The American Diabetes Association (ADA) has lowered the Body Mass Index (BMI) cut-off for Asian Americans at risk of developing Type 2 diabetes. Now, all Asian American adults with a BMI ≥ 23 kg/m2 should be tested for diabetes, according to the ADA. This new policy is part of an extensive update to the ADA's diabetes treatment guidelines for 2015.
Screening for diabetes is a major concern for health care providers, but studies have reported that the standard BMI cut-offs for being overweight (BMI ≥ 25 kg/m2) and obese (BMI ≥ 30 kg/m2) aren't serving well as indicators for Asian Americans at risk for diabetes.1
The ADA's updated BMI cut-off for Asian Americans is prudent, though perhaps overdue. Asian patients diagnosed with diabetes have reported BMIs well below 25 kg/m2 or have not even been technically overweight.2
These recommendations have been incorporated into many publications and guidelines, so the recommendations from the ADA are late in coming, but welcome nonetheless. They are congruent with the effort to identify people at risk sooner in the progression of disease, from initial weight gain, to adiposopathy (also known as sick fat), to prediabetes, to diabetes.
The Asian American population is expected to more than double to 34.4 million people by 2060.3,4 The term "Asian," as defined by the US Census Bureau, is a blanket term for multiple geographic regions, including the Far East, Southeast Asia, and the Indian subcontinent, which all contain various countries.
The ADA conducted a review of US-based studies that investigated how BMI scores could serve as an indicator for Asian Americans at risk for diabetes. While Asian Americans are a very heterogeneous population, containing many different ethnicities, basic patterns in the data still were evident: Asian Americans were more at risk for diabetes than non-Hispanic whites and were being diagnosed at much lower BMIs than the norm.
In addition to focusing on BMI, don't neglect the importance of monitoring waist circumference, a measurement that helps to indicate how much visceral fat a person has.
Increasing body weight is a significant risk factor for diabetes, but the quantity and location of body fat is even more important.5-7 Compared to non-Hispanic whites, male and female Asians have different body compositions, being more likely to have a higher percentage of fat at a lower BMI score.8 Asians also are known to develop visceral fat instead of peripheral fat.
Visceral fat builds up around the waist, causing bigger bellies and increases in waist circumference. Visceral fat is a major risk factor for Type 2 diabetes, insulin resistance, and other health complications.9
In 2014, we published updated recommendations for overweight and obesity management with the American Association of Clinical Endocrinologists (AACE). These guidelines recognize that not only BMI but also waist circumference vary in Asian populations.
I would emphasize that risk is not just determined by BMI thresholds, but also by waist circumference thresholds. And the combination of both is a much more significant predictor of risk.