Report on global cardiac risks: World gets fatter, but blood pressure goes down
Thursday, February 3, 2011; 8:59 PM
The whole world is getting fatter, except perhaps for the women of Italy and Singapore. Globally, blood pressure is slowly coming down. Cholesterol is falling in rich countries and rising in developing ones.
Those three variables are sketching a complicated and constantly changing picture of the world's risk for cardiovascular disease, which now kills more people than any other cause of death.
A massive project published Thursday is giving researchers and governments the clearest picture yet of trends of cardiac risk factors over the past generation, and hints at what may lie ahead.
"Our results show that overweight and obesity, high blood pressure and high cholesterol are no longer Western problems or problems of wealthy nations," said Majid Ezzati, the epidemiologist at Imperial College London who headed the project. "Their presence has shifted towards low- and middle-income countries, making them global problems."
Ezzati and more than a 100 collaborators used national data and surveys from 199 countries and regions to produce an epidemiological mosaic that reveals a big picture as well as telling details. The latter includes the heaviest group of people on Earth (men and women on the Pacific island of Nauru), the people with the lowest blood pressure (South Korean women), and those with the worst cholesterol (Icelandic men and women in Greenland).
The findings, published in three papers in the Lancet, also document considerable progress in recent decades, especially in the industrialized nations.
For example, the United States and Australia now have some of the lowest average blood pressures in the world. The United States, Canada, Sweden and Finland have also achieved large drops in average cholesterol in their populations in the past 20 years. At the same time, some of those places have seen steep increases in weight, as measured by body mass index, or BMI.
Ezzati hopes the information will be used to better understand which public health interventions have worked in recent decades.
"This effort is amazing, and the findings are very, very interesting," said Christopher Murray, a physician and biostatistician who heads the University of Washington's Institute for Health Metrics and Evaluation, as well as a former colleague of Ezzati's at Harvard University.
"Once you have something like this, you can shift the conversation to an entirely new level," Murray said. "You can start having a discussion of why countries have been more or less successful changing these risks, and that's a hugely important conversation."
Body weight, blood pressure and cholesterol are products of culture, diet and genetics. They raise the risk for heart attack and stroke independently, and to a lesser extent by affecting one another. For example, gaining weight often raises a person's blood pressure. It may also increase blood cholesterol, depending on whether the increased calories come from fat or other food sources.
Two other important risk factors - smoking and blood sugar - were not included in the analysis. A study of rising blood sugar and rates of diabetes worldwide is underway, Ezzati said.