Research news in brief

Indigenous smokers decreasing, but deaths on the rise

There have been substantial reductions in smoking prevalence among Indigenous Australians. Smoking prevalence (including daily and less frequent) among Indigenous adults was 54.5% (95% CI, 51.7–57.4) in 1994 and 52.1% (95% CI, 49.9–54.3) in 2004–05, and the prevalence of daily smoking was 50.0% (95% CI, 47.9–52.2) in 2004–05 and 41.4% (95% CI, 39.1–43.6) in 2014–15. However, the lag between smoking and its associated cancer mortality means that the number of smoking deaths is likely to keep climbing in the near future, according to an article published in the Sax Institute’s Public Health Research and Practice journal. “We have seen significant decreases in smoking prevalence among Aboriginal and Torres Strait Islander adults, which will bring substantial health benefit in both the short and long term. However, we will continue to see the health consequences of tobacco use from up to 30 years ago – when smoking prevalence was at its peak – because of the delay between smoking and the onset of diseases such as lung cancer,” said Dr Raymond Lovett, from the National Centre for Epidemiology and Population Health at the Australian National University. “We are about to see the full effects of tobacco’s lethal legacy on Aboriginal and Torres Strait Islander peoples. While warning of these impacts, it is important to also note that there has been substantial progress in reducing tobacco use, particularly in the last decade, and this will not be reflected in current mortality patterns. The progress we have seen gives us a clear sign that we can further reduce smoking prevalence and improve Indigenous health. We need a continued comprehensive approach to tobacco control, and the incorporation of Indigenous leadership, long term investment and the provision of culturally appropriate materials and activities is critical to further reducing tobacco use.”

“Egg-timer” tests don’t predict fertility in older women

Among women of older reproductive age attempting to conceive naturally, biomarkers indicating diminished ovarian reserve compared with normal ovarian reserve were not associated with reduced fertility, according to a study published by JAMA. Collectively, anti-Müllerian hormone, early follicular phase follicle-stimulating hormone (FSH), and inhibin B have been referred to as biomarkers of ovarian reserve; however, the ability of these biomarkers to predict reproductive potential is uncertain. Between April 2008 and March 2016, researchers from the University of North Carolina conducted the Time to Conceive study, a prospective time-to-pregnancy cohort study, to determine the extent to which biomarkers of ovarian reserve were associated with reproductive potential. The study included women aged 30–44 years without a history of infertility who had been trying to conceive for 3 months or less. A total of 750 women provided a blood and urine sample and were included in the analysis. After adjusting for various factors, the researchers found that neither low serum anti-Müllerian hormone nor high FSH were associated with reduced fecundability (probability of conception in a given menstrual cycle) nor were they associated with a lower cumulative probability of conceiving by six or 12 cycles of pregnancy attempt. Urinary FSH and early follicular phase inhibin B levels were also not associated with fertility outcomes.

Ten times more overweight children globally than in 1975

Worldwide, there has been a more than tenfold increase in the number of obese children and adolescents aged 5–19 years in the past four decades, increasing from an estimated 5 million girls in 1975 to 50 million in 2016, and from 6 million to 74 million boys, according to a new global analysis of trends in child and adolescent obesity in 200 countries, published in The Lancet. Rates of child and adolescent obesity were highest (above 30%) in some islands in Polynesia, and were around 20% or higher in the USA and some countries in the Middle East and North Africa (eg, Egypt, Kuwait, Qatar and Saudi Arabia) and the Caribbean (eg, Bermuda and Puerto Rico). Overall, the global prevalence of child and adolescent obesity increased from 0.7% to 5.6% for girls, and from 0.9% to 7.8% for boys. Despite the increase in child and adolescent obesity, globally more children remain moderately or severely underweight than obese, with 75 million girls and 117 million boys moderately or severely underweight in 2016. Almost two-thirds of the world’s children and adolescents who are moderately or severely underweight lived in south Asia. The study, led by Imperial College London (UK) and the World Health Organization brought together data from 2416 studies involving 128.9 million participants worldwide, including 31.5 million children and adolescents aged 5–19 years, to estimate trends in body mass index (BMI) in 200 countries. Average child and adolescent BMI remains high in many high-income countries in North America and Europe, but trends have plateaued in recent years, even while average BMI among adults continues to rise. By contrast, the rise in average BMI has accelerated in many parts of Asia. In addition to the 124 million children and adolescents classified as obese in 2016, 213 million children and adolescents were in the overweight range.

“Baby talk” the same in any language

When talking with their young infants, parents instinctively use “baby talk”, a unique form of speech including exaggerated pitch contours and short, repetitive phrases. Now, researchers reporting in Current Biology have found another unique feature of the way mothers talk to their babies: they shift the timbre of their voice in a rather specific way. The findings hold true regardless of a mother’s native language. The researchers from Princeton University in the US recorded 12 English-speaking mothers while they played with and read to their 7- to 12-month-old infants. They also recorded those mothers while they spoke to another adult. After quantifying each mother’s unique vocal fingerprint using a concise measure of timbre, the researchers found that a computer could reliably tell the difference between infant- and adult-directed speech. In fact, using an approach called machine learning, the researchers found that a computer could learn to differentiate baby talk from normal speech based on just one second of speech data. The researchers verified that those differences couldn’t be explained by pitch or background noise. The next question was whether those differences would hold true in mothers speaking other languages. The researchers enlisted another group of 12 mothers who spoke nine different languages, including Spanish, Russian, Polish, Hungarian, German, French, Hebrew, Mandarin and Cantonese. Remarkably, they found that the timbre shift observed in English-speaking mothers was highly consistent across other languages from around the world. The researchers say the next step is to explore how the timbre shift helps infants in learning. They suspect that the unique timbre fingerprint could help babies learn to differentiate and direct their attention to their mother’s voice from the time they are born.

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