Unique physiology makes it hard to diagnose diabetes in Asians

[Guest guest]

Unique Physiology Key to Diagnosing and Treating Diabetes in Asian

Populations

9-May-2012

May 2012 - 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 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. 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.

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.

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 (19-25) 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.

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.

Per treatments for diabetes, the authors cited the need for more studies:

" The unique features of diabetes pathophysiology within this very

heterogeneous population may indicate a need for different treatment

guidelines. " Insulin dosing, oral medications and lifestyle factors such as

exercise and nutrition should be enfolded into a diabetes care program

tailored to individuals, families and cultural practices.

The team of experts at Joslin's Asian Diabetes Initiative has found that

educational materials are most effective when published in both the Asian

language and English, allowing younger and older generations to communicate

fluidly. Joslin also has developed multilingual websites.

Community-based education programs, which also have proved to be highly

effective, need to be expanded. And in national data collection, it is

important to include Asian groups as subsets of the general population, with

culturally appropriate methods incorporated into the design of surveys.

" While there is much to be gained from ethnically sensitive care, these

considerations are only a starting point, " Dr. Hsu said. " Ultimately, all

diabetes care needs to be tailored to the individual. That's the direction

that medicine is going, and all populations will benefit. "

Source: Joslin Diabetes Center