Scientists Find Evidence For Asthma And Obesity Link

Main Category: Respiratory / Asthma
Also Included In: Obesity / Weight Loss / Fitness;  Allergy
Article Date: 24 Jul 2007 - 1:00 PDT

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Scientists at King's College London have discovered a protein that is known to increase appetite in cells which are closely associated with asthma. The research, which is funded by the Medical Research Council (MRC) and published online this week in the Proceedings of the National Academy of Sciences, could explain a suspected link between asthma and obesity.

There has been a considerable increase in asthma in recent years in a number of countries, including the UK, which coincides with a rise in the incidence of obesity. Scientists have been investigating whether the two conditions may be connected. Population surveys from both Europe and North America suggest a correlation between asthma and body mass index. Asthma is more common in obese people and obesity often precedes asthma, suggesting that increased weight is not simply a result of inactivity caused by asthma.

In this latest research, scientists from the MRC-Asthma UK Centre in Allergic Mechanisms of Asthma at King's College London and Imperial College London investigated the molecules produced by Th2 cells. These specialised cells of the immune system orchestrate inflammation in the lungs and contribute to the development of asthma.

The researchers demonstrated, for the first time, that in addition to producing proteins which cause asthma, the Th2 cells also produce a protein encoded by the gene PMCH (pro-melanin-concentrating hormone) which is known to increase appetite. The protein released into the circulation by Th2 cells in the asthmatic lung could stimulate the hypothalamus in the brain to enhance appetite. These findings may provide a mechanistic link between allergic inflammation, asthma and obesity.

Lead researcher, Dr David Cousins of King's College London, says: 'Our study provides evidence for a possible mechanism linking obesity and asthma. However, as people with asthma aren't always obese, we now plan to look at possible genetic polymorphisms, or variations, of PMCH to see the role they play.'

Professor Tak Lee, Director of the MRC-Asthma UK Centre, comments: 'Obesity and asthma are major health problems and clarifying the mechanisms responsible for their linkage provides important potential new opportunities for management of both conditions.'

Jenny Versnel, Executive Director of Research and Policy at Asthma UK says: 'We know that people who are obese often find it harder to manage their asthma symptoms and may even respond less well to their asthma treatments. This research is important because it could potentially help some people with asthma to gain more effective control of their condition.'

The study was funded by the Medical Research Council (MRC) with additional grants from Asthma UK, the Friends of Guy's and Guy's and St Thomas' Charity.

MRC-Asthma UK Centre in Allergic Mechanisms of Asthma

The Centre was set up in 2005 to tackle severe asthma caused by allergies. The Centre provides excellent prospects for disease prevention and control. It is a partnership between the MRC, Asthma UK, Imperial College London, King's College London and partner NHS Trusts. To find out more about the Centre's research please visit: http://www.asthma-allergy.ac.uk

The number of people with allergies in the UK has risen approximately three-fold in the last 20 years and one in three of us will develop an allergy at some point in our lives. The UK has among the highest rates of asthma in Europe and the cost is high - at least 12.7 million working days are lost to the condition annually and the Health Service spends around £889m on treating asthma every year.

King's College London

King's College London is the fourth oldest university in England with more than 13,700 undergraduates and nearly 5,600 graduate students in nine schools of study based at five London campuses. It is a member of the Russell Group: a coalition of the UK's major research-based universities. The College has had 24 of its subject-areas awarded the highest rating of 5* and 5 for research quality, demonstrating excellence at an international level, and it has recently received an excellent result in its audit by the Quality Assurance Agency.

King's has a particularly distinguished reputation in the humanities, law, international relations, medicine, nursing and the sciences, and has played a major role in many of the advances that have shaped modern life, such as the discovery of the structure of DNA. It is the largest centre for the education of healthcare professionals in Europe and is home to five Medical Research Council Centres - more than any other university.

King's is in the top group of UK universities for research earnings, with income from grants and contracts of more than £100 million, and has an annual turnover of more than £363 million.

http://www.asthma.org.uk