The well-known cardiovascular protective effect of education only occurs in high-income countries (HICs), according to a new report from the REACH registry appearing in Circulation. A striking finding was that highly educated women were more likely than their less educated counterparts to smoke in both affluent countries and less affluent countries. The authors point out that “studies linking socioeconomic status to cardiovascular outcomes in HICs cannot be extrapolated to LMICs (low- or middle-income countries), particularly for women.” Overall, educational attainment was protective in HICs, but not in LMICs, against obesity, smoking, and hypertension.
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Here is the AHA press release:
Study highlights:
- The incidence of heart disease, stroke and certain risk factors decreased as educational levels increased in high-income countries, but not in low-and middle-income countries.
- Among women, the most educated in low-and middle-income countries had a slight increase in the incidence of heart attack and stroke.
- Among all other groups, heart disease declined as education increased, with highly educated men in high-income countries showing the lowest level of disease.
American Heart Association Rapid Access Journal Report:
Higher education predicts better cardiovascular health outcomes in high-income countries, but not in low- and middle-income countries
DALLAS, Sept. 7, 2010 — In one of the first international studies to compare the link between formal education and heart disease and stroke, the incidence of these diseases and certain risk factors decreased as educational levels increased in high-income countries, but not in low- and middle-income countries.
Researchers — who reported their study in Circulation: Journal of the American Heart Association — also found that smoking rates unexpectedly increased with greater education level among women in high-income and low-and middle-income regions. Furthermore, highly educated women in low-and-middle-income countries had a slight increase in the incidence of fatal and nonfatal heart attack and stroke. Among all other groups, heart disease declined as education increased, with highly educated men in high-income countries showing the lowest level of disease.
In general, low- and middle-income countries have not achieved a significant degree of industrialization relative to their populations, and often have a medium to low standard of living. There is a strong correlation between low income and high population growth.
“We can’t simply take studies that are conducted in high-income countries, particularly as they relate to socioeconomic status and health outcomes, and extrapolate them to low- and middle-income countries,” said Abhinav Goyal, M.D., M.H.S., lead author of the study and assistant professor of epidemiology and medicine (cardiology) at Emory Rollins School of Public Health and Emory School of Medicine in Atlanta, Ga. “We need dedicated studies in those settings.”
Smoking, a major contributor to heart disease and stroke, typically declines as formal education rises. But investigators found that nearly half of the highly educated women from high-income countries smoked, compared with 35 percent for those with the least amount of schooling. Likewise, low- and middle-income countries had higher smoking rates among the most educated women (21 percent versus 14 percent among the least educated).
For men, smoking rates were virtually the same across educational groups in low- and middle-income countries. In affluent countries, however, the most educated men smoked less than did men with the fewest years of formal education (66 percent versus 75 percent).
“We can’t assume that just because certain groups are more educated than others that they’re going to have healthier lifestyles,” Goyal said. “Everyone needs to be educated about the risk of heart disease in particular, and counseled to adopt healthy lifestyles and to quit smoking.”
For the two-year study, investigators assessed 61,332 patients from 44 countries with diagnosed heart disease or stroke, or several risk factors, including smoking, high blood pressure, clogged blood vessels and obesity. Thirty-six percent of participants were female, 64 percent were male, and the average age was 69.Investigators used years of formal education and previous classifications of income by world region to divide participants by socioeconomic level.
As the leading causes of death worldwide, heart disease and stroke killed an estimated 17.5 million people in 2005, according to the latest statistics from the World Health Organization. More than 80 percent of these deaths were in low- and middle-income countries, highlighting the critical need for more research in these areas.
“We are facing an increase in the epidemic of cardiovascular disease in countries with developing economies,” said Sidney Smith, M.D., study co-author and professor of medicine and director of the Center for Cardiovascular Science and Medicine in the University of North Carolina School of Medicine. “What this paper suggests is that things may be different in these countries. If we’re really going to develop strategies that are effective, we need to understand much better what those differences are.”
Co-authors are Deepak L. Bhatt, M.D., M.P.H.; Ph. Gabriel Steg, M.D.; Bernard J. Gersh, M.D.; Mark J. Alberts, M.D.; E. Magnus Ohman, M.D.; Ramón Corbalán, M.D.; Kim A. Eagle, M.D.; Efrain Gaxiola, M.D.; Runlin Gao, M.D.; Shinya Goto, M.D., Ph.D.; Ralph B. D’Agostino, Ph.D.; Robert M. Califf, M.D.; and Peter W.F. Wilson, M.D. Author disclosures are on the manuscript.
Sanofi-aventis, Bristol-Myers Squibb and the Waksman Foundation funded the study.
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In a way, this finding is not surprising. The effect of education is influenced by other factors.
For instance, in high income countries, even people with relatively little education have enough disposable income to both smoke and lead sedentary lives. But in lower income countries, people with less education are less likely to be able to afford to smoke… and they are more likely to walk, bicycle and have manual labor jobs.
China is a good example. Beijing used to be filled with bicycles. Now it is clogged with cars. Education and incomes rose… while urban planning, public policy and personal choices replaced clean and active bicycling with polluting and inactive driving.
These facts of daily life shape people’s behaviors more powerfully than education about how we “should” behave.
I’d be interested to see an analysis that took into account threshold levels of income that are associated with smoking… as well as the associations between income as physical activity.