Serum vitamin D levels and risk of prevalent tuberculosis, incident tuberculosis and tuberculin skin test conversion among prisoners

Elisangela B. Maceda,Crhistinne C. M. Gonçalves,Julio Croda,Jason R. Andrews,Catherine W. Yeckel,Albert I. Ko

doi:10.1038/s41598-018-19589-3

Abstract

Poor vitamin D status has been associated with tuberculosis (TB); whether poor status is cause or consequence of disease is uncertain. We conducted a case-control study and two nested case-control studies to determine whether vitamin D levels were associated with active TB, tuberculin skin test (TST) conversion, and risk of progression to the active TB in prisoners in Brazil. In multivariable conditional logistic regression, subnormal vitamin D levels (OR, 3.77; 95% CI, 1.04–13.64) were more likely in prisoners with active TB. In contrast, vitamin D was not found to be a risk factor for either TST conversion (OR, 2.49; 95% CI, 0.64–9.66) or progression to active disease (OR, 0.59; 95% CI, 0.13–2.62). Black race (OR, 11.52; 95% CI, 2.01–63.36), less than 4 years of schooling (OR, 2.70; 95% CI, 0.90–8.16), cigarette smoking (OR, 0.23; 95% CI, 0.06–0.79) were identified as risk factors for TST conversion. Risk of progression to active TB was found to be associated with cigarette smoking (OR, 7.42; 95% CI, 1.23–44.70). Our findings in the prison population show that poor vitamin D status is more common in individuals with active TB, but is not a risk factor for acquisition of latent TB or progression to active TB.

Highlights

Tuberculosis (TB) is a major global public health problem, causing approximately 1.4 million deaths annually[1]
We aimed to determine whether vitamin D levels were associated with three distinct features of TB disease: active TB, M. tuberculosis infection (tuberculin skin test (TST) conversion), and progression to active disease in this high-risk population
Previous cohort studies conducted among household contacts of TB cases have suggested that low levels of vitamin D may be associated with risk of subsequent M. tuberculosis infection[27] and development of active TB28,29; we did not find these associations in this study when vitamin D levels were examined months prior to diagnosis and found to be largely normal

Summary

Introduction

Tuberculosis (TB) is a major global public health problem, causing approximately 1.4 million deaths annually[1]. Understanding which individuals will progress to TB and which will maintain lifelong immune control or achieve clearance, remains an important scientific question with substantial public health implications This high-risk group provides the opportunity to examine host factors that currently lack complete understanding in the disease pathway for active TB. Of the 526,000 new cases of TB reported between 2009 and 2014 in Brazil, 38,000 (7.3%) were diagnosed among prisoners[9] In this population, the incidence of active TB is at least 30 times higher than that observed in the general population[10]. We aimed to determine whether vitamin D levels were associated with three distinct features of TB disease: active TB, M. tuberculosis infection (tuberculin skin test (TST) conversion), and progression to active disease in this high-risk population

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Discussion

Conclusion