Association of Glycemic Status, Lipid Profile, Smoking, and Occupational Exposure with Microbiologically Confirmed Pulmonary Tuberculosis: A Prospective Observational Study

Abstract

Background: Tuberculosis (TB) continues to be a major public health concern, particularly in low- and middle-income countries. Metabolic disorders such as diabetes mellitus and dyslipidemia, along with smoking and occupational exposure, may increase susceptibility to active TB; however, their combined association has not been fully elucidated. Objectives: To evaluate the association of HbA1c, lipid profile, smoking history, and occupational exposure with microbiologically confirmed pulmonary TB in adults attending a tertiary care teaching hospital. Methods: This prospective observational study included 153 adults (20–60 years) with clinically suspected pulmonary TB. Diagnosis was confirmed by Ziehl–Neelsen smear microscopy, GeneXpert MTB/RIF assay, and culture where indicated. Fasting HbA1c and lipid profile were measured using standardized laboratory methods. Associations between clinical variables and confirmed TB were analyzed using univariate and multivariate logistic regression. Results: Pulmonary TB was microbiologically confirmed in 29 (19.0%) participants. Compared with TB-negative individuals, TB patients had significantly higher HbA1c (6.8±1.4 vs. 5.6±0.9%), total cholesterol, triglycerides, and LDL-cholesterol, with lower HDL-cholesterol (all p<0.01). Smoking history (62.1% vs. 33.9%; p=0.006) and high-risk occupation (48.3% vs. 25.0%; p=0.015) were also significantly more common among TB-positive participants. Multivariate analysis identified HbA1c ≥6.5% (adjusted OR 3.2), triglycerides ≥150 mg/dL (adjusted OR 2.4), smoking (adjusted OR 3.8), and high-risk occupation (adjusted OR 2.9) as independent predictors of pulmonary TB. Conclusions: Poor glycemic control, dyslipidemia, smoking, and occupational exposure are independently associated with microbiologically confirmed pulmonary TB. Integrating metabolic assessment and behavioral risk-factor screening into routine TB evaluation may improve early diagnosis and support comprehensive TB control strategies in high-burden settings.