Association of accumulated number of underweight with occurrence of tuberculosis

Abstract

Underweight might be a risk factor of tuberculosis (TB), but the association between duration of underweight and occurrence of TB is inconclusive. The objective of this study was to determine whether there is a difference in occurrence of TB according to the cumulative number of underweight in an intermediate TB burden country. The National Health Insurance database was used. Eligible subjects were individuals without history of TB before 2006, and who underwent national health examination between January 2009 and 31 December 2010. Included individuals in the analysis were followed until 31 December 2017. Accumulated number of underweight was defined as the number of times recorded as underweight during the national health examination over four consecutive years. The primary outcome of the study was newly diagnosed TB according to accumulated number of underweight. Among a study population of 2,396,434, TB was identified in 9,322 (3.89%) cases. A high accumulated number of underweight and low body mass index (BMI) level were significantly associated with occurrence of TB. This association remained consistent after adjusting for demographic factors and underlying diseases. In stratified analysis based on age, sex, diabetes (DM), hypertension (HTN), and waist circumference (WC) in metabolic syndrome (MS), the accumulated number of underweight was related consistently to occurrence of TB. A high accumulated number of underweight was associated with increased risk of TB.

Cumulative Burden of Being Underweight Increases the Risk of Hip Fracture: A Nationwide Population-Based Cohort Study

“…This constitutes strong evidence that being underweight must be corrected to prevent hip fractures. Park et al reported that not only being underweight, but also the accumulation of the underweight burden, weakened the immune system and increased the risk for tuberculosis [ 10 ]. Although no report has indicated that underweight accumulation accelerates a decrease in bone density, the literature indicates that being underweight reflects undernutrition; it is likely that bone density will worsen if undernutrition persists, increasing the risk of fracture [ 24 ].…”

“…The cited studies focused on the association between being underweight at one timepoint and the later occurrence of hip fracture. Both a single record of being underweight and accumulated records may increase the risk for disease [ 10 ]. The authors of this study studied the relationship between being underweight and hip fractures using a large-scale cohort, and reported the degree of underweight at one time or the risk of hip fractures according to changes in underweight [ 11 , 12 , 13 ].…”