Tuberculosis and Risk of Emphysema among US Adults in the NHANES I Epidemiologic Follow-Up Study Cohort, 1971-1992.

(1)

Background

History of TB is a known risk factor for long-term respiratory impairment affecting lung functions in both restrictive and obstructive lung disease. (2)

Methods

We analyzed data from the NHANES I Epidemiologic Follow-up Study (NHEFS), a longitudinal study conducted on a noninstitutionalized adult US population aged 25-74 years. Approximately 93 percent of the original NHANES I cohort was successfully traced by the end of the survey period and was available for analysis. The final adjusted model included age groups, gender, family income, lifetime smoking, body mass index (BMI), and frequency of alcohol consumption as potential confounders. (3)

Results

The estimated hazards ratio of developing emphysema during follow-up for individuals with a past diagnosis of TB was 54% lower (95% CI = 0.35, 0.61) that that in individuals with no past TB, after controlling for potential confounders and using proportional hazards regression appropriate to the complex sample design. The association, however, was not statistically significant (HR = 0.86, p-value = 0.38) when only a self-reported history of TB was considered as the exposure in an unadjusted model. (4)

Conclusions

Tuberculosis (self-reported or LTBI) was strongly (but inversely) associated with emphysema incidence. The association was not statistically significant with only a self-reported history of TB as exposure.