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Health Capsules
July 2006
Joint, Muscle Problems for Overweight Youth

Children and adolescents who are overweight are more likely than their normal weight counterparts to suffer bone fractures and have joint and muscle pains, according to a new study from NIH’s National Institute of Child Health and Human Development.  Overweight youth in the study were also more likely to develop changes in the knee joint that make movement more difficult.

A total of 355 children and adolescents were classified as overweight (227) or non-overweight (128).  The children had a physical examination and answered questions about whether they had any joint, bone or muscle-related problems.  They were also asked about the impact their weight had on their quality of life, such as whether they have trouble using stairs, feel clumsy or awkward, or have trouble getting up from chairs.  In addition, the researchers used a technique called Dual Energy X-Ray Absorptiometry (DXA) to detect any effects of being overweight on the feet, ankles and knees.

Bone fractures and muscle and joint pain were more common in the overweight youth.  Their most common joint complaint was knee pain.  They were more likely to report mobility problems as well.  DXA scans showed that overweight youth were also more likely to have changes in how the bones of the thigh and leg meet at their knees.

The researchers noted that, while overweight children and adults tend to have stronger bones than their non-overweight counterparts, that didn’t protect those in the study from bone fractures.  This may be because someone who’s overweight can fall with greater force.  Other studies have suggested that overweight boys also have poorer balance, and so are more likely to fall.

“Bone, muscle and joint problems are particularly troubling in this age group,” NIH Director Dr. Elias A. Zerhouni said.  “If overweight youth fail to attain normal weight, they will likely experience an even greater incidence of these problems when they reach later life.”

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We Can! (Ways to Enhance Children’s Activity and Nutrition):, or call toll-free 1-866-35-WECAN

  Smoking Affects Allergy in Infants  

Infants as young as 6 months old can become allergic to things they breathe in, bringing a stuffy nose, sneezing and other symptoms.  In a new study of the environmental factors that might be involved, researchers at the University of Cincinnati found that exposure to more than 20 cigarettes a day was associated with an increased risk of developing such allergies by age one.  Mold, another suspected culprit, didn’t increase the risk for allergy, but it did increase the risk of upper respiratory infections.

Researchers, supported by grants from NIH’s National Institute of Environmental Health Sciences, looked at 633 infants under 1 year old.  They evaluated the impact of tobacco smoke, visible mold, pets, siblings, daycare attendance and breastfeeding practices on both allergy and upper respiratory infections.

They found that infants who are exposed to 20 or more cigarettes per day were almost 3 times more likely to have allergies to airborne compounds at age 1 as those who weren’t exposed.  Infants living in high mold homes were over 5 times more likely to have upper respiratory infections than those who lived in homes where mold wasn’t visible.  Infants with 2 or more older siblings actually had fewer allergy episodes in the first year.  Race, gender, pet ownership and breastfeeding practices didn’t make any difference.

Some of these links have been reported before in older children and adults, but this is the first study to look at all these factors in infants under the age of 1.  These findings highlight the importance of environmental exposures during the first year of life.  Don’t smoke around your infants, and try to get rid of any mold in your house.


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Asthma and Allergy Prevention:

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Tox Town

A Web-based introduction to environmental health risks and toxic chemicals.  Tox Town uses neighborhood scenes—the Farm, City, Town and US-Mexico Border—along with color, graphics, sounds and animation to explain the connections between chemicals, the environment and your health.

From NIH’s National Library of Medicine.

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