In this Issue October 2003

Childhood Obesity and Asthma Risk

IPCRG - Fast Approaching 

HRT and Asthma 

Information about Asthma in Australia 

GPCE Melbourne 

Conference Diary 2003/4

Childhood Obesity and Asthma Risk

An association between being overweight and an increased risk of new-onset asthma in school-age children has been identified in a recent study from America. Being overweight was associated with an increased risk of new-onset asthma particularly in boys and in nonallergic children. Dr. Frank D. Gilliland and colleagues from the University of Southern California, Los Angeles noted that the parallel between the increase in childhood obesity and the epidemic increase in asthma (in the United States) may have public health significance.

In the longitudinal analysis, Dr Gilliland's group examined the association between obesity and new-onset asthma in 3,792 children. All the children were asthma-free at enrolment in the Children's Health Study.

New cases of physician-diagnosed asthma, height, weight, lung function, and risk factors for asthma were assessed annually at five school visits between 1993 and 1998. Incidence rates were calculated, and proportional hazards regression models were fitted to estimate the adjusted relative risks of new-onset asthma associated with percentile of body mass index (weight (kg)/height (m)²) and indicators of overweight (>85th body mass index percentile) and obesity (>95th body mass index percentile).

The researchers reported that 288 new cases of asthma were diagnosed during follow-up. Children who were overweight and obese had a higher risk of new-onset asthma (relative risk [RR] = 1.52 and RR = 1.60, respectively).

The risk of new-onset asthma associated with being overweight was increased among boys (RR = 2.06) compared with girls (RR = 1.25).

Non-allergic children had an increased risk of asthma associated with being overweight (RR = 1.77), but allergic children did not.

For the full article go to

Obesity and the Risk of Newly Diagnosed Asthma in School-age Children
(Am J Epidemiol 2003158:406-415)

IPCRG - Fast Approaching Apart from full registration to IPCRG 2nd World Conference - Respiratory Disease in Primary Care 'The Way Forward' 19 - 22 February 2004, there are a number of other options. Day registrants will be entitled to access to all Conference sessions on the nominated day, as well as morning tea, lunch and afternoon tea.

The Conference delegate’s kit will be provided and day registrants are also welcome to purchase tickets to Conference social events.

Student Registration is available to PhD students or GP Registrars, at a reduced rate. For the Student Registration rate, delegates must include verification from their supervisor or head of department in the appropriate section of the Registration Form.

Registrations are transferable to a colleague at no additional cost at any time prior to the Conference, provided the Conference Secretariat is advised in writing. For all the details please go to the conference website.

IPCRG Melbourne 2004

HRT and Asthma

Considerable attention has been placed on hormone replacement therapy (HRT) since the release of research results from The Million Women Study in the UK in August this year and from the USA Women's Health Initiative trial during 2002 and 2003. 

It now appears that HRT may also increase the risk of developing asthma or a respiratory allergy, according to research released at this month's congress of the European Respiratory Society held in Vienna.

Findings presented by a Norwegian team from Haraldpass Hospital and Bergen University were drawn from the very broad-ranging European Community Respiratory Health Survey study in which 16,190 women aged between 26 and 54, from northern Europe, were sent a questionnaire ten years ago and then contacted again between 1999 and 2002.

Results from the analysis of the responses sent in by 2,589 women aged over 45 suggest a possible link between female hormones and asthma or respiratory allergies. Women on HRT were 40 to 50% more likely to suffer from asthma or to exhibit asthma symptoms. The increased risk rose to 60% in the case of allergic asthma. Women on HRT were 30% more often affected by hay fever.

When non-smoking women in the study were reviewed, HRT use practically doubled the likelihood of having asthma or hay fever. 

The authors speculate that these findings may have an impact on the understanding of asthma and open up new avenues of research into its causes. However, it is possible that the results may have been influenced by the fact that a larger proportion of asthma-prone women using HRT were included.

Thus what cannot be excluded at this stage is a bias for women prone to asthma being more likely to have chosen to take HRT. The Norwegian research group  is about to undertake a controlled study to examine this question.  

The Norwegian study also considered the possible link between asthma and oral contraceptives on the basis of replies received from 6,512 women aged under 45. The findings showed that asthma and hay-fever increase by about a third among women who take oral contraceptives. However a causal link is yet to be established.

Useful Resource

Hormone Replacement Therapy Update

Information about Asthma in Australia

Comprehensive coverage of Australian asthma information is available in a report released earlier this month by the Australian Centre for Asthma Monitoring. The report brings together data from a wide range of sources to describe the number of people who have asthma, who receive various treatments for asthma, who have written Asthma Action Plans, and who visit their GP, are hospitalised or die due to asthma.   Range of Prevalence Data By international standards, the prevalence of asthma in Australia is high. More boys than girls have asthma but after teenage years, asthma is more common in women than in men. Interestingly, although women with asthma report their health being lesser than men with asthma, men tended to lose more days from work or school because of asthma.

Indigenous Australians have a higher prevalence than among non-Indigenous Australian adults, also with an increase in females over males. Overall, there is little variance in the  prevalence of asthma between cities, regional and remote areas.

Around one-third to one-half of adults with asthma have moderate or severe disease. People with asthma rated their health lower than people without asthma. Depression amongst people with asthma has a higher prevalence by comparison to people without asthma.

The majority of deaths due to asthma occur in people above the age of 65 years. For these older folk there is an increased risk of asthma death in winter. People from rural and remote areas or in more disadvantaged areas are more likely to die from asthma but this is also the case for deaths due to all causes.

People with asthma who were born overseas and do not speak English as a first language have a higher risk of death from asthma.

Smoking and Asthma

It is disappointing to learn that smoking in people with asthma was higher than the proportion of smokers among people without asthma. By contrast to the general population, more men with asthma in the 18 to 24 years age group were current smokers compared with women.

Young adults, adult men, and people living in outer regional and remote areas and in lower socioeconomic areas are least likely to have a written asthma action plan.

The most common type of asthma medication used in all age groups is reliever medication (short-acting beta agonists). Most reliever medication is given by puffers (metered dose inhalers) but a large amount (approximately one quarter) is supplied for use in nebulisers. Although the preventer medications (inhaled corticosteroids) are the second most commonly used asthma drug, there is evidence that not all people who should use them are doing so. Older people with asthma are more inclined to use their preventer medications than younger people with asthma.

Emergency Department and Hospital Treatments

Young children are the most likely age group to visit an Emergency Department for asthma, with boys outnumbering girls. In adulthood, it is more women who attend. People aged 65 years plus and young children are most likely to be admitted to hospital following an Emergency Department visit.

Children, particularly those under 5 years, have higher rates of hospitalisation and emergency department visits for asthma than adults. Asthma is more common in adult women but in childhood and the teens, asthma is more common in boys. 

The Australian Institute of Health and Welfare's comprehensive set of asthma data may be accessed at

Asthma in Australia

GPCE Melbourne

The National Asthma Council is presenting a series of paediatric asthma sessions entitled Diagnosis, management and the role of new therapies at the General Practitioner Conference & Exhibition (GPCE) in Melbourne scheduled for 7 - 9 November. Diagnosing and assessing asthma in children can be difficult.

The decision whether the asthma is episodic or persistent as well as determining level of severity can be challenging. The choice of which preventer medication best meets the needs of the child and their family is an important issue that the workshop will address along with diagnosis and severity assessment.

Particular emphasis will be placed on starting, trialling and/or changing medications. Potential medication side effects, best possible lung function and adherence to therapy, will also be reviewed as important considerations in good asthma management by experienced GP presenters.

GPCE specifically caters for the needs of general practitioners and along with the interactive and practical workshops, there will be a trade exhibition for equipment, computers, patient aids and pharmaceutical updates.

GPCE Melbourne

Conference Diary 2003/4

Submit brief conference/meeting details to the National Asthma Council for possible posting in our Conference Diary by email to nac@NationalAsthma.org.au.