Prevalence of Diabetes Mellitus and Associated Factors in Patients with Pulmonary Tuberculosis in Maputo and Nampula, Mozambique, 2025: cross-sectional study

Background The comorbidity of Tuberculosis and Diabetes has re-emerged as a significant public health challenge worldwide, affecting 16% of people. In sub-Saharan Africa, the prevalence of comorbidity of Tuberculosis and Diabetes is 9%. Mozambique has high rates of both diseases, but information on their comorbidity is limited. This study aims to estimate the prevalence of Diabetes and determine its associated factors in new cases of pulmonary tuberculosis in Maputo and Nampula provinces, Mozambique. Methods This is an observational, descriptive and cross-sectional study. The study was conducted in six health centres in Maputo and Nampula provinces from February 2021 to February 2025. Pulmonary tuberculosis cases were confirmed by bacilloscopy or GenExpert, and the patients were recruited and tested for Diabetes by measuring their glycosylated haemoglobin (HbA1c). Socio-demographics and clinical variables were obtained through a questionnaire, during medical consultations. Results A total of 866 new cases of Pulmonary Tuberculosis were enrolled, of whom 61.7% (n = 534) were male, with a median age of 36 years. The prevalence of Diabetes mellitus was 17.7% (n = 153, 95% CI 0.15–0.2), and Pre-Diabetes was 12.9% (n = 112, 95% CI 0.11–0.15). In Maputo, the prevalence of Diabetes was 11.2% (n = 84, 95% CI 0.09–0.13), and in Nampula, it was 58.0% (n = 69, 95% CI 0.49–0.67). The variables urban residence (p < 0.001, OR = 2.695, 95% CI [1.5-4.841]) and alcoholic habits (p = 0.002, OR = 2.1, 95% CI [1.323–3.333]) were identified as factors associated with tuberculosis-diabetes comorbidity. Comparing the two provinces, it was observed that Maputo had 32.4% of patients with alcoholic habits compared to 13.3% in Nampula (p = 0.011). In Maputo, 16.4% of patients had a family history of Diabetes mellitus (p = 0.038), a value higher than in Nampula (4.8%), and 35.4% of patients were underweight (p = 0.021) compared to Nampula (42.9%). Conclusion A high prevalence of Diabetes mellitus and Pre-Diabetes was observed in patients with Pulmonary Tuberculosis in Mozambique, mainly in Nampula. Special attention should be paid to patients with Tuberculosis and underweight, as this may be related to Tropical Diabetes.