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"There is a doubling of cardiovascular risks that begins at this point," says Dr. George Bakris of Rush University Medical Center in Chicago. That means up to 45 million people who thought they were on safe ground may be at risk.
To try to make this point as emphatically as possible, the NHLBI labels the borderline pressure range "prehypertension," a mildly alarming term that was chosen for precisely that reason. "We convened focus groups; presented them terms such as high normal, borderline and abnormal vascular response; and asked them which would get across the idea that they had to take action," says Bakris. "Ninety-eight percent said prehypertension would do it."
If the nation's hypertension problem is going to be controlled, epidemiologists know that one place they're going to have to start is in the Latino and black communities. Mexican Americans have a hypertension incidence 5.5% higher than that of whites, and African Americans a whopping 43% higher. Epidemiologists have advanced any number of explanations for the hypertension problem in the black population. One of the most intriguing--if least provable--has been that the brutal conditions aboard slave ships crossing the Atlantic served as a sort of adaptive choke point, selecting for people with a tendency to retain salt and water. This allowed them to survive the murderous journey without succumbing to thirst but predisposed their descendants to hypertension. Dr. Lawrence Appel of the Johns Hopkins University School of Med-icine believes that modern-day African Americans do process sodium a bit differently from whites and may even have a less reactive renin-angiotensin system.
But while many researchers concede that genes may play such a role, they believe cultural variables are far more important. "African Americans generally have lower economic well-being and the ability to make lifestyle changes and purchase medicines," says the CDC's Labarthe. Indeed, a 10-country, 85,000-person study revealed that, worldwide, it is whites who are as much as twice as likely to suffer from hypertension, with countries like Poland and Finland--where diets are high in fat and low in fruits and vegetables--leading the way. In a socioeconomic environment in which African Americans are often forced to eat cheap, unhealthy food (the National Institutes of Health is worried particularly about cured meats, pickled foods, canned fish, salty snacks and sauces), it's no wonder their blood pressure is high.
Pregnant women are another high-risk group, whether they had hypertension going into the pregnancy or not. High pressure during pregnancy--160/110 or above--can lead to maternal seizures and even death. It can also cause premature births or stillbirths.