Research news in brief

Young people less satisfied with their GP experience

New data from the Australian Bureau of Statistics (ABS) show that around 5.2 million people aged 15–34 years saw a GP in 2017–18, yet only two in three (67%) felt that the GP always listened carefully to them, compared with over four in five people (83%) aged 65 years and over. Results of the 2017–18 ABS Patient Experience Survey showed that young people were less satisfied with their GP experience than patients aged 65 years and over. Young people aged 15–34 years were also less likely to feel that the GP always showed them respect (75% compared with 87% of older patients) and less likely to feel that the GP always spent enough time with them (70% compared with 84% of older patients). Director of Health Statistics at the ABS, Louise Gates said: “Further results from the survey show that, as expected, young people aged 15–34 years generally used health services less often than older people, with 77% seeing a GP, 26% seeing a medical specialist, and 10% being admitted to hospital. This compared with 96%, 57% cent and 20% of people aged 65 years and over. However, those aged 15–34 years were more likely to have seen an after-hours GP (10%) [compared with] those aged 65 years and over (5%). At the same time, people aged 15–34 years were more likely to delay seeing a medical specialist (27% compared with 9%) and nearly twice as likely to delay seeing a dental professional (35% compared with 20%) than those aged 65 years and over. In particular, younger people were more likely to delay or not use health services due to cost (13% compared with 2% of people aged 65 years and over). Similarly, 21% delayed or did not see a dental professional due to cost compared with 9% of people aged 65 years and over,” Ms Gates said.

Evidence for low carbohydrate diet in maintaining weight loss

A low carbohydrate diet could help people maintain their weight loss by increasing the number of calories burned, according to US research published in The BMJ. The researchers say this effect may improve the success of obesity treatment, especially among people with high insulin secretion (insulin level 30 minutes after consuming a standard amount of glucose). It is well known that energy expenditure declines with weight loss, as the body adapts by slowing metabolism and burning fewer calories, often resulting in weight regain. But little is known about how dietary composition influences this adaptive response over the long term. One theory (known as the carbohydrate-insulin model) is that recent increases in the consumption of processed, high glycaemic load foods trigger hormonal changes that increase hunger and make people more likely to gain weight. Researchers at Boston Children’s Hospital compared the effects of diets varying in carbohydrate to fat ratio on energy expenditure over a 20-week period. The trial involved 234 overweight adults aged 18–65 years with a body mass index of 25 or higher who took part in an initial run-in weight loss diet for about 10 weeks. After 12% (within 2%) weight loss on the run-in diet, participants were then randomly assigned to one of three test diets according to carbohydrate content (high, 60%, n = 54; moderate, 40%, n = 53; or low, 20%, n = 57) for 20 weeks. Each participant was provided with fully prepared meals with a similar protein and fat content. The researchers then tracked participants’ weight and measured energy expenditure to compare how the different groups burned calories at the same weight. After adjusting for potentially influential factors, they found that over the 20 weeks, total energy expenditure was significantly greater in participants on the low carbohydrate diet compared with the high carbohydrate diet. Participants on the low carbohydrate diet burned 209 to 278 kilocalories a day more than those on the high carbohydrate diet – or about 50–70 kilocalories a day increase for every 10% decrease in the contribution of carbohydrate to total energy intake. In those with the highest insulin secretion at the start of the study, the difference in total energy expenditure between the low and high carbohydrate diets was even greater – up to 478 kilocalories a day, consistent with the carbohydrate-insulin model. If this effect persisted “it would translate into an estimated 10 kg weight loss after 3 years, assuming no change in calorie intake,” wrote the authors.

Online survey shows how we use music as a sleep aid

Many individuals use music in the hope that it fights sleep difficulties, according to a UK study published in PLOS ONE. There is a lack of systematic data on how widely music is used, why people opt for music as a sleep aid, or what music works. To address this gap in knowledge, the researchers investigated music as a sleep aid within the general public via an online survey that scored musicality, sleep habits, and open-text responses on what music helps sleep and why. In total, 62% of the 651 respondents reported that they use music to help them sleep, describing 14 musical genres comprising 545 artists. Even respondents who don’t have sleep disorders use music in their everyday lives to help improve the quality of their sleep experiences, and younger people with higher musical engagement are significantly more likely to use music to aid sleep. Respondents believe that music both stimulates sleep and blocks an internal or external stimulus that would otherwise disrupt sleep. The study relied on self-reported answers and could only investigate respondents’ beliefs about how music helped them sleep, rather than drawing conclusions about music’s physiological and psychological effects. The participants also self-selected for the study, so it may have been biased towards music users. Nonetheless, the study provides initial evidence that many people use diverse types of music in the belief that it helps them sleep. The authors add: “The largest ever survey of everyday use of music for sleep reveals multiple pathways to effect that go far beyond relaxation; these include auditory masking, habit, passion for music, and mental distraction. This work offers new understanding into the complex motivations that drive people to reach for music as a sleep aid and the reasons why so many find it effective.”

Dengue and Zika in flavivirus one-two punch

Two new studies provide evidence that previous dengue infection in pregnant mothers may lead to increased severity of Zika in babies, and that previous Zika infection in mice mothers may increase severity of dengue infection in their pups. The research, published in Cell Host and Microbe, supports that maternally acquired antibodies for one virus can assist infection by the other by a process unique to flaviviruses. Dengue and Zika are both flaviviruses, which use RNA as their genetic material and usually spread to humans by hitching rides on mosquitoes. Both diseases concentrate in tropical and subtropical areas where the Aedes mosquito thrives. While at first dengue causes a relatively mild fever, subsequent infections raise the risk of developing a deadly haemorrhagic form. Only one dengue vaccine exists for use in limited cases. Zika virus infection during pregnancy causes mild to moderate fever symptoms in the mother and can cause brain defects such as microcephaly in the fetus. No approved Zika vaccines exist as of today. In the first study, researchers examined how dengue antibodies affect the ability of Zika virus to infect the placenta. When they introduced dengue antibodies and the Zika virus to donated human placental tissue, the dengue antibodies bound to Zika due to similarities in the proteins that envelope the virus. However, the dengue antibodies failed to neutralise the Zika virus, instead transporting the still pathogenic form into cells of the placenta. In the second study, researchers showed that Zika antibodies can also enhance dengue. They found that mouse pups born to mothers with circulating Zika antibodies were less likely to contract Zika, but more likely to die from dengue, than those with Zika-naive mothers. When the researchers studied the mice’s blood, they saw that the mothers had passed their Zika antibodies down to their pups. Mirroring the first study, the maternally inherited Zika antibodies bound to the dengue virus but did not inactivate it. More studies are needed to uncover whether other flaviviruses, such as West Nile and yellow fever, also increase the offspring’s vulnerability to each other. As mosquitoes carrying these viruses spread farther and the threat of infection rises, the researchers believe there is a need to develop pan-flaviviral vaccines that would be effective against both dengue and Zika.

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