Global, regional, and national prevalence of diabetes mellitus in patients with pulmonary tuberculosis: a systematic review and meta-analysis

Background: Both pulmonary tuberculosis (PTB) and diabetes mellitus (DM) are major global public health problems. We estimated the global, regional, and national prevalence of diabetes mellitus in a population with PTB. Methods: We searched for observational studies of DM in people with PTB using the PubMed and Embase electronic bibliographic databases, focusing on articles published in the English language from database inception until March 31, 2021. We included original research that reported the prevalence of DM in PTB or those that had sufficient data to compute these estimates. Studies were excluded if they did not provide primary data or were case studies or reviews. Two authors independently extracted the articles and collected detailed information using a predefined questionnaire. A country-specific random-effects meta-analysis was used for countries with two or more available studies, and a fractional response regression model was employed to predict the prevalence of DM in PTB for countries with one or no study. The study was registered with the International Prospective Register of Systematic Reviews, using the registration number CRD42018101989. Results: We identified 22,658 studies, and 153, across 51 countries, were retained for data extraction. The global prevalence of DM among patients with PTB was estimated to be 13.73% (95% confidence interval [CI] 12.51–14.95). The prevalence rates were 19.32% (95% CI 13.18–25.46) in the region of the Americas, 17.31% (95% CI 12.48–22.14) in the European region, 14.62% (95% CI 12.05–17.18) in Southeast Asia, 13.59% (95% CI 7.24–19.95) in the western Pacific region, 9.61% (95% CI 4.55–14.68) in the eastern Mediterranean region, and 9.30% (95% CI 2.83–15.76) in the African region. The country with the highest estimated prevalence was the Marshall Islands (50.12%; 95% CI 4.28–95.76). Conclusion: Comorbid PTB and DM remain prevalent worldwide.