Severity of underweight affects the development of nontuberculous mycobacterial pulmonary disease; a nationwide...

Area of Science:

• Pulmonary Medicine
• Infectious Diseases
• Nutritional Science

Background:

• A known association exists between underweight and non-tuberculous mycobacterial pulmonary disease (NTM-PD).
• Previous studies broadly defined underweight using a body mass index (BMI) < 18.5 kg/m².
• The impact of varying underweight severity on NTM-PD risk requires further definition.

Purpose of the Study:

• To investigate the relationship between the severity of underweight and the risk of developing NTM-PD.
• To quantify the increased risk of NTM-PD across different categories of underweight.
• To identify demographic factors that may modify the risk associated with severe underweight.

Main Methods:

• Analysis of health data from 4,332,529 individuals with follow-up until December 2017.
• Categorization of underweight into mild (17.00-18.49 kg/m²), moderate (16.00-16.99 kg/m²), and severe (< 16.00 kg/m²) BMI groups.
• Utilized Cox proportional-hazards analyses to calculate hazard ratios for NTM-PD, referencing a normal BMI range (18.50-22.99 kg/m²).

Main Results:

• Over a median follow-up of 5.6 years, 6,223 participants developed NTM-PD.
• A significant, proportional increase in NTM-PD risk was observed with increasing underweight severity.
• Multivariate adjusted hazard ratios for mild, moderate, and severe underweight were 2.34, 3.50, and 4.35, respectively.

Conclusions:

• NTM-PD risk escalates proportionally with the severity of underweight.
• Severe underweight is a significant risk factor for NTM-PD.
• Younger age (< 65 years) and male sex were found to exacerbate the risk of NTM-PD in individuals with severe underweight.