A new study by researchers at the University of Texas Medical Branch at Galveston reveals that the prevalence of hypertension in older Mexican-Americans living in the Southwest region of the United States has increased slightly in the last decade.

Researchers suspect the rise is due, in part, to the increase in diabetes and obesity.

Although hypertension, or high blood pressure, is one of the most common diseases in the United States, affecting more than 72 million Americans, it is one of the most manageable risk factors for cardiovascular disease.

Advancements in the diagnosis, treatment and control of hypertension have been major contributors to the decline in cardiovascular mortality in recent decades.

"We always expect that things are improving, right?" said Kyriakos S. Markides, co-author and principal investigator of the study, which has been funded by the National Institute on Aging since 1992. "But now we're finding that, in the more recent study participants, they're more disabled, have more diabetes, have slightly more obesity and slightly more hypertension."

The study, which appears in the January issue of the Annals of Epidemiology, looked at 3,952 older Mexican-Americans residing in Texas, New Mexico, Colorado, Arizona and California. A group of 3,050 men and women, 65 and older, were evaluated in 1993-1994, and an additional 902 men and women, 75 and older, were added in 2004-2005. Researchers interviewed the study subjects and took health measurements every two to three years.

The hypertension prevalence rates were significantly different in 1993-1994 compared with 2004-2005 (73 percent vs. 78.4 percent, respectively). The increase in hypertension prevalence was significant for subjects 75 to 79 years, for U.S.-born subjects, for subjects with diabetes and for the obese.

Self-reported hypertension was assessed by asking subjects if a doctor had ever told them that they had high blood pressure. Blood pressure readings were taken by interviewers during in-home visits. Participants were asked to provide the containers of the medications taken in the two weeks prior to the interview, and drug names were recorded.

Subjects were considered hypertensive if they had been told by a physician that they had hypertension, if they had an average systolic blood pressure of 140 mm Hg or higher or an average diastolic blood pressure of 90 mm Hg or higher, or if they were taking antihypertensive medications.

While overall hypertension awareness was significantly higher in 2004-2005 than in 1993-1994 (82.6 percent vs. 63 percent, respectively), diabetic and obese subjects were more likely to be hypertensive in 2004-2005 than in 1993-1994.

There's good news and bad news, said Markides. "The bad news is the prevalence of hypertension went up — not a huge increase, but up nonetheless — due in part to obesity and diabetes. The good news is that the hypertension is better controlled because of increased awareness and better management."

Hispanics living in the United States are expected to number 120 million by 2050. "This is a long-living population with increasing rates of disability, diabetes and chronic disease," said Markides.

"More effort should be targeted to reverse trends of both obesity and diabetes as potential causes of increases in hypertension," wrote Markides and his collaborators. "Further investigations should be directed toward providing clear guidelines and goals for hypertension treatment and control in the very old to improve hypertension outcomes in this population."