Obese children more susceptible to asthma

A study claims that obese children are more susceptible to asthma that is caused by air pollution.

Obese children exposed to high levels of air pollutants were nearly three times as likely to have asthma, compared with non-obese children and lower levels of pollution exposure, report researchers at Columbia University Medical Center (CUMC), including Columbia's Mailman School of Public Health.

Rates of childhood obesity and asthma have both increased dramatically in the past 30 years. The percentage of American children who are obese has increased from 7% in 1980 to 20% in 2008. Childhood asthma is up from 4% in 1980 to 10% in 2009. Rates are higher among urban minority populations.

The researchers followed 311 children in predominantly Dominican and African-American neighborhoods of New York City. They monitored indoor air in each child’s home for two weeks at age 5 or 6, to measure exposure to a family of air pollutants, polycyclic aromatic hydrocarbons (PAH). The child’s height and weight were measured and respiratory questionnaires were administered. In all, 20% were found to have asthma and 20% were categorized as obese based on body mass index.

The researchers found that high PAH exposure was associated with asthma only among obese children. In particular, the association was with the alkylated forms of PAH, which are emitted by vehicles and by cigarette smoke, cooking, incense, burning candles, and various other indoor sources. A two- to three-fold increase in asthma risk was seen among obese children exposed to high levels of the PAH chemicals 1-methylphenanthrene and 9-methylphenanthrene. Exposure to PAH or obesity alone did not predict asthma.

“Our results suggest that obesity may magnify the effects of these air pollutants, putting children at greater risk for having asthma,” says lead author Kyung Hwa Jung, PhD, associate research scientist in the Department of Medicine at Columbia University College of Physicians and Surgeons (P&S).

The mechanism behind the association is not well understood. One possible explanation is that sedentary lifestyle in obese children could result in more time spent indoors, thereby increasing exposure to indoor PAH. Another may have to do with more rapid breathing in those who are obese.

Better understanding of the risk factors opens the door to more targeted interventions. “These findings suggest that we may be able to bring down childhood asthma rates by curbing indoor, as well as outdoor, air pollution and by implementing age-appropriate diet and exercise programs,” says senior author Rachel Miller, MD, Professor of Medicine (in Pediatrics) and Environmental Health Sciences, chief of Pediatric Allergy and Immunology at CUMC, and co-deputy director of the Columbia Center for Children’s Environmental Health at the Mailman School of Public Health.

The study builds on earlier research findings that linked increased asthma risk with exposure to higher levels of air pollution. Drs. Jung and Miller previously had shown an association between repeated high prenatal and childhood PAH exposure and asthma. A number of studies also have found an association between obesity and asthma.

Support for the study was provided by the National Institute of Health grants R01ES013163, P50ES015905, P01ES09600, R01ES08977, and P30ES09089; Environmental Protection Agency grants R827027, RD832141, and RD834509; the Educational Foundation of America; the John and Wendy Neu Family Foundation; the New York Community Trust; and the Trustees of the Blanchette Hooker Rockefeller Fund.

Matthew Perzanowski, Andrew Rundle, Kathleen Moors, Beizhan Yan, Steven N. Chillrud, Robin Whyatt, David Camann, and Frederica P. Perera also contributed to the study. None of the authors has financial relationships with a commercial entity that has an interest in the subject of this manuscript.

Full results are published in the journal Environmental Research.

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Childhood Obesity Linked To Asthma

Obesity has been linked to a number of diseases associated with inflammation.  This large study provides strong evidence that obese children are more likely to have asthma.  SS 

Kaiser Permanente Study Finds Obesity-Asthma Link in Children Varies by Race/Ethnicity

Electronic Health Records Used to Study 681,000 Youth

By Kaiser Permanente

Published: Monday, Feb. 27, 2012 - 6:08 am

PASADENA, Calif., Feb. 27, 2012 -- PASADENA, Calif., Feb. 27, 2012 /PRNewswire/ -- Children and adolescents who are overweight or obese are more likely to have asthma than their healthy weight counterparts, according to a new Kaiser Permanente Southern California study published in the online edition of Obesity. The study, which included more than 681,000 children between ages 6 and 19, found that the association between asthma and body mass index varied by race and ethnicity.

The study found that the association between BMI and asthma was weaker for African Americans, a group that was previously known to have the highest prevalence of asthma, than for youth from other racial and ethnic groups. Researchers found the strongest association between BMI and asthma in Hispanic youth.

"This research contributes to the growing evidence that there is a relationship between childhood obesity and asthma, and suggests that factors related to race and ethnicity, particularly for Hispanic youth, may modify this relationship," said study lead author Mary Helen Black, PhD, of the Kaiser Permanente Southern California Department of Research & Evaluation. "The study's large and diverse population, which is broadly representative of the Southern California region,allowed us to examine a wide range of BMI categories in relation to asthma among youth from five racial/ethnic groups."

Researchers also found that, among youth with asthma, being overweight or obese was associated with more frequent visits to the doctor or emergency department for asthma. In addition, overweight or obese youth with asthma used more inhaled and oral corticosteroid asthma drugs, when compared to healthy weight youth. The need for these medical treatments could have broader health implications as other studies have suggested a link between these medications and type 2 diabetes. 

The cross-sectional, population-based study included youth from a racially and ethnically diverse population. Asthma was fairly common in this population, affecting about 18 percent of the youth in the study. Researchers used electronic health records to obtain height and weight measurements, asthma diagnoses, and dispensed prescriptions for asthma-specific medications for children and adolescents in the Kaiser Permanente Southern California integrated health planfrom 2007 to 2009. 

This study is part of the Kaiser Permanente Southern California Children's Health Study, and their ongoing work to better understand and prevent childhood obesity.

Last year, the KPSC Children's Health Study found that 7 percent of boys and 6 percent of girls ages 2 to 19 in the population were extremely obese. This study also has used electronic health records to determine that children who were obese or overweight have a significantly higher prevalence of psoriasis, a chronic inflammatory disease of the skin.

Other study authors included Ning Smith,PhD, Steven Jacobsen, MD, PhD, and Corinna Koebnick, PhD, from the Department of Research & Evaluation, Kaiser Permanente Southern California; and Amy H Porter, MD, from the Department of Pediatrics, Kaiser Permanente Los Angeles Medical Center.

Read more here: http://www.sacbee.com/2012/02/27/4294206/kaiser-permanente-study-finds.html#storylink=cpy

http://www.sacbee.com/2012/02/27/4294206/kaiser-permanente-study-finds.html

Snoring and Sleep apnea, is it so inflammatory?

From Dr. Susarla....

Snoring and Sleep apnea, is it so inflammatory?

A recent article in the journal Chest summarizes the association of breathing problems during sleep with multiple other medical conditions in children, raising concerns about how dangerous snoring may be.

Excerpted below: Among the many articles on childhood sleep-disordered breathing (SDB) in the last several years, there is a recurring theme: an array of comorbidities. Whether the disorder is defined as habitual snoring, upper airway resistance syndrome, or obstructive sleep apnea (OSA), studies have consistently linked SDB in children with seemingly unrelated symptoms of neuropsychologic deficits, obesity, cardiovascular abnormalities, parasomnias, and inflammation.

In addition, there appears to be a genetic association for childhood SDB. In the current issue of CHEST (see page 519), Li and colleagues1 have performed a large-scale population survey of symptom clusters and have demonstrated that all of these comorbid symptoms of SDB are increased in a population of children with habitual snoring. Their study in > 6,000 children aged 5 to 14 years with habitual snoring suggests an association of SDB with genetic influences, BMI, neuropsychologic problems, and inflammation, including recent upper-respiratory infection, allergic rhinitis, tonsillitis, and sinusitis. Do these clinical features relate to a single mechanism?

Chest September 2010 138:469-471
http://chestjournal.chestpubs.org/content/138/3/469.full