Special to Campus News by Susan Christopher, development manager, Rainbow Babies & Children's Hospital

In a study of more than 900 Cleveland children, researchers at the Case Western Reserve University School of Medicine and Rainbow Babies & Children's Hospital have discovered a surprisingly large number of youth with a serious sleep-related breathing disorder that could make it difficult for them to think or perform well in school and may lead to serious growth or heart problems.

The Cleveland Children's Sleep and Health Study also revealed two groups of children at much greater risk for Sleep Disordered Breathing (SDB)—African-Americans and children who were born prematurely.

African-American children were up to six times as likely as white children to exhibit signs of SDB. This is the first study identifying prematurity as a risk factor for SDB.

Children who were born prematurely, less than 36 weeks gestation, were found to have up to a five times greater risk of SDB than full-term children.

In SDB, there is a prolonged complete or partial airway collapse that disrupts breathing during sleep. It is a common medical problem in adults and is increasingly diagnosed in youth. If unrecognized and untreated, SDB can lead to serious complications for children including behavior and learning problems, growth impairment and even heart ailments. In adults, it can lead to or worsen life-threatening conditions, including an increased risk of hypertension and cardiovascular disease.

Carol Rosen, M.D., associate professor of pediatrics, pulmonology and neurology at CWRU and medical director of Pediatric Sleep Services at Rainbow Babies & Children's Hospital, was primary investigator for the study, which was published in a recent issue of Journal of Pediatrics.

"In previous studies, the prevalence of SDB was based on parental reports of children's snoring, which may be unreliable," Rosen said. "In this study, we actually measured SDB with special equipment in participants' homes, allowing us to get a truer estimate of SDB in children. We found it affected about 2.2 percent of otherwise healthy 8- to 11-year-old children."

Rosen's study of Cleveland children was inspired by an ongoing study of Cleveland families being conducted by her CWRU and Rainbow colleague, Susan Redline, M.D. Redline observed SDB in the children of families where adults suffered from the disorder.

In order to understand how prevalent the disorder was in the general population of children and risk factors for vulnerable populations, Rosen and colleagues supplemented the new Cleveland Children's Sleep and Health Study cohort with more minority children.

The basis for the racial difference isn't clear. Previous research found craniofacial risk factors for SDB differ between racial groups, as does the mode of inheritance.

"More research is needed to understand the risk mechanisms," Rosen said. "Is it related to bone structure or soft tissues? Or is it somehow tied to an increased risk for other conditions, such as diabetes, hypertension or obesity?"

Researchers believe the prematurity risk may be based on negative exposures in the womb or other exposures after birth that influence the development of respiratory control or upper airway size.

"In the womb, face or upper airway shape may not be fully formed or other lung or neurological problems could evolve because of the shortened development period," Rosen continued. "After birth, intensive care procedures, such as exposure to ventilators and extra oxygen, may alter a baby's breathing responses."

The researchers said they believe both African-American and premature babies are more vulnerable to the negative outcomes associated with untreated SDB. African-American children have an increased risk for socioeconomic disadvantage that can exacerbate health problems. Premature children are at higher risk for developmental delays.

Based on their findings, the CWRU and Rainbow researchers say more intensive screening for SDB by primary care providers may be beneficial.

"We've now identified two high risk groups for Sleep Disordered Breathing," Rosen said. "Our research, along with the Academy of Pediatrics' recent recommendation to screen children for snoring and obstructive sleep apnea, should help identify more vulnerable children."

The scientists also said the extent to which unrecognized SDB, especially mild SDB, leads to impaired daytime functioning and health problems needs further study. They are in the process of analyzing their collected data from this study to investigate how SDB affects childhood behavior and learning.

 

Legal Information | © 2003 Case Western Reserve University | Contact the Department