Background Uncontrolled diabetes, unlike controlled diabetes, is associated with an impaired immune response. However, little is known about the impact of the status of diabetes control on clinical features and treatment outcomes in patients with pulmonary TB (PTB). We conducted this study to evaluate whether the status of diabetes control influences clinical manifestations and treatment responses in PTB.
Methods A multicentre prospective study was performed between September 2012 and September 2014. The patients were categorised into three groups according to the glycated haemoglobin (HbA1C) level: PTB without diabetes mellitus (non-DM), PTB with controlled diabetes (controlled-DM) and PTB with uncontrolled diabetes (uncontrolled-DM). The primary outcome was the sputum culture conversion rate after 2 months of intensive treatment.
Results Among 661 patients with PTB, 157 (23.8%) had diabetes and 108 (68.8%) had uncontrolled diabetes (HbA1C≥7.0%). The uncontrolled-DM group exhibited more symptoms, positive sputum smears (p<0.001) and presence of cavities (p<0.001) than the non-DM group. Regarding treatment responses, patients with uncontrolled-DM were more likely to have a positive culture after 2 months (p=0.009) and either treatment failure (p=0.015) or death (p=0.027) compared with the non-DM group. In contrast, those with controlled-DM showed similar treatment responses to the non-DM group. In multivariable analysis, uncontrolled diabetes was an independent risk factor for a positive sputum culture after 2 months of treatment (adjusted OR, 2.11; p=0.042) and either treatment failure or death (adjusted OR, 4.11; p=0.022).
Conclusions Uncontrolled diabetes is an independent risk factor for poor treatment response in PTB.
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YSY and JWJ contributed equally.
Contributors JCC, YSY and J-WJ contributed to the conception and design of the study. JCC, YSY, EJJ, J-WJ, HS, YJR, J-JY, YHK, B-HL, YBP and BJL were responsible for acquisition of the data. JCC, HK and YSY performed the data analysis and interpreted the data. JCC, YSY and J-WJ drafted the manuscript. JCC, YSY, EJJ, J-WJ, HS, YJR, J-JY, YHK, B-HL, YBP and BJL contributed intellectually to critical revision of the manuscript and approved the final version.
Funding This research was supported by funds from the Korea Centers for Disease Control and Prevention and Korean Institute of Tuberculosis (2012-KIT-003). The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing interests None declared.
Ethics approval Institutional review boards for all sites including IRB of Chung-Ang University Hospital.
Provenance and peer review Not commissioned; externally peer reviewed.