Demographic distribution of diabetes–tuberculosis comorbidity in Eastern rural China☆

Objective: China has the second highest burden of tuberculosis (TB) worldwide, and it is also facing a remarkable increase of Diabetes Mellitus (DM) in the population. DM patients are at high risk of contracting TB and patients with DM–TB comorbidity usually present a relatively poor disease progress. To achieve the goal of TB control on incidence and mortality, it is of great importance to understand the epidemiology of DM–TB comorbidity in the Chinese population. This study aims to understand the prevalence of DM–TB comorbidity in newly diagnosed active TB patients and its demographic distribution in eastern rural China. Methods: A population-based cross-sectional study was carried out in four counties in eastern rural China, two in Jiangsu Province (GDP per capita in 2013: 74699.37 yuan, prevalence of DM: 8.50%) and two in Jiangxi Province (GDP per capita in 2013: 31835.53 yuan, prevalence of DM: 7.63%). All newly diagnosed and registered active TB patients from April 2013 to March 2014 were investigated using a structured questionnaire. Fasting blood glucose levels were tested to screen potential DM patients. Confirmation of diagnosis was made by glycosylated hemoglobin A1c (HbA1C). Results: In total, 1406TB patients from four counties were recruited with 447 (33.8%) being smear-positive TB. The average age of patients was 41 years, and the male to female ratio was 1019 (76.2%) to 319 (23.8%). Overall, 71 DM–TB comorbidity patients were detected; of them 52 (73.24%) were from Jiangsu and 19 (26.76%) from Jiangxi. The prevalence of DM–TB comorbidity was 5.05% of the 1406TB patients. The prevalence of DM–TB in Jiangsu (9.29%) was 4.13 times higher than Jiangxi Province (2.25%, p<0.01). It was found that ethnicity, family history of diabetes, diet habit and Province were associated with the prevalence of DM in TB patients. Compared to patients from Jiangxi Province and Han ethnicity patients, TB patients from Jiangsu Province (60.2% vs. 39.8%, OR: 24.17, 95% CI: 4.94–118.32) and minority patients (1.4% vs. 98.6%, OR: 24.29, 95% CI: 1.69–349.11) had a higher prevalence of DM–TB comorbidity. It was found that patients with a family history of DM had an increased possibility of DM–TB comorbidity (2.6% vs. 97.4%, OR: 6.46, 95% CI: 1.05–39.70), as well as those having a diet consisting of salty food (25.2% vs. 74.8%, OR: 3.41, 95% CI: 1.25–9.29). Conclusion: DM–TB comorbidity is more prevalent in areas with better economic status and higher prevalence of DM. Patients with a DM family history might be at high risk of DM–TB comorbidity. A TB control program should be integrated with DM screening and management program in eastern rural China.