Effect of malnutrition on radiographic findings and mycobacterial burden in pulmonary tuberculosis

PLoS One. 2019 Mar 27;14(3):e0214011. doi: 10.1371/journal.pone.0214011. eCollection 2019.

Abstract

Background: The relationship between malnutrition and tuberculosis (TB) severity is understudied. We investigated the effect of malnutrition on radiographic findings and mycobacterial burden.

Methods: Subjects included newly diagnosed, smear-positive, culture-confirmed, pulmonary TB cases enrolled in the Regional Prospective Observational Research for TB (RePORT) cohort. Multivariate regression models were used to evaluate the relationship at start of treatment between body mass index (BMI) and chest radiograph (CXR) findings of cavitation and percentage of lung affected and mycobacterial growth indicator tube (MGIT) time to positive (TTP). Severe malnutrition was defined as BMI<16 kg/m2, moderate malnutrition as 16-18.4kg/m2, and "normal"/overweight as ≥18.5 kg/m2.

Results: Of 173 TB cases with chest x-ray data, 131 (76%) were male. The median age was 45 years (range 16-82); 42 (24%) had severe malnutrition and 58 (34%) moderate malnutrition. Median percentage of lung affected was 32% (range 0-95), and 132 (76%) had cavitation. Individuals with severe malnutrition had, on average, 11.1% [95% CI: 4.0-13.3] more lung affected, compared to those with normal BMI, controlling for diabetes and cavitation. In multivariable analyses, cases with severe malnutrition had a 4.6-fold [95% CI, 1.5-14.1] increased odds of cavitation compared to those with normal BMI, controlling for smoking. Median MGIT TTP was 194.5 hours. Neither severe (aRR 0.99; 95% CI, 0.9-1.2) nor moderate (aRR 0.97; 95% CI, 0.8-1.1) malnutrition was associated with MGIT TTP.

Conclusion: We found that malnutrition was associated with increased extent of disease and cavitation on CXR. These findings may reflect the immunomodulatory effect of malnutrition on pulmonary pathology.

Publication types

  • Observational Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Bacteriological Techniques
  • Body Mass Index
  • Cohort Studies
  • Cross-Sectional Studies
  • Female
  • Humans
  • India
  • Lung / diagnostic imaging
  • Lung / immunology
  • Lung / microbiology
  • Male
  • Malnutrition / complications*
  • Malnutrition / immunology
  • Malnutrition / pathology
  • Middle Aged
  • Mycobacterium tuberculosis / growth & development
  • Mycobacterium tuberculosis / immunology
  • Mycobacterium tuberculosis / isolation & purification
  • Prospective Studies
  • Tuberculosis, Pulmonary / complications*
  • Tuberculosis, Pulmonary / diagnostic imaging
  • Tuberculosis, Pulmonary / microbiology
  • Young Adult

Grants and funding

This work was supported by US Civilian Research & Development Foundation [Award Number USB1-31150-XX-13]; and National Science Foundation [Cooperative Agreement No. OISE-9531011]. This project was funded in whole or in part with Federal funds from the Government of India’s Department of Biotechnology; the Indian Council of Medical Research; the United States National Institutes of Health; National Institute of Allergy and Infectious Diseases; Office of AIDS Research; and distributed in part by US Civilian Research & Development Foundation Global (award to JJE and GR). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.