Study - Top blood pressure number is better risk predictor

CHICAGO -- A study of 4,714 French men bolsters evidence that the top number in blood pressure readings is better than the lower number at predicting heart disease risk, even in middle-aged patients.

For years doctors thought it was more important to try to lower the bottom, diastolic reading to reduce the health risks of high blood pressure, including heart disease, stroke and kidney failure.

While many doctors still focus on diastolic readings, more recent research has suggested that the top, or systolic, measure, is more important, especially in the elderly. The new study extends those findings to men aged 52 on average.

The results are published in today's Archives of Internal Medicine.

The systolic reading represents pressure when the heart beats; the diastolic shows pressure in between beats when the heart relaxes. Optimal blood pressure is 120 over 80 or lower.

High blood pressure -- 140 over 90 or higher -- affects more than 50 million U.S. adults.

In the French study, men with systolic readings of 160 or higher faced more than double the risk of dying from cardiovascular disease during an average follow-up of 14 years, compared with men whose systolic numbers were under 140. Those with systolic numbers between 140 and 160 faced a lower but still increased risk.

There was no increased cardiovascular risk for men with elevated diastolic numbers.