Sleep-disordered breathing, sleep duration could contribute to childhood overweight

By Will Boggs MD

NEW YORK (Reuters Health) - Sleep-disordered breathing (SDB) and shorter sleep duration appear to independently contribute to childhood overweight, according to results from a longitudinal study.

"We need to promote 'sleep health literacy' in our schools, but especially in early childhood education," Dr. Karen Bonuck from Albert Einstein College of Medicine, Bronx, New York, told Reuters Health by email. "The Institute of Medicine, in fact, includes promoting age-appropriate sleep duration as a tool in the fight against obesity, and recommends that health and education professionals be trained in how to counsel parents about their child's sleep."

Both SDB and short sleep duration have been associated with childhood obesity, but until now their independent associations with obesity throughout childhood have remained unexplored.

Dr. Bonuck and colleagues used data from the Avon Longitudinal Study of Parents and Children to examine the independent association between both SDB and sleep duration in early childhood with body mass index (BMI) at ages 7, 10 and 15 years.

The 1,899 participants fell into five SDB categories: asymptomatic throughout (45%); symptoms peaking at six months, then abating (18.5%); symptoms peaking at 18 months, then abating (10.5%); symptoms rising at 18 months, peaking at 30-40 months, then remaining high (the worst case, 7%); and modest symptoms appearing at 42 months and remaining high (19%).

SDB categories were not significantly associated with sleep duration at 18 months, 2.5 years, 5.75 years, or 6.75 years, according to the report, online December 11 in The Journal of Pediatrics.

Children in the worst-case category were 2.15-fold more likely to become obese by 7, 10, and 15 years of age, compared with children in the asymptomatic category.

Children in the late symptom categories had about 80% increased odds of overweight at 7 years and about 60% increased odds of overweight at 15 years, but only a borderline 45% increased odds of obesity at 10 years.

Short sleep duration at 4.75 years old was associated with 2.21-fold increased odds of obesity at 15 years, and short sleep duration at 5.75 years was associated with 55% to 65% increased odds of obesity at 15 years.

In contrast, children with the longest sleep duration at 2.5 years were only half as likely as other children to be obese at 15 years.

"Even though SDB and sleep duration share multiple common pathways to obesity in children, our findings suggest that their effects are of comparable magnitude and independent of one another," the researchers conclude.

"Despite an ever-widening database of interventions aimed at helping children and teens lose weight, their effects range from dismal to moderate," Dr. Bonuck said. "Clearly, preventing obesity in the earliest years -- some believe that a large component of childhood obesity is set by age 5 -- is paramount. In these earliest years, when parents control the sleep schedule, increasing sleep duration is a 'low-hanging fruit' intervention."

"Physicians should consider including discussions about sleep and weight during visits with parents, and supporting them in efforts to entrain healthy sleep habits," she advised. "The time spent will be worth the effort."

"Sleep hygiene practices are surprisingly effective, if implemented consistently," Dr. Bonuck said. "For young children, they include: having a bedtime routine that is interactive (reading, singing, storytelling vs. in front of a screen), having a regular (i.e., consistent) bedtime throughout the week, including on weekends, having a bedtime before 9 pm, and falling asleep alone."

"There is no optimal amount recommended to prevent obesity," Dr. Bonuck said. "There are however age-related amounts of sleep recommended by the National Sleep Foundation (NSF), as well as studies finding increased odds of obesity among short sleeping children. Regarding the NSF, these guidelines include 12-14 hours/24 hour period for children aged 1 to < 3 years, and 11-13 hours/24 hour period for children aged 3 to < 5 years."

"The American Academy of Pediatrics (AAP) recommends that all children be screened for sleep disordered breathing, and then an algorithm to follow for those who screen positive," Dr. Bonuck said. "These guidelines are not new. Yet, when I gave grand rounds to a group of pediatricians -- there were maybe 60 in the room -- I showed the algorithm and asked how many were familiar with it. Just 2 or 3 raised their hands."

"I have had parents tell me that their pediatricians tell them that their child will outgrow the snoring, not to worry about it," she added. "Several years ago, the mother of a school-aged boy called me up to ask what she could do, as her child's pediatrician ignored her concern. I suggested that she see a sleep medicine physician. You know what? She called me several months later to tell me that the sleep doctor said her son had one of the worst cases of sleep apnea he had ever seen. Aside from obesity, the significant and durable effects of sleep disorders on cognition and behavior certainly warrant serious attention."

SOURCE: http://bit.ly/1vRV10C

J Pediatr 2014.

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