Researchers at Imperial College London, Harvard School of Public Health, and worldwide collaborators analyzed data from a total of 199 countries on the prevalence of risk factors related to heart and circulatory disease between 1980 and 2008.
Their analysis showed that a country's income was correlated with the population's average blood pressure, cholesterol as well as BMI in 1980. There was no association between national income and blood pressure in men in 2008, but blood pressure was higher in poorer countries for women.
While BMI was still lowest in the poorest countries, it was higher in middle-income countries than the wealthiest countries. Cholesterol remained higher in higher-income Western countries. Fasting blood sugar, which is linked to diabetes, was only weakly related with income and affluence, but correlated with obesity.
Meanwhile, the study also found that BMI has consistently been related to the proportion of the population living in cities. This might imply that urban lifestyle might be playing a critical role in the obesity epidemics both now and in the past.
What worrying the researchers is that developing countries will be facing a rising numbers of obesity, diabetes and hypertension should the current trend continues, and developed nations will continue to be confronted with an epidemic of diabetes and high cholesterol.
To change the relationship between national income and blood pressure, it is necessary to improve the diagnosis and treatment of hypertension in wealthier countries, coupled with changes in diet and lifestyle.
Reason why high cholesterol is still associated with national wealth is probably the cost of meat and other animal products are relatively high. As such, lower income nations should encourage their people to choose unsaturated fats over saturated fats to avoid the problems that richer countries already have.
Developing countries should strive to replicate the success that developed countries have had in lowering blood pressure by improving primary health care services, lowering salt intake and making fresh fruit and vegetables more available.
Cost imposed by circulatory and heart diseases could be huge on healthcare systems in high- and middle-income countries, hence redirecting some of these resources to prevention might save a lot in the long run.