Smoking 'ups active TB risk'

Washington, Aug 24 (ANI): Smoking increases the risk of developing active tuberculosis (TB) disease, according to a new study.

The research analysed data from nearly 17,000 individuals in Taiwan as part of Taiwan's 2001 National Health Interview Survey (NHIS).

"In this prospective cohort study we found a two-fold increase in the risk of active TB in current smokers compared with never-smokers," said lead author, Hsien-Ho Lin, postdoctoral research fellow from Brigham and Women's Hospital, in Boston.

The study will be published in the September 1 issue of the American Journal of Respiratory and Critical Care Medicine, published by the American Thoracic Society.

Dr. Lin and collaborators retrieved information from the individual NHIS records on smoking data and exposure to second-hand smoke at home.

They also identified potential confounders, including sex, age, living in a crowded home, household income, marital status, alcohol use and employment. They then identified all incident cases of TB occurring between 2001 and 2004 by using that National Health Insurance database.

When they compared the likelihood of active TB among ever-, never-, and current smokers, they found that ever-smokers had 2.69 times the risk of developing active TB than never-smokers; current smokers had 2.73 times the risk.

After adjusting for potential confounders, the increased risk remained significant for current smokers, who had twice the risk of developing active TB in comparison to never-smokers.

Interestingly, they also found that younger smokers were more likely than smokers older than 65 to develop active TB relative to their non-smoking counterparts.

"The small number of TB cases in this study prevented us from examining the age-gradient of smoking-TB association at a finer age scale, and more studies are needed to confirm these findings," Dr. Lin said.

"Because the baseline risk for active TB is higher in the elderly in many countries, a smaller but still elevated relative risk in this population may yet translate to a greater number of cases of active TB, and our findings should not be interpreted to mean that smoking poses a lower risk in the older population," the expert added. (ANI)