Cardiovascular disease kills some 17 million people each year, and about 80 percent of these deaths occur in the developing world. Not every country is affected equally. But when scientists study populations in different countries, their results are influenced by a mix of culture, environment, and genetics.
A new study tries to sort out some of those factors.
A closer look at four ethnic groups
Researcher Maria Chiu and her colleagues studied the prevalence of heart disease and stroke in four ethnic groups: whites, Chinese, South Asians and blacks all living in Ontario province, Canada. They used data collected in national and community health surveys from 1996 to 2007.
Although all were living in the same place and had access to universal healthcare, Chiu found striking differences. Her analysis showed that more than one in 20 South Asians suffered from heart diseases, compared to around only one in 30 among the Chinese and black populations.
Chiu notes that those three ethnic and racial groups comprise 60 percent of the world population. "So it is important that we understand how these groups are, in terms of their heart health. And this study in Canada allows us to do that in a more controlled environment where everyone is living within the same physical environment as well as having access to universal healthcare."
Chiu also looked at the prevalence of eight risk factors for heart disease and stroke, including smoking, obesity, high blood pressure and diabetes. These also differed significantly from group to group. For instance, whites were three times more likely to smoke than Chinese and South Asians. And South Asians and blacks were twice as likely to suffer from diabetes as members of the other two groups.
"Our study did not look at the causes for these risk factors being high and low," Chiu explains. "It was important that we reported that they were high and low, and the next step would be to understanding why."
Implications for policy makers
Chiu says her research raises important questions. And the answers will likely draw from a combination of factors, including genetic predisposition, cultural factors and socioeconomic status.
Chiu also said her research has important planning implications for policy makers. "For example, if we know from the study that diabetes is twice as prevalent among the blacks and the South Asian populations, and we know that the South Asian and the black populations are going to double or triple within the next 20 years, then our projections for our health care needs in the future, which currently are predominantly based on the white population, will be grossly underestimating our needs."
Maria Chiu's research is published in the Canadian Medical Association Journal.