In an analysis of nearly 2,500 Latino and African-American children with asthma, the researchers found that children between age 8 and 17 with acute asthma symptoms were far more likely to have had mothers who smoked during pregnancy, even when the team controlled for elements such as education, socioeconomic level and childhood exposure to tobacco smoke.
"If women smoked while pregnant, their children had about a 50 percent increase in uncontrolled asthma, even when we controlled for current tobacco exposure," said Sam S. Oh, PhD, MPH, a postdoctoral scholar in epidemiology at the UCSF Center for Tobacco Research and Education, who is first author on the paper. "Kids who are 17 years old still show the effects of something they were exposed to during the first nine months of life."
The findings are significant in light of the greater proportion of women from ethnic minorities who smoke throughout their pregnancies, the researchers said, as well as the higher rates of asthma within both of those communities than in the overall U.S. population.
The results will appear in an upcoming issue of The Journal of Allergy and Clinical Immunology and can be found in the advance online edition at www.jacionline.com.
Acute asthma significantly affects the quality of life of patients and their families, costing an estimated $56 billion per year in the United States in medical expenses, premature deaths and missed days of work and school, according to the National Institutes of Health.
While extensive research has shown the effect of smoking on asthma risk in young children, the relative contribution of smoking during pregnancy has not been well established, with even less research focused on the populations that are more likely to use tobacco during pregnancy, according to the paper.
The study found that the exact timing of tobacco exposure during pregnancy – whether it was the first trimester or third – was less important than whether they smoked at all, although children with acute symptoms were more likely to have had mothers who smoked for all nine months.
"Most mothers tend to quit smoking as pregnancy progresses, with the majority quitting by the end of the first trimester," Oh said. "But in African-American and Puerto Rican mothers, not only did they smoke more frequently, but they also smoked for a longer time during pregnancy."
An estimated 13.8 percent of American women smoke during pregnancy, according to the U.S. Pregnancy Risk Assessment Monitoring System. Among African-American women, 18.8 percent smoke during pregnancy, as do 6 percent of Puerto Rican mothers and 3.8 percent of Mexican mothers. Findings such as these give a strong incentive to reduce that to zero, the researchers said.
Smoking cessation during pregnancy was uncommon among the Puerto Rican and African-American study participants, with only 35 percent and 29 percent, respectively, quitting smoking before their third trimester. In contrast, 72 percent of the Mexican mothers stopped smoking by the end of the second trimester.
"This could be part of the reason African Americans have higher mortality rates associated with asthma," said Esteban Gonzalez Burchard, MD, MPH, a professor in the UCSF School of Pharmacy whose research focuses on disparities in asthma prevalence, severity and drug responsiveness among diverse racial/ethnic populations. "We know African Americans metabolize nicotine differently than Caucasians. This shows that in utero exposure leads to changes in DNA, but we don't know how that affects asthma later on."
The researchers said the findings highlight one of two possible causes: either the infant's lungs are damaged during development in the womb or in utero exposure to tobacco smoke causes a genetic change that carries over to the next generation.
Asthma is known to be caused by multiple factors, including genetics. The study, which only assessed African-American and Latino children with asthma, found that about 5 percent of those children whose symptoms were controllable through medical treatment had mothers who smoked during pregnancy. By contrast, roughly 12 percent of the children with uncontrolled, or acute, asthma had mothers who smoked.
The study comprised researchers from 17 institutions in the United States, Mexico and Puerto Rico and tapped into two previous, large-scale research projects that Burchard led: the Gene-Environments and Admixture in Latino Asthmatics (GALA II) study, and the Study of African Americans, Asthma, Genes, & Environments (SAGE II).
Funding for the study came from the National Institutes of Health, the American Asthma Foundation, Ernest S. Bazley Trust, the Flight Attendant Medical Research Institute, the Fund for Henry Ford Hospital, RWJF Amos Medical Faculty Award, and the Sandler Foundation. The full list of authors and their affiliations can be found at http://www.jacionline.org/inpress.
UCSF is a leading university dedicated to promoting health worldwide through advanced biomedical research, graduate-level education in the life sciences and health professions, and excellence in patient care. For more information, visit www.ucsf.edu.
Kristen Bole | EurekAlert!
New study points the way to therapy for rare cancer that targets the young
22.11.2017 | Rockefeller University
Penn study identifies new malaria parasites in wild bonobos
21.11.2017 | University of Pennsylvania School of Medicine
The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.
Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
22.11.2017 | Business and Finance
22.11.2017 | Physics and Astronomy
22.11.2017 | Physics and Astronomy