ASTHMA WATCH

Put Down the Cigarettes

Adolescents who smoke cigarettesregularly may increase the risk of developingasthma during the teen years,compared with nonsmokers the sameage, according to the latest results ofthe Children's Health Study reported inthe American Journal of Respiratory andCritical Care Medicine (November 15,2006).

Over the course of 5 to 8 years (dependingon a participant's age at thestudy's onset), the researchers annuallycollected data on demographic factors,medical histories, household exposures,cigarette smoking, and newly diagnosedasthma through interviews and questionnaireswith 2609 children. The datawere used to estimate a child's relativerisk for new-onset asthma.

The researchers identified 255 casesof new-onset asthma. The participantswho reported smoking ≥300 cigarettesper year had nearly a 4-fold increasedrisk for new-onset asthma, comparedwith nonsmokers. The researchersnoted the increased risk was greater innonallergic children, compared withchildren with a history of allergies.

Lead investigator Frank D. Gilliland,MD, PhD, noted that the adolescentswith the greatest risk for developingasthma were those who were exposedto cigarette smoke while in thewomb and who later picked up thehabit (7 or more cigarettes daily). Theresearchers concluded this combinationled to a >8-fold increased risk ofasthma, compared with unexposednonsmokers.

Is Asthma Misdiagnosed?

A weight problem may increase the odds of being misdiagnosedwith asthma when other health problems are actuallythe reason for shortness of breath and wheezing, concluded astudy reported recently at the American College of ChestPhysicians annual meeting.

Study author Chirag Mehta, MD, explained that individualswho are overweight or obese can produce symptoms similarto asthma, such as shortness of breath from being out ofshape or wheezing from acid reflux disease. To evaluate theaccuracy of asthma diagnoses in the overweight or obese, theresearchers recruited 20 individuals. The participants hadbeen diagnosed with asthma, but their lung-function testssuggested they might not have the disease. The researchersadministered a bronchoprovocation test with a substancecalled methacholine. In this test, the airways of patients withasthma will overact or become hyperresponsive when provokedwith a known irritant.

The findings indicated that only 39% of those overweight orobese individuals tested positive on this test. This means thatnearly 2 of every 3 study participants had been misdiagnosedwith the disease. "A lot of times with increased body mass, youhave deconditioning or you have reflux," said Dr. Mehta.

Flu Spray Works for Asthmatic Kids

Two new studies found that the nasal-spray flu vaccine ismore effective than the inactivated flu-vaccine shot for childrenwith asthma and recurrent respiratory tract infections. The firststudy evaluated the outcomes of 2220 children with asthma,aged 6 to 17 years.

The children were randomly selected to receive the liveattenuated nasal-spray flu vaccine or the inactivated flu shotduring the 2002-2003 influenza season.

The findings showed that the influenza rate in the nasalsprayflu-vaccine group was 4.1%, considerably lower than the6.2% noted in the flu-shot group. The rate of asthma flare-upsand other asthma-related episodes did not differ drasticallybetween the 2 groups.

The second study assessed the efficacy of both vaccines in2187 younger children, aged 6 to 71 months, with a history ofrecurrent respiratory tract infections. The researchers foundthat the nasal-spray flu vaccine was linked with fewer flu casesdue to viral strains similar to the vaccine, compared with the flushot. Furthermore, respiratory tract-related health care visitswere fewer in the nasal-spray group, and the children missedfewer days of school or day care. (The findings were reportedin The Pediatric Infectious Disease Journal, October 2006.)

Work Environment Raises Asthma Risk

Exposure to certain types ofsurface materials in the workplacemay increase adults' oddsof developing asthma, accordingto a study reported in the AmericanJournal of Epidemiology(October 15, 2006).

Studies have linked certainmaterials, pollutants, and evenrenovations to asthma in children.Yet, there has been no evidenceon how such exposuremay impact adults' asthma risk.For the study, the researcherscompared 521 adults newlydiagnosed with asthma over a2¹/²-year period and a controlgroup of 932 adults withoutasthma. The group was questionedabout the materials theywere exposed to at home andat work as well as whether theyhad renovated their homes inthe past year.

The study results indicatedexposure to plastic wall coveringson the job raised the asthmarisk 2.43-fold. Individualswho worked in offices with wall-to-wall carpeting were 1.73times more likely to have developedasthma. The risk morethan quadrupled when moldproblems were present at theworkplace with wall-to-wall carpeting.While home renovationhas no connection with asthma,the researchers noted that individualsliving in homes whereplaster had been used to levelfloors faced an 80% increasedrisk of developing asthma.