正常人动态动脉僵硬指数随年龄的变化及与24 h脉压的相关性

目的 动态动脉僵硬指数(AASI)是新近提出的反映收缩压(SBP)和舒张压(DBP)之间动力学关系的一项指标,这项研究的主要目的是探讨正常人AASI随年龄的变化及其与24 h脉压(24 h PP)的相关性.方法 246名正常人平均年龄(59.7±14.6)岁,女性占38.6%]在保持日常工作和生活起居的情况下配戴24 h动态血压监测(ABPM)仪,记录从早晨6:00到晚上22:00每间隔30min和从晚上22:00到第2天早晨6:00每问隔60 min的血压读数、心率(HR)、平均动脉压(MAP)及脉压(PP),然后按AASI=1-DBP对SBP的回归斜率计算每个个体的AASI值.结果 AASI随年龄的增大而增大.在正常人中,AASI的第95百分位数是0.56,其95%预测区间的上界在20～39岁时为0.49,40～59岁时为0.59,60～79岁时为0.69,≥80岁时为0.79.AASI与24 h PP呈正相关(r=0.497,P＜0.01).在正常人中,AASI随年龄的增长呈直线增加,而24 h PP随年龄增长呈曲线增加.结论 AASI作为反映血压关系的指标,其在正常人中表现为随年龄增大而增大的变化规律;与传统指标24 h PP相关,提示可作为预测动脉僵硬程度的新指标.

Change in ambulatory arterial stiffness index with advancing age and the correlation with 24 hours pulse pressure in healthy individuals

Objective Ambulatory arterial stiffness index (AASI) has been recently proposed to reflect the dynamic relation between diastolic and systolic blood pressure throughout the whole day. The aim of our study was to investigate the change in AASI with advancing age and the correlation with 24 hours pulse pressure (24 h PP) in healthy individuals. Methods 246 healthy subjects mean age(59. 7 ±14.6) years, women 38.6% ] underwent 24 hours ambulatory blood pressure monitoring ( ABPM) in normal life style. The blood pressure recordings, heart rate (HR) , mean arterial pressure (MAP) and pulse pressure (PP) were analyzed simultaneously by computer for every 30 minutes during 6:00 am-22:00 pm and every 60 minutes during 22:00 ptn-6:00 am. Using all the blood pressure recordings, we plotted diastolic against systolic blood pressure from each individuals and calculated the regression slope. AASI was derived from 1 minus this regression slope. Results In 246 healthy individuals, AASI increased with age. Among the healthy individuals, the 95th percentile of AASI was 0. 56, the upper boundary of the 95% prediction interval of AASI in relation to age were 0.49 at 20 - 39 years ,0.59 at 40 - 59 years ,0.69 at 60 - 79 years, 0.79 at≥80 years. The correlation coefficient between AASI and 24 h PP was 0.497(P <0. 01 ). AASI linearly increased with age in healthy individuals, whereas the relation between pulse pressure and age was curvilinear. Conclusions AASI as a index reflecting blood pressure relationship, manifested the corresponding change with advancing age. The correlation between AASI and traditional index 24 h PP indicated AASI as a new measure of arterial stiffness.