NEW YORK (Reuters Health) – Years of hard trainingmay be to blame for the higher-than-average rates of asthma thatare seen in elite swimmers, the results of a new study suggest.

The study, which compared teenage competitive swimmers withother adolescents, found that the young swimmers were no morelikely than their peers to have airway hypersensitivity andrespiratory symptoms suggestive of asthma.

The implication is that these problems in adult elite swimmersprobably arise after years of training, the researchers report inthe Journal of Allergy and Clinical Immunology.

High-level competitive swimming puts a high oxygen demand on thebody, leading to hyperpnea, or abnormally deep and rapid breathing.This, along with chronic exposure to environmental irritants aroundthe pool, such as chlorine, may lead to airway hyperresponsiveness– a hallmark of asthma in which the airways excessively constrictin response to an environmental trigger.

NEW YORK (Reuters Health) – Women with inadequatelytreated asthma during pregnancy are at increased risk for prematuredelivery, according to a new study.

Medications to treat asthma are often restricted duringpregnancy out of concern for potential harm to the developingchild, even though there is evidence that severe asthma may have aharmful impact on mom and baby.

Dr. Ludmila N. Bakhireva, from the University of New Mexico inAlbuquerque, and her associates studied the potential adverseeffects of poorly controlled asthma in 719 pregnant women enrolledin their “Asthma Medication in Pregnancy Study” between 1998 and2003.

NEW YORK (Reuters Health) – Among infants andchildren with cow’s milk allergy, skin prick test results canpredict which of them are likely to have persistent problems ratherthan spontaneous resolution, according to a report in the Annals ofAllergy, Asthma & Immunology.

Allergic symptoms induced by cow’s milk disappear before thefirst birthday in about half the infants who develop them, theauthors explain, but the natural history of tolerance remainsunclear.

Dr. Alessandro Fiocchi from the University of Milan MedicalSchool, and colleagues determined the prognostic predictors oftolerance in 112 children enrolled in the Milan Cow’s Milk AllergyCohort study.

NEW YORK (Reuters Health) – Patients with anallergy to metal, often first revealed when wearing certainjewelry, are also at risk for reactions to implanted medicaldevices made of metal, such as pacemakers and orthopedicprostheses.

Patch testing, which involves placing some of the suspectedallergen on the skin, can be helpful in detecting medical devicereactions. However, doctors need to wait longer than usual whenlooking to see if a skin reaction has occurred, researchers reportin the Archives of Dermatology.

Normally, researcher Dr. Mark D. P. Davis told Reuters Health,readings at days 3 and 5 “are adequate for detecting contactallergy to most of the common allergens.” In the case of metalallergy, however, the reaction may be delayed and doctors shouldlook again at days 7 to 10.

NEW YORK (Reuters Health) – Active people who areprone to sweating may have some built-in protection fromexercise-induced asthma attacks, a new study suggests.

The unusual connection suggests that the same mechanismsresponsible for generating a person’s sweat “volume” alsodetermines the amount of water secreted by the airways, theresearchers speculate.

Essentially, they say, people who sweat less may also have drierairways, which could make the airways more likely to constrict andcause breathing problems during exercise.

The findings, published in the medical journal Chest, are basedon tests of 56 healthy Marines who had symptoms of exercise-inducedasthma — wheezing, breathless or coughing in response to physicalexertion.

CHICAGO (Reuters) – Women with newly diagnosedbreast cancer who get an MRI scan wait about three weeks longerbefore their surgery and are far more likely to get a mastectomythan women who have only a mammogram, U.S. researchers said onSaturday.

“MRI may not be as good as we think it is,” said Dr. RichardBleicher of the Fox Chase Cancer Center in Philadelphia, whopresented his findings at the American Society of ClinicalOncology’s Breast Cancer Symposium in Washington.

“Those who received an MRI had a three-week delay in the startof their treatment,” Bleicher said in a statement.

“In addition to the treatment delay, we’re concerned that thewell-documented false-positive rate with MRIs may be leading – ormisleading – women into choosing mastectomies.”

NEW YORK (Reuters Health) – Reading patch tests forallergies beyond the customary 5 days may identify certainallergies missed by an earlier reading, according to a newreport.

Patch tests involve keeping a sample of a suspectedallergy-causing substance, or “allergen,” in place next to theskin, and seeing if a reaction develops.

“Late patch test readings were useful when interpretingreactions to metals and topical antibiotics,” Dr. Mark D. P. Davistold Reuters Health.

Davis, from the Mayo Clinic, Rochester, Minnesota, andcolleagues reviewed the records in their database to determinewhich allergens showed positive reactions after day 5.

NEW YORK (Reuters Health) – For people with asthma,those who are obese are nearly five times more likely than theirnon-obese peers to be hospitalized for asthma, new researchindicates.

The findings come from a study of 1113 members of a healthcareorganization who were at least 35 years of age and had activeasthma.

In examining the impact of obesity on asthma outcomes, Dr. DavidM. Mosen from Kaiser Permanente in Portland, Oregon, and colleaguesadjusted for a number of factors known to affect such outcomes,including smoking, oral steroid medication, and gastric refluxdisease.

Compared with normal weight subjects, obese individuals were 2.7times more likely to have poor asthma control, and 4.6 times morelikely to have a history of asthma-related hospitalization, Mosen’steam reports in the Journal of Allergy and Clinical Immunology.

NEW YORK (Reuters Health) – There’s no evidencethat using the allergy/asthma drug Singulair increases the risk ofdepression or suicide, according to a review of data from threeclinical trials.

Recent reports have raised concerns of a link between suicideand Singulair, also known by the generic name montelukast. Thecurrent study, conducted by Dr. Janet Holbrook and Dr. RaidaHarik-Khan from the American Lung Association, indicates that theconcerns are not warranted.

A total of 1352 patients were enrolled in the clinical trials,and 536 were treated with montelukast. All of the trials wereconducted by the American Lung Association’s Asthma ClinicalResearch Centers (ACRC).

NEW YORK (Reuters Health) – The risk of developingasthma is doubled in children who have suffered physical or sexualabuse, new research in Puerto Rico shows.

“Our findings highlight the importance of screening for asthmaamong victims of childhood abuse, and to be aware of thepossibility of physical or sexual abuse among children withasthma,” write Dr. Juan C. Celedon of Harvard Medical School inBoston and his colleagues, noting that their study is the first tofind a link between child abuse and asthma.

Several studies have found higher rates of asthma among PuertoRicans living on the US mainland than among whites, blacks or otherLatinos, the researchers note in the American Journal ofRespiratory and Critical Care Medicine. Research conducted afterSeptember 11, as well as studies in Vietnam vets, has also suggestthat Puerto Rican individuals may suffer greater emotional distresswhen exposed to violence, they add.