Little sleep could make your kid obese

Washington, Feb 8: Children who get too little sleep beginning at age three tend to be overweight five years later, warns a study linking sleep to obesity.

Doctoral student Emily Snell and colleagues at Northwestern University collected sleep data from a national sample of three to 12 year olds. Five years later they took a second look at 1,441 of those children, reported the online edition of health magazine WebMD.

"We found that even an hour of sleep makes a big difference in weight status," Snell said.

"Sleeping an additional hour reduced young children's chance of being overweight from 36 percent to 30 percent while it reduced older children's risk from 34 percent to 30 percent," she says.

The National Sleep Foundation recommends that five to 12 year olds get 10 to 11 hours of sleep each night. Teens should get eight to nine hours of sleep.

Snell and colleagues found that by their seventh birthday children were sleeping less than 10 hours on weekdays. This fell to eight-and-a-half hours by age 14, and to eight hours by 17.

Staying up too late was linked to later weight problems for three to eight years olds, and getting up too early for those in the 8-13 age group.

"Parents should be encouraged to put their younger children to bed early enough so they can sleep at least 10 or 11 hours a night," states the report published in journal Child Development.

"For older children, however, only later wake times were associated with lower rates of overweight. This result supports findings from the growing sleep literature encouraging later school start times, particularly for adolescents."

Passive smokers may face higher heart disease risk

People exposed to passive smoke could face a higher heart disease risk, says a study that directly measured - for the first time - second hand smoke exposure through levels of a nicotine by-product in the blood.

Previous studies have relied on the participants' recall of exposure.

However, in the new study, Andrea Venn, a doctor at the University of Nottingham, and other researchers measured the level of cotinine in the participants' blood, rather than relying on their self-reporting of exposure to second-hand smoke, reported science portal EurekAlert.

Cotinine is an organic compound that indicates levels of nicotine intake. Since nicotine is highly specific to tobacco smoke, blood serum cotinine levels track exposure to tobacco smoke and its toxic components.

The researchers examined data from the third National Health and Nutrition Examination Survey 1988-94 that included 7,599 adults who had never smoked and found that even low-level indirect exposure to cigarette smoke was associated with a significant rise in heart disease risk.

"Even when participants weren't exposed to smoke at the workplace or at home, many had low or high levels of cotinine in their blood," Venn said in the study published in Circulation, a journal of the American Heart Association.

"These people may be exposed in bars or restaurants or perhaps in other people's homes such as those of relatives or friends. This suggests that even people exposed to low levels of second-hand smoke may be at increased risk.

"This study supports existing evidence that exposure to second-hand smoke is an important avoidable cause of cardiovascular disease," the doctor said.

It also highlights the importance of implementing measures to protect the public from second-hand smoke such as banning smoking in enclosed public places and workplaces, Venn added.

Children who sleep less more likely to be overweight

Research indicates that getting inadequate sleep has negative effects on children's social and emotional well-being and school performance. Now a Northwestern University study finds it also increases their risk of being overweight.

The study-conducted in two waves of data collection approximately five years apart-is the first nationally representative, longitudinal investigation of the relationship between sleep, Body Mass Index (BMI) and overweight status in children aged 3 to 18.