The survey found the rate of diabetes was 15.7 percent among adults, which is more than 3 percent higher than previous studies, said Dr. Joxel Garcia, deputy director of the Pan American Health Organization.

"We had some perceptions about the prevalence of diabetes and now we know the reality of what is happening on the border," he said in a telephone interview from a meeting of health professionals in El Paso, Texas.

This is higher than the comparable 13.9-percent rate of diabetes in the United States and 14.9-percent rate in Mexico, the report said.

The significance of the new finding is that it means there are from 240,000 to 250,000 more people with diabetes in the region than earlier believed. More than 8 million people reside along both sides of the 2,000-mile border that was surveyed.

"That tells us that you have a higher risk for heart disease, blindness, amputation, renal failure, strokes and other diseases associated with diabetes," Garcia said.

The study also found the rate of obese and overweight adults along the border is more than 75 percent, compared to a rate of 62 percent in the United States.

"That by itself is a significant risk for a population," he said.

Although genetic factors are involved in diabetes, obesity contributes to the disease. More than three-quarters of those surveyed on each side of the border were overweight.

The study is the first of its kind to study the prevalence of diabetes in a border region anywhere in the world, said Garcia, whose agency is an arm of the World Health Organization. The U.S.-Mexico study will be a model for future research in other regions around the globe.

Other agencies involved in the survey of 10 states on both sides of the border between Texas and California included the U.S. Centers for Disease Control and Prevention, the Mexico Secretariat of Health, the PAHO and others.

The researchers interviewed people in the Mexican states of Baja California, Sonora, Chihuahua, Nuevo Leon, Coahuila and Tamaulipas. In the United States, they surveyed residents selected at random in Texas, New Mexico, Arizona and California.

More than 4,000 people were questioned for the study, the most exhaustive survey conducted along the border. Researchers collected blood samples and height and weight measures from each person. Nearly 3,000 of the subjects were women and they ranged in age from 18 to over 60.

The sample was almost evenly divided from each side of the U.S.-Mexico border, and about 88 percent of those surveyed were Hispanic. Diabetes is found more frequently among that demographic group, according to health experts.

Garcia said diabetes and obesity are becoming more prevalent among the U.S. Hispanic population, so this was "magnified" in the border study.

About 8.2 percent of all Hispanic/Latino Americans aged 20 years or older have diabetes, according to the American Diabetes Association. On the average, they are 1.5 times more likely to have diabetes than non-Hispanic whites of similar age.

Mexican Americans, the largest Hispanic subgroup, are more than twice as likely to have diabetes than non-Hispanic whites of similar age, the association said. Residents of Puerto Rico are 1.8 times more likely to have diagnosed diabetes.

The purpose of the study was to gather accurate data on the prevalence of the disease to aid local, state and federal health officials trying to prevent its growth.

The report will be distributed to health agencies on both sides of the border, and the finding of an increased diabetes rate may lead to changes in programs, Garcia said.

"The reality here is very different from the reality in both countries," he said. "That means whatever we are doing in Mexico and the United States may or may not apply to what is happening here in the border."

Garcia said health organizations would work to identify the resources that can be utilized to reduce the prevalence of diabetes and increase public awareness. He said education is a big part of the mission in fighting diabetes.

"Forty percent of the people with diabetes don't know they have diabetes, which is significant, and the average person on the border is already overweight," Garcia said.

Many in the El Paso-Juarez, Mexico, area are concerned about diabetes, the El Paso Times reported.

"It's pretty painful to see this happen to people, especially to little kids and family members," said Henry Flores, whose parents, wife and son have diabetes.

"It affects everyone in the family. It is pretty scary. You know, as a father I feel defenseless.