China’s diabetes epidemic is worse than previously estimated -- much worse.
The most comprehensive nationwide survey for diabetes ever conducted in China shows 11.6 percent of adults, or 114 million, has the disease. The finding, published yesterday in the Journal of the American Medical Association, adds 22 million diabetics, or the population of Australia, to a 2007 estimate and means almost one in three diabetes sufferers globally is in China.
Chinese are developing the metabolic disease at a lower body mass index than Americans, the researchers found, meaning that changes in diet and physical activity stoked by rapid economic development are resulting in an earlier onset of the obesity-linked disease. The epidemic will worsen with 40 percent of 18-to-29-year-olds on the verge of developing diabetes, which increases the risk of stroke, heart attack and kidney failure.
“Diabetes in China has become a catastrophe,” said Paul Zimmet, honorary president of the International Diabetes Federation and director emeritus of the BakerIDI Heart and Diabetes Institute in Melbourne. “The booming economy in China has brought with it a medical problem which could bankrupt the health system. The big question is the capacity in China to deal with a health problem of such magnitude.”
Yesterday’s report is based on a survey of a nationally representative sample of 98,658 Chinese adults in 2010. A similar survey in 2007 pegged diabetes prevalence at 9.7 percent, or 92.4 million adults. The latest results means diabetes is now more common in China than in the U.S., where 11.3 percent of adults are diabetic.
The Brussels-based International Diabetes Federation estimates there are 371 million people worldwide with the disease, including 92.3 million in China.
The increase in the prevalence of diabetes in China, estimated at about 1 percent in 1980, has been “unparalleled globally,” Zimmet said in a telephone interview.
“China is now among the countries with the highest diabetes prevalence in Asia and has the largest absolute disease burden of diabetes in the world,” wrote authors led by Guang Ning in the laboratory for endocrine and metabolic diseases at the National Health and Family Planning Commission. “Poor nutrition in utero and early life combined with over-nutrition in later life may contribute to the accelerated epidemic of diabetes in China.”
The study incorporated measurements of glycated hemoglobin A, or HbA, into its diagnosis, adopting updated guidelines from the American Diabetes Association, in addition to tests used in earlier studies: glucose readings taken after patients fasted for a period of time, and a measurement of the amount of sugar in the blood two hours after patients consumed a sweet drink.
The added criteria may have partly contributed to the increased prevalence, Guang and colleagues wrote. The scientists estimate half of adults in China, or 493.4 million people, have higher-than-normal blood glucose levels, which put them in a pre-diabetic state.
“These data document a rapid increase in diabetes in the Chinese population,” according to the study’s authors, who include researchers from Beijing’s Chinese Center for Disease Control and Prevention and Johns Hopkins University in Maryland. “Diabetes may have reached an alert level in the Chinese general population, with the potential for a major epidemic of diabetes-related complications, including cardiovascular disease, stroke, and chronic kidney disease.”
Almost two-thirds of patients treated for diabetes didn’t have adequate blood-sugar control, the authors found. For every person in China diagnosed with diabetes, at least two more will be unaware they have it.
Study participants were weighed and measured to calculate their body mass index, or BMI, calculated as weight in kilograms divided by height in meters squared. For example, a 5-foot, 4-inch (1.63 meter) woman weighing 175 pounds (79 kilograms) has a BMI of 30. BMI of 30 or more is considered obese, while a BMI of 25 to 29.9 is considered overweight, according to the National Institutes of Health.
The average BMI in yesterday’s study was 23.7, compared with 28.7 in the U.S. population.
“Rapid lifestyle changes in China have caused rising trends in obesity, and that is now bringing out the abnormality of a people biologically more vulnerable to diabetes,” Juliana Chan, a professor of medicine and therapeutics at the Chinese University of Hong Kong, said in a telephone interview.
As in the rest of Asia, the burden of diabetes is falling disproportionately on the young and middle-aged, the authors said. Pre-diabetes was present in 40 percent of adults ages 18 to 29, and 47 percent among those 30 to 39.
“The alarmingly high figures for prediabetes are very scary,” said Chan, who wrote an editorial accompanying yesterday’s study and is also the founding director of the Chinese University of Hong Kong’s Institute of Diabetes and Obesity. “A lot of people think diabetes is a disease that mainly affects the elderly, but we have a very unhealthy young population that may lose their ability to work in the prime of their lives, and this would also have an impact on their families and on society,” Chan said.
China’s rising prevalence of diabetes has strained its health services and helped fuel a 20 percent-a-year growth in drug sales, stoking the need for newer and costlier medications from companies including Merck & Co., Novo Nordisk A/S and Sanofi.
China’s government is trying to fight the scourge by expanding basic medical coverage, buying more medicines in bulk to lower costs, and conducting a corruption probe of international drugmakers, including GlaxoSmithKline Plc.