Babies whose growth is at either extreme in the womb, either very small or very large, are at greater risk of developing autism, a new study has revealed.

It is the first time that a clear link has been made between babies who grow to above average size at birth and risk of Autism Spectrum Disorder and follows from a study of more than 40,000 child health records in Sweden.

The research, led by The University of Manchester, also confirmed earlier research which reported that premature and poorly grown, low weight babies appear more susceptible to the condition.

Autism affects how individuals interact with the world and with other people and there is no known cure. Researchers believe it has origins in both genetic and environmental causes.

Professor Kathryn Abel, from the University`s Centre for Women`s Mental Health and Institute of Brain, Behaviour and Mental Health, who led the research said: "The processes that leads to ASD probably begin during fetal life; signs of the disorder can occur as early as three years of age. Fetal growth is influenced by genetic and non-genetic factors. A detailed understanding of how fetal growth is controlled and the ways in which it is associated with ASD are therefore important if we are to advance the search for cures.

Researchers looked at data from the Stockholm Youth Cohort in Sweden, where early ultrasound dating provides detailed weights of the baby`s progression in pregnancy. Infants and children then also take part in structured clinical assessments of their social, motor, language and cognitive abilities.

The cohort contained records of 589,114 children aged 0-17 in Sweden between 2001 and 2007. Certain child data was removed, including children too young to have a diagnosis for ASD, adopted children and non Swedish or Stockholm County residents, children not born in Sweden and twins.

From the remaining available data, researchers found 4,283 young people with autism and 36,588 who did not have the condition and who acted as the control.

The study found that bigger babies who were born weighing over 4.5kg (or 9lb 14) showed a higher incidence of autism, as did smaller infants who were born weighing less than 2.5kg (5.5lb).

A baby who had poor fetal growth would therefore have a 63 percent greater risk of developing autism compared to normally grown babies. A baby who was large at birth would have a 60 percent greater risk. This effect was independent of whether or not the baby was born pre or post term.

Professor Abel added: "We think that this increase in risk associated with extreme abnormal growth of the fetus shows that something is going wrong during development, possibly with the function of the placenta.

"Anything which encourages abnormalities of development and growth is likely to also affect development of the baby`s brain. Risk appeared particularly high in those babies where they were growing poorly and continued in utero until after 40 weeks. This may be because these infants were exposed the longest to unhealthy conditions within the mother`s womb," she stated.
The research was published in The American Journal of Psychiatry this month.

Brigham Young University chemistry professor Emily Bates has identified mutations in a gene that makes people more susceptible to migraine headaches.

The study is the first demonstration of a genetic cause for the common migraine and is an important step in the search for a cure.

"I had migraines really frequently and severely. I would lose my vision, vomit uncontrollably - it would wipe out an entire day," Bates said.

She decided then as a high school student that she was going to work on migraines, that she was going to figure them out and help find a cure.

After earning a Ph.D. in genetics from Harvard, Bates did post-doctoral research with a team of geneticists led by Louis Ptacek at University of California San Francisco`s medical school.

This gene hunting party worked with two families that appeared to have a dominantly inherited form of the affliction.

The researchers zeroed in on genetic mutations these families had in common - mutations that affect production of a protein known as casein kinase delta.

To test whether this was a cause or a coincidence, Bates designed an experiment to determine whether the same genetic trait led to migraine symptoms in mice.

"All sensations become amplified with migraines, including touch, heat, sound and light," Bates, who continued work on the project when she took a position at BYU in 2009, said.

The researchers observed this heightened sensitivity in the migraine mice in very subtle ways - from the warmth of a tiny light and the pressure of a single hair-like filament.

The findings are set to be published in Science Translational Medicine.

A new research from Johns Hopkins has found that blood levels of vitamin D or so-called "sunshine vitamin" higher than the top of the range suggested by the Institute of Medicine confer no additional benefit.

This finding, combined with results of a previous study by the same group noting potential harm from higher vitamin D levels in healthy people, has urged investigators to prescribe caution.

"Healthy people have been popping these pills, but they should not continue taking vitamin D supplements unchecked," said study leader Muhammad Amer, M.D., M.H.S., an assistant professor in the Division of General Internal Medicine at the Johns Hopkins University School of Medicine.

"At a certain point, more vitamin D no longer confers any survival benefit, so taking these expensive supplements is at best a waste of money," he added.

Amer stresses that there are some groups of people - elderly, postmenopausal women, and people with kidney disease - who do benefit from higher blood levels of a vitamin vital to bone health. Such groups may need to take supplements.

Amer and Rehan Qayyum, M.D., M.H.S., also of Johns Hopkins, conducted a review of data from more than 10,000 participants in the National Health and Nutrition Examination Survey (NHANES) from 2001 to 2004. They matched those data with mortality data from the National Death Index through Dec. 2006.

When they looked at deaths from all causes and cardiovascular disease specifically, those with blood levels of 21 nanograms per milliliter of 25-Hydroxyvitamin D - at the top of the range that the IOM considers "adequate" and at the low end of "normal" - cut their risk of death in half. Above 21 nanograms per milliliters, the data suggest that the protective effect appears to wear off.

The primary source of vitamin D is the sun, and although it is found naturally in very few foods, commercially sold milk is usually fortified with it.

Amer said as people spend more and more time indoors and slather their bodies with sunscreen when outdoors, concern is rising that many are vitamin D-deficient. But he stated that there is no set amount of supplementation that can bring someone up to 21 nanograms per milliliter because the way people process vitamins varies.

In research published in January 2012 in the American Journal of Cardiology, Amer and Qayyum found that increasing levels of vitamin D in the blood are linked with lower levels of a popular marker for cardiovascular inflammation - c-reactive protein (also known as CRP).

Beyond blood levels of 21 nanograms per milliliter, any additional increase in vitamin D was associated with an increase in CRP, a factor linked to stiffening of the blood vessels and an increased risk of cardiovascular problems.

The team`s unpublished research also suggests a link between excess vitamin D and elevated homocysteine levels, another danger sign for cardiovascular disease.

People should consult with their doctors, Amer said, before starting vitamin D supplements and should have their blood levels checked.

The researchers described their work in an article published online in the American Journal of Medicine .

When exposed to secondhand smoke at home, teenage girls tend to have lower levels of the "good" form of cholesterol that reduces heart disease risk, according to a recent study.

High-density lipoproteins (HDL) pick up excess cholesterol in the blood stream and take it to the liver where it can be broken down. Unlike low-density lipoproteins that can create a waxy build-up that blocks blood vessels, HDL cholesterol can play a key role in combatting heart disease risk.

"In our study, we found 17-year-old girls raised in households where passive smoking occurred were more likely to experience declines in HDL cholesterol levels," said the study`s lead author, Chi Le-Ha, MD, of the University of Western Australia.

"Secondhand smoke did not have the same impact on teenage boys of the same age, which suggests passive smoking exposure may be more harmful to girls. Considering cardiovascular disease is the leading cause of death in women in the western world, this is a serious concern," the researcher added.

Researchers studied a longitudinal birth cohort of 1,057 adolescents who were born between 1989 and 1992 in Perth, Australia. The study gathered information about smoking in the household beginning at 18 weeks gestation and leading up to when the children turned 17. During that time, 48 percent of the participants were exposed to secondhand smoke at home. Blood tests were performed to measure the teenagers` cholesterol levels.

"The findings indicate childhood passive smoke exposure may be a more significant cardiovascular risk factor for women than men," Le-Ha said.

The study has been accepted for publication in The Endocrine Society`s Journal of Clinical Endocrinology and Metabolism (JCEM).