Professor Jean Claude Mbanya, President, International Diabetes Federation, comments on the findings and implications of a new study in China published by the New England Journal of Medicine .
China now the country with the largest number of people with diabetes
Previous estimates in the International Diabetes Federation’s (IDF) Diabetes Atlas Fourth Edition  - published in October 2009 - put the number of people with diabetes in China at 43.2 million, based on the best evidence available at the time.
Now, it would appear China has overtaken India and become the global epicentre of the diabetes epidemic with 92.4 million adults with the disease.
Some of the difference between the old and new estimates for China may be due to differences in methodology. However, the new figures certainly reflect a rapid increase in the prevalence of diabetes over recent years.
Due to the new study, we expect the projected estimates of the number of people with diabetes in the year 2030 will be close to half a billion.
Why the large disparity between the old and new estimates; implications for policy maker
It is not entirely surprising that the new study estimates there are nearly twice as many people in China with diabetes than previously thought. IDF based its 2009 figures for China on the findings of a study by Gu et al in 2003 - the best data available at the time. It is important to note that IDF uses a conservative modelling approach. When new studies are conducted around the world, we see a leap in diabetes figures.
We welcome the findings of this new study published in the New England Journal of Medicine. The methodology is good as it uses a large, well-constructed sample and the gold standard method for detecting diabetes, the Oral Glucose Tolerance Test, as recommended by the World Health Organization.
This shows that the global burden of diabetes is far larger than previously estimated. It is a wake-up call for governments and policy-makers to take action on diabetes - a major public health problem.
Level of public awareness of diabetes in China
Around the world, there are many people with diabetes who remain undiagnosed. In some poorer countries, 80% to 90% of people with diabetes are undiagnosed; while even in high-income countries 30% may be undiagnosed.
In China, 60.7% are undiagnosed, and this is likely to result from the combination of poor public awareness and limited opportunities for diagnosis.
People often have type 2 diabetes for a long time before it is diagnosed. For many people, the diagnosis comes when they make contact with the health system for other reasons (for example when admitted to hospital with a heart attack). The longer people are undiagnosed, the more likely it is that their blood glucose will be poorly controlled and therefore their risk of developing diabetes complications, that can affect their sight, kidneys or lead to amputations or stroke, will be higher.
In China, there is room to increase the proportion of people who are diagnosed, but this needs to be backed up with sufficient resources to manage and treat larger numbers of people with diabetes. Diagnosing more cases without being able to increase the amount of care available will do little to improve the lives of people with diabetes.
How China's health system is equipped to handle diabetes; challenges and importance of education, primary healthcare reform
Through our interactions with Chinese medical authorities, we know that China is committed to primary healthcare reform (ie. dealing with diabetes and other diseases at the grassroots level such as clinics, general practitioners etc.) and interdisciplinary education and care (ie. healthcare delivered to people with diabetes by a team of professionals from different disciplines, eg. education, nutrition, endocrinology etc.).
There are excellent interdisciplinary programmes being provided in some parts of China such as Beijing and Shanghai. However, the sheer number of people with diabetes presents a great challenge.
A landmark study in China in 1997 proved that prevention works. The Da Qing study showed that increasing physical activity and improving diet reduces the incidence of type 2 diabetes. Recently, a follow-up study has shown that the effects continued to last after 20 years.
The challenge now for China - and all countries – is to find ways to help people to be more physically active and improve their diets. This requires an integrated approach, and involves other sectors outside of health, for example those that influence urban design and food legislation.
IDF’s member association in China, the Chinese Diabetes Society, is working with Chinese health officials to promote education and self-management of the condition, which is vital in dealing with diabetes.
How lifestyle diseases are overtaking infectious diseases in developing countries; economic impacts; steps to redress the situation
In countries such as China and India, which are showing rapid economic development, we are seeing mass urbanisation, changing diets and increasingly sedentary lifestyles. These factors greatly increase one’s risk of developing type 2 diabetes.
Evidence shows that the burden of diabetes continues to shift to low and middle-income countries, making it very much a development issue. The World Health Organization predicts India and China will respectively lose US$236.6 billion and US$557.7 billion of national income to diabetes and cardiovascular disease between 2005 and 2015.
According to IDF estimates, the latest prevalence figures emerging from China will mean healthcare expenditure on diabetes in the country this year will increase by at least US$1.9 billion, reaching a total of US$ 6.9 billion.
Policy-makers need to integrate plans for the prevention of diabetes into national health systems. Countries have to find ways to develop economically in a way that is not harmful to health. This requires creative thinking and legislation that helps people to be physically active and eat appropriately. People need to be supported and encouraged to make healthy choices, and the environment needs to be developed in a way that supports this.
For more information, contact:
International Diabetes Federation
Email: email@example.com 
Note to editors:
The International Diabetes Federation (IDF) is the global advocate for more than 285 million people with diabetes worldwide. It represents over 200 diabetes associations in more than 160 countries. Its mission is to promote diabetes care, prevention and a cure worldwide. IDF is in official relations with the World Health Organization and associated with the United Nations Department of Public Information. Visit www.idf.org  for more information.