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BOSTON, MASSACHUSETTS. It is well-established that both a high systolic blood pressure (the highest of
the two blood pressure readings) and a high diastolic pressure are closely associated with increased
cardiovascular and total mortality in middle-aged people. The correlation between blood pressure and
mortality in older people (aged 65 years or over) is, however, much less clear. Some researchers have
found that there is a U-shaped relationship between blood pressure and mortality in older people. Researchers at the Harvard Medical School have just released a major study aimed at clarifying the correlation. The study involved 9431 participants, aged 65 to 102 years, who were enrolled in 1981 and had their blood pressure measured at that time (average of three readings). After 10 years of follow-up, 4528 of the participants had died, 2304 from cardiovascular disease.
The results of the study showed that people with a systolic pressure less than 130 mm Hg and diastolic
pressure between 80 and 89 mm Hg had the best survival rate. The worst survival rate occurred among
people with a systolic pressure above 160 mm Hg and a diastolic pressure less than 70 mm Hg. The death
rate in this latter group was 90 per cent higher than in the former group. The researchers conclude that
pulse pressure (systolic pressure minus diastolic pressure) is the best predictor of mortality in older people.
A pulse pressure less than 53 mm Hg is optimum with a pulse pressure above 77 mm Hg corresponding to
an increased overall mortality of 34 per cent and an increased cardiovascular mortality of 57 per cent. The
researchers emphasize that pulse pressure is not a consistent predictor of cardiovascular disease in middle-
aged people. NOTE: This study was partially funded by Bristol-Myers Squibb, a pharmaceutical
company.
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