Children who have asthma are less likely to smoke during teen years

A boy who has asthma is less likely to smoke as a teenager, according to a new study from Italy.

Giuseppe Verlato, an epidemiologist at the University of Verona, asked participants to recall whether they smoked between the ages of 11 and 20 and if they had suffered from asthma as young children.

They found that 49 percent of men who smoked as teens did not have asthma in their childhood. This compared to 35.6 percent of men who smoked as teens and had asthma as children.

This "shielding" effect did not apply to girls. For women, 39.4 percent without childhood asthma began smoking before age 20 compared with 41.2 percent of those with asthma.

The study appears online in the Journal of Adolescent Health.

Asthma, a disease that inflames and narrows the breathing airways, occurs in 8 percent to 9 percent of children, said John Carl, head of the pediatric pulmonology department at Cleveland Clinic Children's Hospital.

"Smoking as an asthmatic is kind of like trying to put out a fire with gasoline," he said. "You're adding a lot of inflammation to the type of inflammation that's already there."

The study notes that adolescents with asthma are more prone to psychological problems because of negative social perceptions resulting from their disease. "For girls with asthma, smoking could be a way to increase self-esteem, which has been shown to be lower in girls than boys," the authors wrote.

Carl said other factors affect whether a person starts smoking or not including socio-economic status, race and parents' smoking habits.