June 27, 2011 (San Diego) -- The number of adults with diabetes worldwide has more than doubled since 1980 to nearly 350 million, fueled in large part by an aging population and rising rates of obesity.
Diabetes rates have risen or at best remained flat in virtually every part of the world during the past three decades, according to international team of researchers led by Majid Ezzati, PhD, of Imperial College London, and Goodarz Danaei, MD, of Harvard School of Public Health in Boston.
The new figures are considerably higher than those of a recent study that estimated 285 million adults worldwide had diabetes.
Among high-income countries, diabetes rates were highest in the U.S., Greenland, Malta, New Zealand, and Spain. The Netherlands, Austria, and France boasted the lowest rates.
Despite the obesity epidemic in the U.K, the diabetes rate there was lower than that of most other high-income countries. Of 27 Western high-income countries, Britain had the fifth lowest diabetes rates among men and the 8th lowest rate for women.
The study was published online by The Lancet journal on June 25 to coincide with the annual meeting of the American Diabetes Association here.
No Improvement in Diabetes Rates Worldwide
High blood sugar and diabetes are responsible for about 3 million deaths globally each year, a number that will continue to rise as the number of people affected increases, according to the report.
For the study, the largest of its kind, the researchers analyzed fasting blood sugar (glucose) measurements from 2.7 million people aged 25 and older in 199 countries and territories. If a fasting blood glucose level was 126 mg/dL (7.0 mmol/L) or higher, a diagnosis of diabetes for study purposes was made.
From 1980 to 2008, the number of adults with diabetes rose from 153 million to 347 million, the report says. Seventy percent of the rise was because of population growth and aging, and the obesity epidemic accounted for much of the other 30%, Martin Tobias, MBBCh, of the Ministry of Health in Wellington, New Zealand, notes in a commentary accompanying the study.
"However, genetic factors associated with ethnic origin, fetal and early life nutritional status, diet quality, and physical activity might also affect [diabetes rates]," the authors write.
The percentage of adults with diabetes increased from 8.3% of men and 7.5% of women in 1980 to 9.8% of men and 9.2% of women in 2008.
Diabetes rates shot up the most in the Pacific Island nations; they now have the highest rates in the world, with about 16% of men and women affected. In the Marshall Islands, one in three women and one in four men has diabetes.
Why are rates so high in the Pacific islands? "It's really about diet and lifestyle," says Stuart Spencer, PhD, an editor at The Lancet who oversaw the peer-review process in which experts scrutinize the data prior to publication.
"They have a particularly high-caloric diet and a very sedentary lifestyle," he tells WebMD.
The regions with the lowest diabetes rates were sub-Saharan Africa, followed by East and Southeast Asia.