Prevalence and Impact of Diabetes Mellitus Among Patients with Active Pulmonary Tuberculosis in South Korea

South Korea has an increasing prevalence of diabetes and a relatively high burden of tuberculosis. We aimed to determine the prevalence of diabetes in patients with active pulmonary tuberculosis (PTB) and examine the effect of diabetes on tuberculosis treatment outcomes. Data from patients >= 30 years diagnosed with and treated for PTB between January 2010 and December 2012 at Severance Hospital, a 2000-bed tertiary referral hospital in Seoul, South Korea, were analyzed and compared with data from a contemporaneous general population sample extracted from KNHANES V. Diabetes prevalence was 24.2% (252/1044) among patients with PTB and 11.6% (1700/14,655) among controls. Diabetes [odds ratios (OR) 2.56, 95% confidence interval (CI) 1.56-4.21, P < 0.001], male sex (OR 1.93, 95% CI 1.08-3.44, P = 0.027), and cavitary disease (OR 2.08, 95% CI 1.29-3.35, P = 0.003) were significant risk factors for 2-month culture positivity. Diabetes was the only factor associated with unsuccessful treatment outcomes (OR 1.67, 95% CI 1.03-2.70, P = 0.039). The prevalence of diabetes was markedly higher in patients with PTB than in a sample of the general South Korean population. Diabetes may delay sputum conversion and adversely affect treatment outcomes; detection and management of diabetes in patients with PTB is crucial.