China Overtakes India as the Global Epicenter of the Diabetes Epidemic

Type 2 diabetes, mostly caused by a high-calorie diet and sedentary lifestyle, afflicts 92.4 million adults in China, a study published March 23 in the New England Journal of Medicine found. Earlier surveys calculated 43.2 million diabetics in the country, fewer than the 50.8 million that the Brussels-based International Diabetes Federation estimates are in India. 

A nationally representative sample of 46,239 adults, ages 20 years or older, from 14 provinces and municipalities in China, were included in this study. Subjects underwent glucose testing after an overnight fast, including fasting and 2-hour glucose measures, and oral glucose-tolerance testing. History of diabetes was based on self-report. World Health Organization diagnostic criteria were used to diagnose diabetes.

"This shows that the global burden of diabetes is far larger than previously estimated,'' David Whiting, a disease tracker with the federation, said in a statement. "It is a wake-up call for governments and policy makers to take action on diabetes.''

More than half of China's diabetics haven't been diagnosed, the study's authors said. That stands in the way of treatment for a disease that increases the risk of dying from stroke and heart attack, and reflects an unwanted consequence of the country's rapid urbanization

The China National Diabetes and Metabolic Disorders study is a cross-sectional study conducted from June 2007 through May 2008. The age-standardized prevalence of diabetes was 9.7% (10.6% for men and 8.8% for women), and for prediabetes the prevalence was 15.5% (16.1% for men and 14.9% for women). This accounts for an estimated 92.4 million adults with diabetes and 148.2 million adults with prediabetes. The prevalence of diabetes increases with age from 3.2% among adults 20-39 years of age to 20.4% for adults 60 years or older. Prevalence of diabetes also increases with increasing weight, from 4.5% for those with a body mass index (BMI) less than 18.5, to 18.5% for those with a BMI of 30 or greater. Prevalence of diabetes was higher among urban dwellers, as compared to those residing in rural communities (11.4% vs. 8.2%). However, the prevalence of prediabetes was higher among rural residents. The prevalence of isolated impaired glucose tolerance was higher than that of isolated impaired fasting glucose (11.0% vs. 3.2% for men and 10.9% vs. 2.2% for women). In multivariate models, factors associated with diabetes included male sex, older age, family history of diabetes, overweight or obesity, central obesity, increased heart rate, elevated systolic blood pressure, elevated serum triglycerides, and educational level below college.

The authors concluded that the observed prevalence of diabetes and prediabetes suggests a significant public health concern. Strategies for improving the diagnosis of prediabetes and diabetes and the prevention of diabetes are warranted.