Large percentages of Mexican adults have risk factors for heart disease and stroke -- suggesting, researchers say, that without intervention, the nation's rate of cardiovascular disease will continue the climb it began several decades ago.

In a study of 20,000 Mexicans age 20 and older, researchers found that smoking and obesity were the most prevalent heart disease risk factors. One-third of men said they smoked, while half of women were found to have abdominal obesity (defined as having a waist size of about 35 inches for women, 40 inches for men).

High blood pressure was not far behind -- affecting almost 30 percent of both men and women. Meanwhile, about 13 percent of adults had diabetes, and a similar percentage had high cholesterol.

Those figures are a far cry from the Mexico of 50 years ago, the researchers point out in the American Heart Journal.

In 1960, the nation's rate of diabetes was less than 3 percent, before rising to 8 percent during the 1980s. Similarly, high blood pressure rose from a rate of about 10 percent, to 20 percent in the 1990s, to where it stands now.

Those patterns mirror the trend past studies have shown in Mexico's rate of death from heart disease, which nearly doubled between 1970 and 2000. The current rate -- about 56 heart disease deaths per 100,000 people -- is still lower than that of the U.S., where the rate in 2006 was 135 per 100,000.

That gap, however, is somewhat misleading, as the U.S. population is older than Mexico's. Moreover, the two nations' heart disease trends are going in opposite directions.

Between 1970 and 2000, the U.S. and Canada showed a roughly 63 percent drop in their rates of deaths from heart disease, noted Dr. Jorge Escobedo, one of the researchers on the new study.

It's believed, he told Reuters Health in an email, that this reduction resulted both from improved treatments for heart disease and from a decline in the number of people developing heart disease.

A number of factors likely help explain the trend seen in Mexico, according to Escobedo, who is with the Mexican Social Security Institute, which provides health care to 45 percent of the Mexican population. (The nation's healthcare system involves a mix of public and private services.)

For one, the country is showing a pattern common to nations undergoing industrialization: Over the second half of the last century, fewer and fewer Mexicans were dying early of infectious disease; that meant that more and more were living long enough to develop major risk factors for heart disease, like type 2 diabetes, and of course heart disease itself.

In 1950, Escobedo pointed out, life expectancy in Mexico was only 47 years. Today it's estimated to be 75 years.

However, Escobedo said, changes in lifestyle -- less physical activity and a move away from traditional diets -- are also likely involved.

Smoking has become a substantial problem in Mexico, especially among men. And the younger population has the highest rates: Escobedo's team found that among men in their 20s, 38.5 percent said they smoked; that compared with 20 percent of men in their 60s.

According to the researchers, Mexico appears to be in between what are considered the second and third stages of the tobacco epidemic. The second stage is marked by an increase in a population's number of female smokers, plus a 50 percent or greater increase in the number of male smokers. In the third stage, those rates plateau and a slow dip begins in the rate of smoking among men.

So Mexico's smoking rates have yet to plateau.

According to Escobedo, public health efforts to prevent smoking, obesity and other heart risk factors among younger Mexicans are needed.

The battle against smoking should be reinforced, he said. Actions to reduce obesity should be implemented.

Moreover, Escobedo said, people who already have conditions like diabetes and high blood pressure need to get them under better control to lower their chances of developing heart disease.

Part of the problem in Mexico, he noted, is that many people, and even some health providers, are not aware of the importance of managing disorders like diabetes.

Access to treatment is another obstacle; Mexico's patchwork of public and private insurance programs has meant unequal access to better-quality healthcare.

According to Escobedo, about 11 percent of the population remains uninsured, while 29 percent receive government-run care through a program called popular health insurance -- which, Escobedo said, provides quite limited services.


American Heart Journal, August 2010.