The Relationship Between 24-hour Ambulatory Diastolic Blood Pressure, Pulse Pressure And Cardiovascular Risk In Eldely Men

Objective The goal of this study was to investigate the relationship between ambulatory diastolic blood pressure levels and cardiovascular risk in the elderly men with treated essential hypertension. Methods The study population consisted of 1034 men(748 hypertensives;286 normotensives) aged 60 years and older who had undergone 24-hour ambulatory blood pressure monitoring since May 1995 until September 2001. All of the hypertensives had been under antihypertensive drug therapy and the first cardiovascular disease events(CVE) events )were recorded during the follow-up. Results A total of 174 first CVD events were recorded during a 2.3 ?.3-year follow-up period. When data were analyzed on the whole individuals, the highest CVD events rates (12.3/100 patient-year) were observed in those with the highest ambulatory diastolic blood pressure levels (^85 mm Hg), whereas the lowest CVD events rates (6.1/100 patient-year) were recorded in the group with ambulatory diastolic blood pressure 65 to 74 mm Hg(P<0.01); the CVD events rates(9.1/100 patient-year) of the lowest ambulatory diastolic blood pressure levels (<65 mm Hg) were higher than those of the group with ambulatory diastolic blood pressure 65 to 74 mmHg(/)<0.05),However,after adjustment for the other risk factors including age, smoking history , hypertension history, diabetes, previous cardiovascular disease,total cholesterol and left ventricular mass index, the difference of the CVD events rates between the two groups was disappear. In the treated hypertensives, aindependently U-shaped curve relationship between the CVD events rates and the.. 3 ~ambulatory diastolic blood pressure was observed. The highest CVD events rates were recorded in those with the lowest ambulatory diastolic blood pressure levels (<70 mm Hg) (11.9/100 patient-year) and in those with the highest ambulatory diastolic blood pressure levels (^90 mm Hg) (13.6/100 patient-year). The lowest CVD events rates were recorded in the group with ambulatory diastolic blood pressure 70 to 79 mm Hg(7.0/100 patient-year). Compared with this group, the CVD events rates was increased about 1.7 times (P < 0.02) in the lowest ambulatory diastolic blood pressure group (<70 mm Hg) and about 2.0 times (P < 0.01) in the highest ambulatory diastolic blood pressure group (^90 mm Hg) even after adjustment for the other risk factors including age, smoking history, use of antihypertensive drug, diabetes, previous cardiovascular disease,total cholesterol and left ventricular mass index. In the normotensives, different ambulatory diastolic blood pressure levels did not influence the CVD events rates significantly. Conclusion We demonstrated that low ambulatory diastolic blood pressure was associated independently with increased CVD events rates in the elderly men with essential hypertension. This may indicate that the therapeutic goal of "the lower the better" is not the optimal strategy in the elderly men. Our data do lend support to speculations that there is overtreatment of some specific hypertension, which would increase cardiovascular risk through making diastolic blood pressures too low. Further studies need to determine whether excessively low diastolic blood pressures can be prevented by more careful antihypertensive therapy while maintaining systolic blood pressures control.