Vitamin E Status Is Inversely Associated with Risk of Incident Tuberculosis Disease among Household Contacts

Abstract

Few studies have previously assessed how pre-existing vitamin E status is associated with risk of tuberculosis (TB) disease progression. We evaluated the association between baseline plasma concentrations of 3 vitamin E isomers (α-tocopherol, γ-tocopherol, and δ-tocopherol) and TB disease risk. We conducted a case-control study nested within a longitudinal cohort of household contacts (HHCs) of pulmonary TB cases in Lima, Peru. We defined cases as HHCs who developed active TB disease ≥15 d after the diagnosis of the index patient, and we matched each case to 4 control cases who did not develop active TB based on age by year and gender. We used univariate and multivariate conditional logistic regression to calculate ORs for incident TB disease by plasma concentrations of α-tocopherol, γ-tocopherol, and δ-tocopherol. Among 6751 HIV-negative HHCs who provided baseline blood samples, 180 developed secondary TB during follow-up. After controlling for possible confounders, we found that baseline α-tocopherol deficiency conferred increased risk of incident TB disease (adjusted OR: 1.59; 95% CI: 1.02, 2.50; P = 0.04). Household contacts in the lowest tertile of δ-tocopherol were also at increased risk of progression to TB disease compared to those in the highest tertile (tertile 1 compared with tertile 3, adjusted OR: 2.29; 95% CI: 1.29, 4.09; P-trend = 0.005). We found no association between baseline concentration of γ-tocopherol and incident TB disease. Vitamin E deficiency was associated with an increased risk of progression to TB disease among HHCs of index TB cases. Assessment of vitamin E status among individuals at high risk for TB disease may play a role in TB control efforts.