By Denise Williams | News & Views

The modern focus on healthcare disparities and inequities stretches far and wide, touching a multitude of underserved groups – Asian Americans, among them. The issue also traverses the spectrum of healthcare services, including the specialty of cardiac rehabilitation. Still, one might not expect these two trajectories to intersect, given the generally favorable heart health observed in this subset of the U.S. population. But, in this case, one would be wrong.

Sketched in broad strokes, the cardiovascular picture for Asian-American adults portrays a people who enjoy a seemingly favored status. Overall, they are less likely to be obese or overweight, less likely to have hypertension, less likely to smoke and less likely to suffer and/or die from heart disease than their White counterparts. Subsequently, notes Dr. Wen-Chih “Hank” Wu, MD, MPH, “it’s often not publicized that cardiac disease is still a risk for Asian-American adults. It’s also not  taught enough, at the public health/health promotion level, that this can be a problem.”

The other flaw with that snapshot, according to Dr. Wu, a professor of medicine and epidemiology at Brown University, is that it lumps the Asian-American patient population together as a single group. In actuality, he explains, the demographic is made up of various subgroups differentiated by uniquely distinct cultural behaviors, dietary habits and genetic compositions. So, while the common perception of cardiovascular risk for Asian Americans is in fact true for some Asian Americans, it isn’t true for all Asian Americans.

The Same … But Different – And Why It Matters

The cardiovascular profile of East Asian Americans – people from China, Japan and Korea – is not the same, for example, as that of Vietnamese Americans, which differs from that of Hawaiian-Pacific Islanders, and so on down the line. Dr. Wu, who also serves as director of Rhode Island’s Lifespan Cardiovascular Institute and Treasurer on the AACVPR Board of Directors, identifies Asian Indian Americans and Filipino Americans as having greater risk of heart disease and mortality due to heart disease compared with the Asian-American community in general. And Pacific Islanders, who also stand out as a higher-risk Asian-American subgroup, are just as vulnerable to heart attack – if not more so – than White Americans.

BMI

From a clinical perspective, these differences demand differential approaches to care. Consider, Dr. Wu proposes, the matter of body mass index (BMI). Used as a gauge of healthy/unhealthy body size, BMI signifies “overweight” when the reading reaches 25 kg/m2 and “obese” when it tops 30 kg/m2. “We have only one overall metric for what is considered normal weight measuring BMI,” Dr. Wu notes, “and that estimate is derived mostly from White adults.” Meanwhile, he reports, evidence actually suggests that the point – the level of BMI – at which blood pressure, blood sugar and cholesterol start to climb is actually much lower for Asian Americans, at 23.7. “All of the cardiovascular risk factors that track very closely with body weight start to go higher at lower cut-offs, specifically for East Asian Americans,” Dr. Wu points out. There’s plenty of buzz in the medical and research communities about how ideal BMI can and should be stratified according to ethnicity and race, but Dr. Wu acknowledges that it’s a complicated undertaking. Not only does the conversation spill over into discussions of race and ethnicity as a cultural and social construct and raise questions about the social determinants of health issues, it’s also a challenge in the context of increasingly multi-racial ancestry. Imagine how unmanageable the landscape might become if a different barometer was in place for the myriad combinations of genetic makeup. “It’s hard to say,” Dr. Wu suspects, “‘that because you’re 30% Asian, 40% European and 40% African American, that this is going to be your ideal BMI.’”

While genetics actually predispose some Asian Americans to heavier weight – think American Samoa, Wu hints – the upside is that the vast majority of cardiac risk, 80% or more, can be addressed through changes in diet and behavior, just like with other ethnic groups. But even so, differences between Asian-American subgroups underscore the need to approach them differently.

Food, Famine, and Exercise

Dr. Wu offers a few examples that highlight the differences underpinning the various Asian-American groups:

• Among the first wave of Japanese immigrants to the United States, heart disease risk remained on par with that observed on mainland Japan. Starting with the very first generation born and raised in America, however, the incidence of heart disease and related mortality increased compared with the mainland.
• A diabetes and high blood pressure intervention in American Samoa by the Providence Group, of which Wu is a member, explored the overall high BMI in this island population. While so-called metabolic thrift and other genetic factors were implicated, researchers also attributed Samoan heaviness to the change of lifestyle (e.g., tendency towards a more sedentary behavior) and a high-fat diet (e.g., use of coconut-derived products as a cooking staple).
• The experience of famine in some countries also has an impact on future generations, studies show. The Providence Group has reported on how the offspring of survivors of the Great Famine in China during the 1950s are more prone to hypertension, diabetes and obesity because of the parental experience of famine and starvation.

It’s clear from these examples, Dr. Wu observes, how eating habits and other backgrounds and behaviors vary greatly from one Asian-American subgroup to the next, and how they influence health outcomes. At the same time, he acknowledges that there also are shared characteristics. For instance, Dr. Wu points to a language barrier that sometimes is not erased even after years in the United States. Additionally, he shares how Asian Americans don’t like to “bother people,” so they might say that they understand instructions when they really have questions. Also, Dr. Wu continues, there is resistance across the Asian-American population to the concept of food and exercise as medicine. “Historically and culturally, to pick and choose what kind of food you eat is considered a luxury,” he explains. “In terms of exercise, the gender differences and expectations are very different. There’s a cultural barrier for Asian women to exercise in general and especially outside of the household.” Breaking down these barriers will mean aiming interventions not only at the patient level but at the entire family, Dr. Wu says.

The Cardiac Rehab Takeaways

In summary, Dr. Wu emphasizes three key points for the cardiac rehab community:                         

• First, it’s imperative to remember that Asian Americans constitute a heterogeneous group and that the risk of heart disease and cardiovascular risk factors are not uniform among the various subpopulations. With that in mind, cardiac rehab professionals should pay special attention to enrollees who are Pacific-Islanders, Asian Indian Americans and Filipino Americans, whose heart attack risk is higher than the risk of Asian-American adults as a whole.
• Second, also keep in mind that the criteria for obesity that applies to White adults do not necessarily apply to Asian Americans. Calibrating BMI to more accurately reflect metabolic differences will allow for more timely and appropriate care.
• Third, the unique ethnic and cultural differences of Asian Americans should be reflected in the counseling and education they receive in pursuit of lifestyle changes. Just because there’s a behavior change recommendation that’s appropriate for one ethnic group, it might not be suitable at all to another. Therefore, cardiac rehab practitioners must make it a point to understand the Asian subgroup they’re working with, recognize the potential cultural and behavioral idiosyncrasies of the different factions – especially their diet and perception of exercise – and tailor their messaging accordingly.