Archive for November, 2012

Smoking in pregnancy tied to lower reading scores

Yale School of Medicine researchers have found that children born to mothers who smoked more than one pack per day during pregnancy struggled on tests designed to measure how accurately a child reads aloud and comprehends what they read.

The findings are published in the current issue of The Journal of Pediatrics.

Lead author Jeffrey Gruen, M.D., professor of pediatrics and genetics at Yale School of Medicine, and colleagues analyzed data from more than 5,000 children involved in the Avon Longitudinal Study of Parents and Children (ALSPAC), a large-scale study of 15,211 children from 1990-1992 at the University of Bristol in the United Kingdom.

Scored 21% Lower

Gruen and his team from Yale and Brock University in Canada, compared performance on seven specific tasks – reading speed, single-word identification, spelling, accuracy, real and non-word reading, and reading comprehension – with maternal cigarette smoking, after adjusting for socioeconomic status, mother-child interactions, and 14 other potential factors.

They found that on average, children exposed to high levels of nicotine in utero — defined as the minimum amount in one pack of cigarettes per day — scored 21 percent lower in these areas than classmates born to non-smoking mothers. The children were tested at age seven and again at age nine.

Among students who share similar backgrounds and education, a child of a smoking mother will, on average, be ranked seven places lower in a class of 31 in reading accuracy and comprehension ability.

A Significant Difference

“It’s not a little difference — it’s a big difference in accuracy and comprehension at a critical time when children are being assessed, and are getting a sense of what it means to be successful,” said Gruen, who also points out that the effects of smoking in pregnancy are especially pronounced in children with an underlying phonological (i.e., speech) deficit, suggesting an interaction between an environmental exposure (smoking) and a highly heritable trait (phonological ability).

“The interaction between nicotine exposure and phonology suggests a significant gene-by-environment interaction, making children with an underlying phonological deficit particularly vulnerable,” he said.

November 21st, 2012  in Tobacco No Comments »

Even moderate drinking in pregnancy can affect a child’s IQ

Relatively small levels of exposure to alcohol while in the womb can influence a child’s IQ, according to a new study led by researchers from the universities of Bristol and Oxford using data from over 4,000 mothers and their children in the Children of the 90s study (ALSPAC) and published today in PLOS ONE.

Current advice to pregnant women about moderate alcohol consumption during pregnancy is contradictory, with some official guidelines recommending complete abstinence and others suggesting that moderate use is safe. Previous studies have produced conflicting and inconsistent evidence on the effects of moderate alcohol intake on a child’s IQ. This may be because it is difficult to separate the effects of moderate alcohol consumption from other lifestyle and social factors, such as smoking, diet, affluence, mother’s age and education.

Evaluating Moderate Drinking

This study, believed to be the first substantial one of its kind, used genetic variation to investigate the effects of moderate (<1-6 units of alcohol per week) drinking during pregnancy among a large group of women and their children. Since the individual variations that people have in their DNA are not connected to lifestyle and social factors, the approach removes that potential complication.

Four genetic variants in alcohol-metabolising genes among the 4,167 children were strongly related to lower IQ at age eight. The child’s IQ was on average almost two points lower per genetic modification they possessed.

But this effect was only seen among the children of women who were moderate drinkers. There was no effect evident among children whose mothers abstained during pregnancy, strongly suggesting that it was the exposure to alcohol in the womb that was leading to the difference in child IQ. Heavy drinkers were not included in the study.

Different Metabolism Rates

When a person drinks alcohol, ethanol is converted to acetaldehyde by a group of enzymes. Variations in the genes that ‘encode’ these enzymes lead to differences in their ability to metabolise ethanol. In ‘slow metabolisers’, peak alcohol levels may be higher and persist for longer than in ‘fast metabolisers’.

It is believed that the ‘fast’ metabolism of ethanol protects against abnormal brain development in infants because less alcohol is delivered to the fetus, although the exact mechanisms are still unclear.

Previous studies have relied on observational evidence, but this is problematic. Observational studies often find that moderate drinking is beneficial compared to abstention, but this is because mothers who drink in moderation during pregnancy are typically well educated, have a good diet and are unlikely to smoke – all factors which are linked to higher IQ in the child, and which mask any negative effect that exposure to alcohol may have.

More Than 4,000 Women Studied

This study, on the other hand, looked at moderate (rather than high) alcohol intake in over 4,000 women and used a novel technique known as Mendelian randomization, which is a scientifically robust way of investigating the links between exposures and later diseases, using genetic variants which modify exposure levels and which are not influenced by lifestyle or other factors.

The mothers’ alcohol intake was based on a questionnaire completed when they were 18 weeks’ pregnant. It included questions on the average amount and frequency of alcohol consumption before the current pregnancy, during the first trimester, and in the previous two weeks or at the time when they first felt the baby move. One drink was specified as one unit of alcohol.

Around 32 weeks of gestation the mother completed another questionnaire in which she was asked about her average weekday and weekend alcohol consumption, from which weekly intake was derived. Any woman who reported drinking, even if it was less than one unit per week either in the first trimester or when she felt the baby first move was classified as drinking during pregnancy.

Children’s IQ Tested at Age 8

At approximately 18 and 32 weeks of pregnancy, the women were also asked on how many days during the past month they had drunk two pints of beer (or the equivalent amount of alcohol). Any women who reported doing this on at least one occasion was classified as a binge drinker for the purposes of this analysis and were excluded.

The children’s IQ was tested when they were aged eight using a shortened version of the Wechsler Intelligence Scale for Children from which an overall age adjusted total score was derived.

Speaking about the findings, the report’s main author, Dr Sarah Lewis, said:

Moderate Drinking Not Harmless

‘Our results suggest that even at levels of alcohol consumption which are normally considered to be harmless, we can detect differences in childhood IQ, which are dependent on the ability of the foetus to clear this alcohol. This is evidence that even at these moderate levels, alcohol is influencing foetal brain development.’

Dr Ron Gray from the University of Oxford who led the research added:

‘This is a complex study but the message is simple: even moderate amounts of alcohol during pregnancy can have an effect on future child intelligence. So women have good reason to choose to avoid alcohol when pregnant.’

November 20th, 2012  in Alcohol No Comments »

Boys more likely to abuse over-the-counter meds

As crackdowns get tougher on alcohol, tobacco sales, and illicit drugs, there’s a growing trend among youth to turn to another source to get high: their parent’s medicine cabinet. A new University of Cincinnati study suggests adolescent males are at a higher risk of reporting longtime use of over-the-counter drugs, compared with their female peers.
Early results of the study by Rebecca Vidourek, a UC assistant professor of health promotion, and Keith King, a University of Cincinnati professor of health promotion, will be presented on Oct. 29, at the 140th annual meeting of the American Public Health Association in San Francisco.
The study examined over-the-counter (OTC) drug use among 7th-12th grade students in 133 schools across Greater Cincinnati. The data was collected by the Coalition for a Drug Free Greater Cincinnati as part of the 2009-2010 Pride Survey on adolescent drug use in America. The survey was distributed to more than 54,000 students.
Early analysis found that 10 percent of the students reported abusing over-the-counter drugs. “Findings from this study highlight and underscore OTC drugs as an increasing and significant health issue affecting young people,” says Vidourek, who adds that commonly abused OTC medications include cough syrup containing Dextromethorphan (DXM), and decongestants. The researchers say that high rates of OTC use were also found among male and female junior high school students.
Vidourek says that OTC abuse can result in unintentional poisoning, seizures and physical and psychological addictions.
The researchers say that youth who reported involvement in positive activities, such as school clubs, sports, community and church organizations, were less likely to report abusing OTC medications. Teens more likely to report taking OTC drugs were also more likely to report that they had attended parties with the drugs or had friends who abused OTC drugs.

As crackdowns get tougher on alcohol, tobacco sales, and illicit drugs, there’s a growing trend among youth to turn to another source to get high: their parent’s medicine cabinet. A new University of Cincinnati study suggests adolescent males are at a higher risk of reporting longtime use of over-the-counter drugs, compared with their female peers.

Early results of the study by Rebecca Vidourek, a UC assistant professor of health promotion, and Keith King, a University of Cincinnati professor of health promotion, will be presented on Oct. 29, at the 140th annual meeting of the American Public Health Association in San Francisco.

54,000 Students Surveyed

The study examined over-the-counter (OTC) drug use among 7th-12th grade students in 133 schools across Greater Cincinnati. The data was collected by the Coalition for a Drug Free Greater Cincinnati as part of the 2009-2010 Pride Survey on adolescent drug use in America. The survey was distributed to more than 54,000 students.

Early analysis found that 10 percent of the students reported abusing over-the-counter drugs. “Findings from this study highlight and underscore OTC drugs as an increasing and significant health issue affecting young people,” says Vidourek, who adds that commonly abused OTC medications include cough syrup containing Dextromethorphan (DXM), and decongestants. The researchers say that high rates of OTC use were also found among male and female junior high school students.

Unintentional Poisoning, Addiction

Vidourek says that OTC abuse can result in unintentional poisoning, seizures and physical and psychological addictions.

The researchers say that youth who reported involvement in positive activities, such as school clubs, sports, community and church organizations, were less likely to report abusing OTC medications. Teens more likely to report taking OTC drugs were also more likely to report that they had attended parties with the drugs or had friends who abused OTC drugs.

November 5th, 2012  in Prescription Drugs No Comments »