Screening for pulmonary tuberculosis in type 2 diabetes elderly: a cross-sectional study in a community hospital

Tuberculosis is one of the major infectious diseases in Taiwan. It has an especially high prevalence in diabetes patients, in whom it is usually asymptomatic and are more likely to result in drug-resistant tuberculosis. The aim of the study was to aggressively screen high risk diabetic elderly, identify the prevalence of tuberculosis and its determinants.

Type 2 diabetes patients aged over 65 years were enrolled. They received chest X-rays, blood tests and the questionnaires to assess their medical history and symptoms. Suspicious cases were referred to the pulmonary or infectious disease outpatient clinics. Pulmonary tuberculosis was confirmed by sputum culture. Variables between groups were analyzed by Student t test, Chi-square test or Fisher's exact test. Risk factors were assessed using univariate logistic regression and multiple logistic regression.

A total of 3,087 patients participated this screening program and 7 patients screened positive for pulmonary tuberculosis. Another 5 patients were being under treatment when participating screening program. The prevalence rate was 3.89 per thousand people. The patients with male gender, smoking, liver cirrhosis or subjective body weight loss were associated with an increased risk of tuberculosis significantly. Subjective body weight loss (OR: 6.635 [95% CI: 2.096-21.007]), liver cirrhosis (OR: 10.307 [95% CI: 2.108-50.395]) and history of smoking (OR: 3.981 [95% CI: 1.246-12.718]) are independent risk factors. Among all 73 patients with active tuberculosis or tuberculosis history, they tended to be male, lower body mass index (BMI), more smoking history, more alcohol consumption, more family history of tuberculosis, higher low density lipoprotein (LDL), and less hypertension. However, there was no significant difference in the glycated hemoglobin (HbA1c) levels between the tuberculosis group and non-tuberculosis group.

Active screening program is helpful in detecting pulmonary tuberculosis in elderly diabetes patients. Subjective body weight loss, smoking and liver cirrhosis are independent risk factors.