Increased Risk of Incident Diabetes Among Individuals With Latent Tuberculosis Infection
RESEARCH DESIGN AND METHODS: We conducted a retrospective cohort study among US Veterans receiving care in the Veterans Health Administration 2000-2015. Eligibility included all patients without pre-existing diabetes who received a tuberculin skin test (TST) or interferon-gamma release-assay (IGRA). We excluded patients with a history of active TB and those diagnosed with diabetes before or within 2 years after LTBI testing. Patients were followed until diabetes diagnosis, death, or 2015. LTBI was defined as TST or IGRA positive. Incident diabetes was defined by use of ICD-9 codes in combination with a diabetes drug prescription.
RESULTS: Among 574,113 eligible patients, 5.3% received both TST/IGRA, 79.1% received TST only, and 15.6% received IGRA only. Overall 6.6% had LTBI, and there were 2,535,149 person-years (PY) of follow-up after LTBI testing (median 3.2 years). The diabetes incidence rate (IR, per 100,000 PY) was greater in patients with LTBI compared to those without (1,012 vs 744; hazard ratio [HR] 1.4, 95%CI 1.3-1.4). Increased diabetes incidence persisted after adjustment for covariates (adjusted HR [aHR] 1.2, 95%CI 1.2-1.3) compared to those without LTBI. Among patients with LTBI, diabetes incidence was similar in those treated for LTBI compared to those who were not treated (aHR 1.0, 95%CI 0.9-1.1).
CONCLUSION: Comprehensive longitudinal data indicate that LTBI is associated with increased diabetes incidence. These results have implications for people with LTBI, ~25% of the global population.