Less TV and more sleep can help cut weight gain in children
THE PULSE Compiled by Dr Christine White
KIDS who watch too much TV and don’t get enough sleep are increasing their chances of becoming overweight. In the Archives of PediatricsandAdolescentMedicine this week, research has found children who sleep less than 12 hours and watch two or more hours of television a day are twice as likely to become overweight by the age of three than those who sleep more and watch less TV. A total of 915 children were studied. When the children were six months, one year and two years old, their mothers reported their average nightly sleep time and daily TV viewing time. Children who slept less than 12 hours and watched two or more hours of TV a day had a 16 per cent chance of becoming overweight by age three. ArchPediatrAdolescMed 2008;162:305-311 (Taveras EM, et al) DEPRESSION may increase the risk of developing Alzheimer’s disease, concludes a new study in Neurology. Researchers examined 486 people aged 60 to 90 with no symptoms of dementia. Of these, 134 people had experienced at least one episode of depression that required medical attention. In six years, 33 developed Alzheimer’s disease. Those who had suffered from depression were 2.5 times more likely to develop Alzheimer’s disease than people who had never had depression. The risk was even higher for those whose depression occurred before the age of 60 — they were nearly four times more likely to develop Alzheimer’s than those with no depression. Research is needed to discover if there is another factor that causes both depression and Alzheimer’s, say the authors. Neurology 2008;70:1258-1264 (Geerlings MI, et al) PREGNANT women may be spared an unnecessary treatment, with the development of a new blood test published in the British Medical Journal this week. The blood test, given to pregnant women, can determine the blood type of their developing baby. The ‘‘ positive’’ or ‘‘ negative’’ in blood types refers to a protein called the Rhesus (Rh) antigen. If a Rhesus-negative mother has an Rhesuspositive baby, then her immune system may attack the blood cells of her next Rh-positive baby, causing a serious condition called haemolytic disease. To prevent this, all Rhnegative women are given one or two injections during their first pregnancy to ‘‘ train’’ their immune system not to attack an Rh-positive baby. But not all Rh-negative pregnant women will be carrying an Rhpositive baby — in fact, around 38 per cent will have an Rh-negative baby, and will receive the injections unnecessarily. Researchers analysed blood samples from 1997 pregnant women, and compared the results with the baby’s cord blood at birth. In 96 per cent of cases, the test correctly predicted the blood type of the baby from the mother’s blood sample. Using the test would mean only 2 per cent of pregnant women would get the treatment unnecessarily. BMJ 2008;doi:10.1136/ bmj.39518.463206.25 (Finning K, et al) SMALL size at birth and excessive weight gain during adolescence may increase the risk of developing heart disease in later life, according to a new study in the EuropeanHeartJournal. The findings show the importance of staying within the healthy weight range at all stages of life. The study involved 5840 participants who were followed from birth to 31 years of age. Their weight and height were measured at birth, 12 months, 14 years and 31 years of age. At 31 years, they were also given a blood test to assess their levels of inflammation — a known risk factor for heart disease. Those with the lowest birth weights, who then put on the most weight up to the age of 31, had the highest inflammation levels. EurHeartJ 2008;doi:10.1093/eurheartj/ ehn105 (Tzoulaki I, et al) SIMPLE changes to their work schedules could help to improve the health of shift workers, claim the authors of a new study in the AmericanJournalofPreventiveMedicine. Previous studies have found that shift workers are more likely to suffer from sleep disturbances, drug abuse, absenteeism, injuries and accidents compared to other employees. Researchers examined 26 published studies on the health effects of shift work. They found that ‘‘ forward-rotating’’ shifts — for example, a morning shift, followed by an afternoon shift and then a night shift — are less damaging to health than random or backward-rotating shifts. And rotating workers through shift changes every three or four days, rather than every seven days, is better for health and work-life balance. AmJPrevMed 2008;34 (Bambra C, et al) Want to know more? Items are referenced where possible. A reference such as ‘‘ 2007;35:18-25’’ means the source article was published on pages 18-25 in volume number 35 of the publication, in 2007. A doi number or website address is used for research published on a journal’s website.