellitus (DM) is a significant comorbidity associated with adverse tuberculosis (TB) treatment outcomes and remains an ongoing clinical challenge. Chronic hyperglycemia impairs host immune responses, particularly macrophage function, leading to delayed bacillary clearance. This contributes to poorer outcomes, including delayed sputum conversion, prolonged treatment duration, relapse, and increased mortality. Poor glycemic control is a key modifiable factor influencing these outcomes. This study aimed to evaluate the impact of glycemic control at diagnosis on TB treatment outcomes in a Malaysian cohort. Methodology: A retrospective cross-sectional audit was conducted using the TB clinic registry at Hospital Sungai Buloh from 2022 to 2025. Adult patients (≥18 years) with confirmed TB (any form) and DM (Type 1 or Type 2) with complete records were included. Of 241 patients screened, 131 were included after exclusions due to incomplete records (29.9%), transfer (29.9%), loss to follow-up (19.9%), and drug-resistant TB (2.9%). Data collected included demographics, hemoglobin A1c (HbA1c) at diagnosis, sputum conversion duration, treatment duration, type of DM therapy, and clinical outcomes. Results: The cohort had a mean age of 53 years, with 97% having Type 2 DM. Mean HbA1c at diagnosis was 10.5%. Poorer glycemic control was associated with delayed sputum conversion. Patients who achieved sputum conversion by 8 weeks had an average HbA1c of 9.6%, compared to 11.8% in those with delayed conversion. Longer treatment duration was associated with higher HbA1c (mean 10.5, 8.6, and 11.8% for 6-, 12-, and 18-month regimens, respectively). Relapse analysis demonstrated a trend towards higher HbA1c with increasing relapse episodes (11.2, 13.75, and 14.5% for one, two, and three relapses, respectively). Overall mortality was 17% (22/131), with markedly higher mean HbA1c in deceased patients compared to survivors (16.0% vs 10.5%). Conclusion Poor glycemic control at TB diagnosis is associated with delayed sputum conversion, prolonged treatment duration, and increased mortality. These findings are consistent with regional evidence, including a South Asian systematic review (Gautam et al., 2021), demonstrating higher mortality and treatment failure in patients with TB and DM. Early and aggressive optimization of glycemic control, alongside standard anti-TB therapy, is essential to improve outcomes.
Humans ; Glycemic Control ; Retrospective Studies ; Diabetes Mellitus ; Treatment Outcome ; Tuberculosis