Three papers published Online First by The Lancet show that the worldwide prevalence of obesity has nearly doubled since 1980. Meanwhile high-income countries have shown impressive reductions in mean blood pressure and cholesterol levels, with some countries doing much better than others. The Articles show that every region and country has its own story to tell. The papers were written by Prof Majid Ezzati, Imperial College London, UK; Dr Goodarz Danaei, Harvard School of Public Health, Boston, MA, USA, and colleagues.
The study shows that in 2008, more than one in ten of the world's adult population was obese, with women more likely to be obese (BMI above 30 kg/m2) than men. An estimated 205 million men and 297 million adult women were obese – a total of more than half a billion adults worldwide.
The percentage of the world's population with uncontrolled hypertension (high blood pressure), fell modestly between 1980 and 2008. However, because of population growth and ageing, the actual number of people with uncontrolled hypertension rose from 600 million in 1980 to nearly 1 billion in 2008. High-income countries achieved large reductions in uncontrolled hypertension, with the most impressive progress seen in women in Australasia and men in North America. Uncontrolled hypertension is defined as a systolic blood pressure higher than 140 mmHg or diastolic blood pressure higher than 90 mmHg.
Average levels of total blood cholesterol fell in Western countries of North America, Australasia and Europe, but increased in East and Southeast Asia and the Pacific region.
Professor Majid Ezzati*, the senior author of the study from the School of Public Health at Imperial College London, said: "Our results show that overweight and obesity, high blood pressure and high cholesterol are no longer Western problems or problems of wealthy nations. Their presence has shifted towards low and middle income countries, making them global problems."
Beyond global trends, the studies reveal how different countries compare in terms of each risk factor. The results show that:
Professor Ezzati says*: "It's heartening that many countries have successfully reduced blood pressure and cholesterol despite rising BMI. Improved screening and treatment probably helped to lower these risk factors in high-income countries, as did using less salt and healthier, unsaturated fats.
"The findings are an opportunity to implement policies that lead to healthier diets, especially lower salt intake, at all levels of economic development, as well as looking at how we improve detection and control through the primary healthcare system. Policies and targets for cardiovascular risk factors should get special attention at the High-level Meeting of the United Nations General Assembly on Non-Communicable Diseases in September 2011."
Dr. Goodarz Danaei says*: "This is the first time that anyone has tried to estimate trends in these major risk factors in every country in the world. The amount of data we collected is unprecedented and vast, and allows us to draw robust conclusions."
Dr. Gretchen Stevens, WHO, Switzerland, adds*: "Our study helps track the obesity problem in individual countries and regions. We know that changes in diet and in physical activity have contributed to the worldwide rise in obesity, but it remains unclear which policies would effectively reduce obesity. We need to identify, implement, and rigorously evaluate policy interventions aimed at reversing the trends, or limiting their harmful effects."
In a linked Comment, Professor Salim Yusuf and Dr Sonia S Anand, Population Health Research Institute, McMaster University, Hamilton, ON, Canada, say that the contrasting patterns of obesity vs blood pressure and total cholesterol in these findings suggest that directly controlling blood pressure, total cholesterol, and smoking will lead to rapid and substantial reductions in cardiovascular disease rates even while obesity and (type 2) diabetes might be increasing.
They say: "Therefore focusing on controlling these three risk factors (blood pressure, total cholesterol, and smoking) will rapidly and to a large extent reduce cardiovascular disease globally within a few years, while we continue our efforts to stem and ultimately reverse the tide of obesity, which will need more prolonged and societal-based interventions over decades."
To contact Prof Ezzati, please contact Colin Smith, Media Officer, Imperial College London. T) +44(0)20 7594 6712 / (Out of hours) +44(0)7803 886 248 E) email@example.com /firstname.lastname@example.org
Professor Salim Yusuf and Dr Sonia S Anand, Population Health Research Institute, McMaster University, Hamilton, ON, Canada. T) +1 905 297 3781 E) email@example.com
For full BMI paper see: http://press.thelancet.com/bmi.pdf
For a chart showing country by country BMI trends 1980 to 2008, see: http://press.thelancet.com/countrybmi.pdf
For full blood pressure paper see: http://press.thelancet.com/bp.pdf
For a chart showing country by country systolic blood pressure trends from 1980 to 2008, see: http://press.thelancet.com/countrybp.pdf
For full cholesterol paper see: http://press.thelancet.com/cholest.pdf
For a chart showing country by country systolic blood pressure trends from 1980 to 2008, see: http://press.thelancet.com/countrychol.pdf
Notes to editors: extra quote from Prof Ezzati: "Trends in the UK, USA, Canada and Australia have plenty of unexpected findings: These countries all have done poorly in terms of controlling overweight and obesity, with US having the worst performance of any wealthy nation. But American men have fared better than men in Australia, Canada, and the UK in lowering their blood pressure, and in fact better than most other wealthy countries. Among women, Australia clearly outperformed the other 3 in blood pressure control. When it comes to controlling cholesterol, the UK has had the largest reductions of these 4 countries but its cholesterol is still higher than the other 3 because it had very high levels in 1980."
The work forms part of the Global Burden of Diseases, Injuries and Risk Factors Study, which is supported by the Bill and Melinda Gates Foundation. The study also received funding from the World Health Organization (WHO).
*Quotes taken directly from authors, not found in text of Articles
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