People with higher levels of education face a reduced risk of heart disease and stroke in rich countries but a new study suggests that this association does not hold good for low and middle-income nations.

Men with higher levels of education living in rich countries like the United States have the lowest level of cardiovascular diseases, but the same results do not hold good in the poorer countries, the researchers in Atlanta have said.

The study, published in the latest issue of the medical daily Circulation, suggests that the research team found nearly half of the highly educated women in high-income groups smoked and thereby increased their risk levels to heart disease. However, in the poorer nations, only about 35 percent of women with low levels of education actually indulged in smoking.

In the middle and low-income countries, the researchers observed that 21 percent of the highly education women were smokers as against just about 14 percent among those who had lower levels of education.

A press statement issued by the American Heart Association quotes Dr. Abhinav Goyal, an assistant professor of epidemiology and medicine (cardiology) at Emory Rollins School of Public Health and Emory School of Medicine in Atlanta, to say that studies conducted across high income countries need not always hold good across the world.

"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. We need dedicated studies in those settings," says Goyal who is the lead author of the two year study.

The research team conducted surveys across a sample size of more than 61,000 people from 44 countries who were diagnosed with heart disease, stroke or other forms of cardiovascular disease risk factors like high blood pressure, obesity, clogged blood vessels and smoking.

Among men in high-income countries, 66 percent of those with the most education smoked, compared to 75 percent of those with the least education. In low and middle-income countries, smoking rates were similar for men of all education levels, the study found.