May 2010 – Helen Jaques

Hosting big sports events might not benefit the local population

May 24, 2010 5 Comments

Hosting an international sporting event like the Olympic Games or the Commonwealth Games is an expensive business. The London 2012 Olympic and Paralympic Games, for example, will cost a total of £9.35bn, equivalent to £150 for every man, woman, and child in the United Kingdom.

Such costs are generally justified in terms of collateral benefits for the population of the host city, both during the event and for years after – the so called “legacy” of the event.

However, Researchers in Glasgow – host of the 2014 Commonwealth Games – have searched through the sparse published and unpublished research on the topic and found little overall evidence that major multi-sport events provide health or socioeconomic benefits for the population of the host city.

They looked for studies on the long term effects of major sports events held between between 1978 and 2008 and came across very few papers – only 54 poor quality studies.

Five studies looked at the benefits on the host population in terms of health; more specifically, rates of suicide, paediatric health service demand, presentations for asthma in children (two studies), and problems related to illicit drug use. Overall, the data did not show a clear cut negative or positive health impact of major multi-sport events.

Of the studies that looked at whether sports participation in the population was affected, one found a decrease in the Manchester after the 2002 Commonwealth Games, whereas another reported upward trend in sports participation from the early 1980s to 1994 in association with the 1992 Olympic Games in Barcelona, Spain.

More studies – 18 in total – looked at whether big sports events improved economic factors, which in turn might have a positive effect on the health of the population; for example, by giving people the cash flow to pay their dentist’s fees or make healthy eating choices. But again the overall effect was unclear. Most studies did associate big sports events with an increase in economic growth and employment, but the studies often used lots of estimated data and didn’t collect the data very long after the event, so are hardly water tight. The more robust studies weren’t any more conclusive when looked at collectively – inflation increased in Barcelona and Atlanta in the run up to hosting the Olympic Games, but not in Sydney.

“The available evidence does not refute expectations of a legacy, positive or negative, but it does establish that very little is known about the impacts of previous large multi-sport events and, therefore, the possible impacts of future events,” conclude the authors. “This contrasts with official documentation used recently to promote such events,” they add curtly.

However, we Brits may not be throwing money down the drain by financing the next Olympic Games. As the authors of this study acknowledge, the research on the legacy benefits of major multi-sports events is patchy to say the least, hence why they were unable to draw any clear positive or negative conclusion. The London 2012 Olympics will be the first for which long term health and socioeconomic impacts will be explicitly measured, so should hopefully clear up whether or not hosting these big events really does benefit the local population.

Editorialist Mike Weed isn’t so sure that this effort will give us the evidence we need though, as he feels the measures being used for the 2012 event are not detailed enough. “The risk for the UK population is not that we will not get the benefits we want for our £150 a head investment in London 2012, but that there will be no robust evidence of what we have paid for,” he says.

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McCartney G et al. (2010). The health and socioeconomic impacts of major multi-sport events: systematic review (1978-2008). BMJ 340. DOI: 10.1136/bmj.c2369

Children

Mary Poppins was right: a spoonful of sugar DOES help the medicine go down

May 19, 2010 2 Comments

A new study has found that giving children up to one year old a sweet solution before jabs reduces the pain of the immunisation, providing a scientific basis for Mary Poppins’ maxim that “a spoonful of sugar helps the medicine go down.”

The meta-analysis looked at fourteen randomised controlled trials that assessed the effects of oral sucrose, glucose, or another sweet solution compared with placebo (water) or no treatment during 1674 injections in infants aged 1-12 months.

Thirteen (92.9%) of the trials found that the sweet solutions reduced various behavioural indicators of pain, such as crying, during and after immunisation compared with placebo. In the fourteenth study, the effects of a sucrose solution were only evident during a single immunisation and not for the second and third injections. The pain reduction was largely seen after the procedure had been completed rather than during the procedure.

Although the sweet solutions reduced behavioural signs of pain, they had less of an effect on physiological signs: none of the studies found that glucose or sucrose solutions reduced heart rate in infants during immunisation. On the other hand, one study found that infants who received a glucose solution (and were allowed to suck on a dummy) had lower levels of cortisol, the stress hormone,in their saliva after immunisation than infants who received water (with or without a dummy).

When data from the studies were pooled, sweet solutions were found to reduce the incidence of crying by 20%, the proportion of crying time by 10%, and the duration of crying time by 12 seconds compared with placebo.

The 14 studies all used different volumes and concentrations of sucrose and glucose, so the authors were not able to determine an optimal dose of sweet solution to be used in infants during immunisation. However, the findings did imply that more concentrated sugar solutions – for example, 50% sucrose in water – are more effective.

The authors recommend that “sucrose or glucose along with other recommended physical or psychological pain reduction strategies, such as non-nutritive sucking [e.g. using a dummy], breast feeding or effective means of distraction, should be consistently utilised for immunisation.”

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Harrison D et al. (2010) Efficacy of sweet solutions for analgesia in infants between 1 and 12 months of age: a systematic review. Archives of Disease in Childhood DOI: 10.1136/adc.2009.174227

Public health

Hookah smokers more likely to use marijuana or other illicit drugs

May 17, 2010 No Comments

Young people who smoke tobacco through a water pipe – also known as a hookah, shisha, or goza – are more likely to use illicit drugs than their non-smoking contemporaries, according to a study of young Canadians. Most notably, hookah smokers were much more likely to smoke marijuana: 74% of water-pipe users reported marijuana use, compared with 35% of non-users.

A hookah or shisha comprises an upright device with a small platform where tobacco, often flavoured, is burned, a metal body, a base half-filled with water, and a tube with a mouthpiece for inhaling.

Smoking tobacco using water pipes is an old Arabic tradition that is becoming more popular in the Western world, with an estimated 40% of US college students and 38% of British university students having ever used a hookah.

The rise in popularity is thought to be linked to the perception that smoking tobacco through a water pipe is harmless. However, water pipe smoke may contain greater amounts of tar and heavy metals, such as lead, than cigarette smoke and has been linked to lung cancer, heart disease, and infectious diseases.

In this study, the authors posted questionnaires to 1,208 18-24 year olds who lived in the Montreal area of Canada, 878 (73%) of whom responded and 871 (72%) of whom were included in the analyses.

A total of 204 participants (23%) reported having smoked tobacco using a water pipe in the past year. Among these water-pipe users, 78% smoked water-pipes less than once per month, 19% smoked 1-3 times per month, and 3% smoked 1-6 times per week. None used a water pipe every day.

Individuals who had used a hookah were younger, more likely to be male and not living with their parents, and had a higher household income than those who hadn’t, leading the authors to suggest that “Water-pipe users may represent an advantaged group of young people with the leisure time, resources, and opportunity to use water-pipes.” So hookah smokers are nice middle class kids with too much time on their hands then?

Compared with people who hadn’t used a water pipe in the previous year, those who had were more likely to have also used cigarettes and other tobacco products like chewing tobacco or snus and to have used alcohol, including having up to five or more drinks on one occasion (i.e. to a binge drinking level). Interestingly, a third of water-pipe users had not smoked cigarettes in the past year, perhaps using a hookah as a perceived “healthier” alternative.

Water-pipe users were more likely to have used marijuana (74% vs 35%) or other illicit drugs like speed or cocaine (33% vs 11%) in the past year, suggesting perhaps that smoking tobacco through a water pipe may act as a “gateway” to using more harmful substances. Nevertheless, the authors point out that the design of their study means no cause and effect inferences can be drawn between using a hookah and illicit drug use.
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Dugas E et al. (2010) Water-Pipe Smoking Among North American Youths. Pediatrics DOI: 10.1542/peds.2009-2335

Fertility and reproduction

The pill could lower sex drive in young women

May 13, 2010 3 Comments

This month marks the 50th anniversary of the contraceptive pill, first approved by the FDA in 1960 and now the choice of contraception for more than 100 million women worldwide. By uncoupling sex from pregnancy, oral hormonal contraceptives finally allowed women to become agents of their own bodies.

Life isn’t all rosy on the pill though. The various different formulations have been associated with all sorts of side effects, the most issue being venous thromboembolism.

Now new research from female medical students in Germany has found that hormonal contraception such as the pill could also reduce sex drive.

Several previous studies have suggested that oral contraception might affect female sexual function, but overall the evidence as to whether they have a positive or negative effect is pretty mixed.

The researchers behind this study emailed female students at six medical schools in Germany and asked them to fill in an online questionnaire about their sexual function in the past four weeks and their usual means of contraception over the past six months. A total of 1,086 women (15-20%) aged mostly under 25 years responded.

A total of 87.4% of women had used contraception in the previous 6 months, most of whom had used oral hormonal contraception (69.5%).

About a third (32.4%) of participants were considered at high risk of sexual dysfunction. However, this figure actually isn’t too bad compared with a previous study of 78 female medical students in the US, which found that 63% were at high risk of sexual dysfunction. Other larger studies put the rate at a more conservative 38% in Germany and 43% in the States.

When the sexual dysfunction data were analysed on the basis of single usual form of contraception (1,046 participants), women who used oral hormonal contraception or non-oral hormonal contraception were most at risk of having sexual dysfunction. Oral hormonal contraception was associated in particular with low desire and arousal compared with other forms of contraception and no contraception.

The authors suggest that the link between oral hormonal contraceptives and sexual dysfunction may be because oral contraceptives decrease the circulating levels of testosterone, “which is needed to (i) stimulate sexual desire and (ii) regulate genital blood flow and the structural and functional integrity of the genitals.”

Interestingly, smoking was associated with a lower risk of sexual dysfunction than not smoking, an effect the authors hilariously suggest might be down to the fact that “smokers might have greater ability to enjoy themselves.”

“This is a very important research investigation,” stated Dr Irwin Goldstein, Editor-in-Chief of Journal of Sexual Medicine, which published this study. “There are hundreds of millions of women, in particular young women at the beginning of their sexual lives, who regularly use hormonal contraception for many years. The irony is that these women are provided a medication that enables freedom from reproductive worries but these same women are not provided information that there are significant adverse sexual effects that may ensue. Agents that interfere with the hormonal milieu of women may adversely affect their sexual lives.”

Don’t panic yet though, this study isn’t the final word and has various shortcomings, not least the possibly of participation bias – where women with perceived sexual problems might have felt more inclined to participate than women with no sexual problems – and reporting bias – where participants might have overestimated or underestimated the scale of their sexual difficulties.

Furthermore, the low response rate to the questionnaire (15-20%) means the study population probably isn’t a great reflection of all the female medical students at the eight schools studied, much less students worldwide, and, as the authors say, their stats suggest that “the factors considered can only explain a small fraction of the variability of total [female sexual function] scores.”

As it is, hormonal forms of contraception – both oral and non-oral – are the most successful forms around. So I wouldn’t throw away your pills just yet.

Put off oral hormonal contraceptives? Nature Medicine has an article on the 50th anniversary of the pill that highlights some possible alternatives under development.

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Wallwiener C et al. (2010) Prevalence of Sexual Dysfunction and Impact of Contraception in Female German Medical Students. Journal of Sexual Medicine DOI: 10.1111/j.1743-6109.2010.01742.x

Cancer

Viagra could help women too, but not how you think…

May 10, 2010 2 Comments

Since first coming on the market in 1998, the erectile dysfunction drug Viagra has improved the sex lives of countless men. Now new research has suggested that phosphodiesterase 5 (PDE5) inhibitors like Viagra could also help women – but not how you think.

Researchers in California have shown that sildenafil (Viagra) and a similar drug called vardenafil can improve the delivery of the chemotherapeutic drug Herceptin (trastuzumab) in women with breast cancer that has spread to the brain. Their studies in mice have found that PDE5 inhibitors help Herceptin cross the blood vessels of brain tumours into the heart of the cancer, thus improving the therapeutic efficacy of Herceptin for brain metastases from primary tumors.

Although only about 22,000 patients in the US are diagnosed with a primary brain tumor each year, nearly 10 times that many people develop brain tumors from cancers that began elsewhere in the body. For example, one study found that 36% of women receiving Herceptin for breast cancer developed brain metastases.

These secondary brain tumours are very hard to treat thanks to the fact that chemotherapy drugs can’t cross the walls of the tumour’s blood vessels – the blood-brain tumor barrier – and into the cancer. “Mother Nature created this barrier to protect our brains from dangerous substances, but here we need to get through the barrier to deliver the drugs, and that’s a problem,” said study author Julia Y Ljubimova, a research scientist at the Cedars-Sinai Maxine Dunitz Neurosurgical Institute in Los Angeles. This means that drugs that can kill the primary tumour in the breast or lung aren’t effective on secondary tumours in the brain.

Ljubimova and her colleagues looked at the effects of PDE5 inhibitors on drug delivery in mice whose brains had been implanted with human lung and breast tumors. Oral administration of vardenafil to such mice doubled the uptake of Herceptin by brain tumours. Importantly, vardenafil had no effect on the uptake of Herceptin in neighbouring healthy tissue, an unfortunate effect of many chemotherapy drugs that is responsible for making cancer patients feel so awful and lose their hair.

Furthermore, combination treatment of mice with vardenafil and Herceptin increased the survival time of these mice by 20% compared with those that received Herceptin only. This effect was only seen in mice whose brain tumours were positive for HER2, the growth factor targeted by Herceptin, and not those that were HER negative, indicating that the survival benefit was indeed due to an increase in the amount of Herceptin reaching the tumors.

“Now that we’ve demonstrated that big molecules can cross the blood-brain tumor barrier, we’re going to continue this strategy with other big molecule drugs, such as nanomedicine drugs” said Ljubimova. “This opens a new world for brain tumor treatments.”

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Hu J et al. (2010) Phosphodiesterase Type 5 Inhibitors Increase Herceptin Transport and Treatment Efficacy in Mouse Metastatic Brain Tumor Models. PLoS ONE 5 (4). DOI: 10.1371/journal.pone.0010108