Piccirillo G, Cacciafesta M, Viola E, Santagada E, Nocco M, Lionetti M, Bucca C, Moisè A, Tarantini S, Marigliano V
Isituto di Prima Clinica Medica, Università La Sapienza, Roma, Italy.
Clin Sci (Lond). 2001 Mar;100(3):267-74.
Aging reduces cardiac baroreflex sensitivity. Our primary aim in the present study was to assess the effects of aging on cardiac baroreflex sensitivity, as determined by power spectral analysis (alpha index), in a large population of healthy subjects. We also compared the alpha indexes determined by power spectral analysis with cardiac baroreflex sensitivity measured by the phenylephrine method (BS(phen)). We studied 142 subjects (79 males/63 females; age range 9-94 years), who were subdivided into five groups according to percentiles of age (25, 50, 75 and 95). Power spectral analysis yields three alpha indexes: an alpha low-frequency (LF) index of cardiac baroreflex sensitivity that ranges around 0.1 Hz; an alpha high-frequency (HF) index reflecting cardiac baroreflex sensitivity corresponding to the respiratory rate; and alpha total frequency (alpha TF), a new index whose spectral window includes all power in the range 0.03-0.42 Hz. Spectra were recorded during controlled and uncontrolled respiration. Under both conditions, all three alpha indexes were higher in the youngest age group (< or =34 years old) than in the three oldest groups. Notably, alpha TF was significantly higher in younger subjects than in the three oldest groups [14+/-1 ms/mmHg compared with 9+/-1 (P<0.05), 8.1+/-1 (P<0.001) and 8.1+/-1 (P<0.05) ms/mmHg respectively]. BS(phen) showed a similar pattern [12+/-1 ms/mmHg compared with 8+/-0.5 (P<0.001), 6+/-0.5 (P<0.05) and 6+/-1 (P<0.05) ms/mmHg respectively]. No significant differences were found for cardiac baroreflex sensitivity among the three oldest groups. All alpha indexes were correlated inversely with age. The index yielding the closest correlation with BS(phen) was alpha TF (r=0.81, P<0.001). Cardiac baroreflex sensitivity in normotensive individuals declines with age. It falls predominantly in middle age (from approx. 48 years onwards) and remains substantially unchanged thereafter. The elderly subjects we selected for this study probably had greater resistance to cardiovascular disease that is manifested clinically, with preserved cardiac baroreceptor sensitivity.
衰老会降低心脏压力反射敏感性。本研究的主要目的是在大量健康受试者中，评估衰老对通过功率谱分析（α指数）测定的心脏压力反射敏感性的影响。我们还将通过功率谱分析测定的α指数与用去氧肾上腺素法（BS(phen)）测量的心脏压力反射敏感性进行了比较。我们研究了142名受试者（79名男性/63名女性；年龄范围9 - 94岁），根据年龄百分位数（25、50、75和95）将他们分为五组。功率谱分析产生三个α指数：一个反映心脏压力反射敏感性的低频（LF）α指数，频率范围约为0.1赫兹；一个反映与呼吸频率相对应的心脏压力反射敏感性的高频（HF）α指数；以及α总频率（αTF），这是一个新指数，其频谱窗口包括0.03 - 0.42赫兹范围内的所有功率。在有控制的呼吸和无控制的呼吸过程中记录频谱。在这两种情况下，所有三个α指数在最年轻的年龄组（≤34岁）中都高于最年长的三个年龄组。值得注意的是，年轻受试者的αTF显著高于最年长的三个年龄组[分别为14±1毫秒/毫米汞柱，与之相比，最年长三个年龄组分别为9±1（P<0.05）、8.1±1（P<0.001）和8.1±1（P<0.05）毫秒/毫米汞柱]。BS(phen)显示出类似的模式[分别为12±1毫秒/毫米汞柱，与之相比，最年长三个年龄组分别为8±0.5（P<0.001）、6±0.5（P<0.05）和6±1（P<0.05）毫秒/毫米汞柱]。在最年长的三个年龄组之间未发现心脏压力反射敏感性有显著差异。所有α指数均与年龄呈负相关。与BS(phen)相关性最密切的指数是αTF（r = 0.81，P<0.001）。血压正常个体的心脏压力反射敏感性随年龄下降。主要在中年（约48岁以后）下降，此后基本保持不变。我们为这项研究选择的老年受试者可能对临床上表现出的心血管疾病具有更大的抵抗力，且心脏压力感受器敏感性得以保留。
