Obese, overweight at less TB risk

HONG KONG, June 26 (UPI) -- Chinese people 65 or older who are overweight or obese have a lower risk of tuberculosis than those who are of normal weight, a study found.

The study, published in the Archives of Internal Medicine, found obesity is associated with a lower risk of active pulmonary tuberculosis in the older population of Hong Kong.

Chi C. Leung and colleagues, of Hong Kong's Tuberculosis and Chest Service, studied 42,116 individuals 65 years or older enrolled in 18 health centers for elderly patients in Hong Kong.

The patients were followed up from three months after enrollment in 2000 until Dec. 31, 2005. The body mass index of each patient was measured at the beginning of the study.

Those with a BMI of less than 18.5 were grouped as underweight, 18.5 to less than 23 as normal, 23 to less than 25 as at risk for obesity, 25 to less than 30 as overweight, and 30 or higher as obese. During the follow-up period, 477 cases of active TB were reported.

Baseline BMI obesity at 25 or above was associated with a 30.1 percent decrease in TB risk, whereas BMI lower than 18.5 increased the risk by 6.6 percent, according to the study.