High blood pressure, although it often causes no symptoms by itself, is a main risk factor for heart attack and stroke, two of the leading causes of death in the United States. Efforts to diagnose and treat high blood pressure showed considerable success during the years 1976 to 1991. During this time, awareness of high blood pressure increased from roughly 50% to 75% of cases, treatment of the condition increased from 30% to over 50% of cases, and the number of cases with suitable control of the blood pressure increased from 10% to 30%. Unfortunately, these measures of success leveled off, or even declined slightly, in the next few years. A new study of residents of Minnesota suggests that the situation has deteriorated still further.

People over 45 living in Olmsted County, Minnesota, were invited to participate in this study. They were examined at home and then at the Mayo Clinic, Rochester, where they had heart tests (echocardiography) and their medical records were reviewed. At the home visit a series of blood pressure measurements were made, and the subjects were asked two questions:

• Has a doctor ever told you that you had high blood pressure or hypertension?
• Are you currently taking any medications for blood pressure?

If their upper blood pressure reading (the systolic blood pressure - SBP) was above 140 or their lower blood pressure (the diastolic blood pressure - DBP) was over 90 they were diagnosed as having uncontrolled high blood pressure. If the blood pressure was less than 140/90 in people answering yes to question 1, they were defined as having controlled high blood pressure. People were classified as "aware" if they answered yes to question 1, and "unaware" if they answered no to question 1 and had high blood pressure.

Over 630 subjects were recruited, but about one-third were not eligible because of illnesses interfering with their evaluation. The average blood pressures were 138/80 for men and 137/76 for women, with slight increases in mean SBP and decreases in mean DBP with age. The actual frequency of high blood pressure from the readings made at home and at the clinic was 41%. However, when the subjects who had high blood pressure according to their answer to question 1 were included, the frequency increased to 53%.

Analyzing the 370 people with high blood pressure provided the important findings of this study. Of these subjects, over 16% were aware of their condition, were having treatment for it and had a well-controlled pressure (i.e. below 140/90). 28% of those with high blood pressure were aware of this and were receiving treatment, but blood pressure control was inadequate (i.e. it was above 140/90). Most alarmingly, over 38% were unaware that they had high blood pressure at all. To make matters worse, roughly 15% of those considered to have high blood pressure (i.e. those with measured high levels or answering yes to Question 1) were not being treated.

These results show a deterioration of the findings of the survey made in 1993, and present what the authors of the study call a "disturbing" picture. With this situation in a relatively prosperous community in the United States with good access to medical services, one must question how things may be in other parts of the world? Clearly, there is a need for continued high-level awareness, both by patients and physicians, of the risks of high blood pressure, and the need for recognition and treatment of the condition before complications ensue. This is important not only for people in the United States, but in all countries where high blood pressure is a serious trigger for heart attack and stroke.

Source

Detection and Control of High Blood Pressure in the Community: Do We Need a Wake-Up Call?
I. Meissner, JP. Whisnant, SG. Sheps, Hypertension, 1999, vol. 34, pp. 466--47