Prevalence of pulmonary tuberculosis in diabetic patients attending diabetic clinic at Temeke Regional Referral Hospital in Dar es Salaam

Abstract

Background: There is undeniable evidence that diabetes is a major risk factor for tuberculosis. However, despite this fact there has been a long lapse of time of about 30 years since the last survey of TB among diabetics in Tanzania therefore warranting the need for recent studies. Objective: To determine the prevalence, associated factors and chest radiographic findings for TB among diabetic patients attending the diabetic clinic at Temeke Regional Hospital in Dar es Salaam, Tanzania. Methodology: A descriptive cross-sectional study was conducted at Temeke Regional Referral Hospital diabetes clinic from September to November 2020. A structured questionnaire was used to collect socio-demographic (age, sex, level of education, number of rooms and people in the house, number of people per room, housing floor material, cigarette smoking, alcohol consumption) and clinical characteristics (body mass index, fasting blood glucose, glycated haemoglobin, auscultatory findings on chest examination, previous history of tuberculosis, presence of tuberculosis symptoms, bacilli Calmette-Guerin scar, duration with diabetes, family history of diabetes, Human Immunodeficiency virus status and type of anti-glycaemic agent). Blood samples were taken for fasting blood glucose and glycated haemoglobin analysis. Tuberculosis was confirmed using sputum for GeneXpert and chest radiography was performed for participants with confirmed tuberculosis or symptoms suggestive for tuberculosis. Logistic regression was used to examine for association and control confounders and effect modifier whereby p value of < 0.05 was considered statistically significant. Results: Among 623 patients screened, 11 (1.8%) had tuberculosis disease (95% CI 0.9-3.1). Age groups 45-64 years {aOR 0.39, 95% CI (0.11-0.42)} and > 65 years {aOR 0.34, 95% CI (0.15-0.96)}, cough > 2 weeks {aOR 10, 95% CI (2.42-172.87)}, normal auscultatory findings on chest examination {aOR 0.02, 95% CI (0.01-0.15)} were found to be independently associated with tuberculosis disease. The predominant chest radiographic findings were opacification affecting upper and mid-lung zones on the right lung and bilateral involvement. Conclusion: Our study findings indicate that although there is a decline in the burden of tuberculosis in the diabetic population, the prevalence is still much higher than in the general population, signaling the need for routine screening of tuberculosis in diabetic patients. The association of tuberculosis and diabetes is strongest in the young, with crackles/ bronchial breath sounds and cough >2 weeks. Diagnosing tuberculosis in diabetes mellitus requires a high index of suspicion; therefore, chest radiographic imaging is warranted in all patients who present with suggestive symptoms for tuberculosis regardless of GeneXpert result.