Unique physiology key to diagnosing and treating diabetes in Asian populations
As the diabetes epidemic spreads worldwide, there is growing concern for Asian American populations, who are nearly twice as likely to develop diabetes, particularly type 2 diabetes. Compounding the problem, many of the standard ways to detect diabetes fail in people of Asian descent.
“The medical profession needs to be aware of and address the unique characteristics of this population,” said George L. King, M.D., Chief Scientific Officer at Joslin Diabetes Center and Professor of Medicine at Harvard Medical School (HMS). “Without this understanding, diabetes could be misdiagnosed or missed altogether.”
Dr. King was lead author of nine diabetes specialists nationwide who collaboratively wrote an article published in the May 2012 edition of Diabetes Care highlighting a comprehensive range of research findings presented at an international symposium held in Honolulu in September 2011.
The authors compiled extensive data on various groups that comprise the Asian American population, encompassing immigrants from numerous East Asian countries and those born in the United States. They also studied diabetes incidence in Native Hawaiians and Pacific Islanders.
Although there are large differences in immigration patterns and lifestyle adaptations to U.S. culture among these groups, common threads and new insights are emerging. Researchers are finding significant differences in how diabetes affects the body’s chemistry, how to view body weight, and why commonly used laboratory tests may not be reliable in Asian populations.
“Type 1 diabetes can be difficult to clinically differentiate from type 2 diabetes in Asians,” said Dr. William C. Hsu, M.D., who with Dr. King co-directs the Asian American Diabetes Initiative at Joslin. Dr. Hsu, an Assistant Professor of Medicine at HMS, was lead author of a team of 12 experts who wrote a second article published in the same edition of Diabetes Care. These authors focused on the pathophysiology, or the disease process, of diabetes.
China now has more people with diabetes than any other country, a new report shows, making it clear that the nation’s soaring economic growth is taking a toll on public health.
According to the report, more than 92 million adults in China have diabetes, and nearly 150 million more are well on their way to developing it. The disease is more common in people with large waistlines and in those who live in cities, the report indicates.
“For every person in the world with HIV there are three people in China with diabetes,” said David Whiting, an epidemiologist with the International Diabetes Federation, who was not involved in the research.
The Federation projected last year that some 435 million people would have diabetes by 2030. “With this new study, we’re going to have to rerun our estimate,” Whiting told Reuters Health.
The report, published Thursday in the New England Journal of Medicine, is based on a nationally representative sample of more than 46,000 people who were tested for diabetes.
Type 1 diabetes is relatively rare in Asians, with incidence five to 10 times lower than in people of European descent. But diagnosing the disease is more difficult because genetic markers and blood factors generally associated with type 1 diabetes are present in only 30 percent of patients of Asian descent. In other words, simply relying on conventional tests would lead to misdiagnosis of a large percentage of Asians who have type 1 diabetes. More research is needed to learn what other biological factors in Asians patients lead to the destruction of insulin-making beta cells, resulting in type 1 diabetes. Lab tests then could be developed to detect these specific factors.
Fast food ‘fuelling Asia diabetes boom’
Many Vietnamese have diabetes but are unaware of it - and the condition is spreading fast in South East Asia, scientists have warned.
A study by Australian and Vietnamese scientists found about 11% of men and 12% of women in Vietnam’s Ho Chi Minh City had undiagnosed type 2 diabetes.
This was in addition to the 4% of people who had been diagnosed.
The scientists, from Australia’s Garvan Institute of Medical Research, blamed changing lifestyles and fast food.
“Dietary patterns have been changing dramatically in Vietnam in recent years, particularly in the cities as they become more Westernised,” said Professor Tuan Nguyen of the Sydney-based institute.
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The researchers from Australia’s Garvan Institute of Medical Research blamed changing lifestyles and fast food for the rise in cases of diabetes. For a full report on diabetes in Vietnam see Elizabeth Snouffer’s report.
Type 2 diabetes is the most common form of diabetes in Asian Americans, with prevalence of diagnosed cases in recent years jumping from approximately 1 or 2 percent to 10 percent today, compared with 6 percent in the general population. Many others are undiagnosed or at risk, falling into the “pre-diabetes” category. In type 2 diabetes, the pancreas produces insulin but not enough, or the body’s cells resist its effect. A risk factor commonly associated with type 2 diabetes is excess weight, often measured by calculating the body mass index (BMI).
But for Asian Americans with type 2 diabetes, the average BMI is between 24 and 25, well within the normal BMI range (19?) for the general population.
“The BMI in Asian patients can be misleading. They can look quite skinny,” Dr. Hsu said. “Instead, we’re learning that a better indicator of type 2 diabetes risk in Asians is fat deposits at the waistline.” More research is needed to understand how visceral fat contributes to the onset of type 2 diabetes. If detected in the pre-diabetes stage, the disease often can be prevented.
THE IMPACT OF TYPE 2 DIABETES
Being diagnosed with type 2 diabetes can be a frightening and overwhelming experience, and it is common to have questions about why it developed, what it means for long-term health, and how it will affect everyday life. It is important to try educate yourself as soon as possible. There is a great deal you can do as a patient to affect your diabetes. The sooner you accept it, and care for it, the sooner it will become a part of your normal life.
In order to educate yourself, you should talk to your doctor or nurse about resources that are available for medical as well as psychological support. This may include group classes, meetings with a nutritionist, social worker, or nurse educator, and other educational resources such as books, websites, or magazines.
Despite the risks associated with type 2 diabetes, most people can lead their normal active lives. Today given all the wonderful new medications and tools at our disposal, you can live a good life with diabetes, as long as you take care of yourself.
To diagnose diabetes, a commonly used tool- the fasting plasma glucose- fails to detect abnormal glucose tolerance in many Asian Americans. The authors recommend the oral glucose tolerance test, which although more cumbersome to do, has greater sensitivity and reliability in Asian populations.
Per diabetes complications, physicians need be aware that Asian Americans with diabetes tend to have a lower incidence of cardiovascular disease but higher rates of end-stage renal disease. These patients need to be monitored and treated accordingly.