Association between glycemic control and anti-tuberculosis treatment outcomes in patients with diabetes mellitus complicated by pulmonary tuberculosis: a systematic review and meta-analysis of evidence predominantly from China

Tuberculosis remains a major threat to global public health. Diabetes mellitus, one of the most prevalent chronic metabolic diseases worldwide, not only increases the risk of TB but also increases the likelihood of anti-TB treatment failure. Therefore, investigating the role of glycemic control in anti-TB treatment outcomes among patients with TB and comorbid diabetes is of considerable clinical importance. This meta-analysis aimed to provide supplementary evidence on the impact of glycemic control status on objective treatment outcomes in patients with TB and comorbid diabetes. This systematic review and meta-analysis was conducted in accordance with the PRISMA 2020 guidelines. The protocol has been completed and registered with PROSPERO (registration number: CRD420261382487). Eight electronic databases were systematically searched through March 1, 2026, to identify studies evaluating the effect of glycemic control on anti-tuberculosis treatment outcomes in diabetic patients. Study quality was assessed using the Newcastle-Ottawa Scale. Heterogeneity was assessed using the I 2 statistic and Cochran’s Q test. Fixed-effects or random-effects models were used to calculate pooled effect sizes based on the degree of heterogeneity. Certainty of evidence was rated using the GRADE approach. A total of 99 cohort studies were included, comprising 96 from China, 2 from India, and 1 from Pakistan. Compared with good glycemic control, poor glycemic control was associated with significantly lower overall treatment efficacy (original OR = 0.16, 95%CI: 0.13–0.19, p < 0.00001; Egger’s test p＜0.00001, significant publication bias, the adjusted OR = 0.22, 95% CI: 0.16–0.30), sputum conversion rate (original OR = 0.19, 95% CI: 0.17–0.22, p < 0.00001, Egger’s test p = 0.0075, significant bias, the adjusted OR = 0.28, 95% CI: 0.22–0.35),pulmonary lesion resolution rate (original OR = 0.17, 95% CI: 0.15–0.21, p < 0.00001, Egger’s test p ＜0.00001, significant bias, the adjusted OR = 0.28, 95% CI: 0.23–0.34),cavity closure rate (original OR = 0.22, 95% CI: 0.18–0.27, p < 0.00001; Egger’s test p < 0.0001, adjusted OR = 0.23, 95% CI: 0.18–0.30) and a higher recurrence rate (OR = 4.81, 95% CI: 3.17–7.30, p < 0.00001). GRADE ratings indicated low certainty for lesion for overall efficacy, sputum conversion resolution, and recurrence, and very low certainty for cavity closure. Subgroup analysis showed no significant difference between the FBG and HbA1c subgroups for short-term anti-TB treatment outcomes. In exploratory analyses, no clear linear dose–response relationship was observed between glycemic level and sputum conversion, pulmonary cavity closure, or overall treatment efficacy among the included studies. Based on the available data, it could not be demonstrated that longer treatment duration led to significant changes in effect size. Within the limited included literature, poor glycemic control may be associated with smaller post-treatment increases in CD4 + T-cell proportion and CD4 + /CD8 + ratio, whereas no significant difference was observed in CD8 + T-cell changes. Poor glycemic control may also be associated with smaller post-treatment reductions in hs-CRP and ESR. Among Chinese patients with tuberculosis and diabetes mellitus, poorer glycemic control is associated with worse short-term and long-term objective outcomes in patients with tuberculosis. Although causality remains to be established, maintaining adequate glycemic control may be clinically important during anti-tuberculosis treatment. Future randomized controlled trials and mechanistic studies are warranted.