Effects Of Age And Conditioning Status On Rest And Exerc

年龄和体能状况对休息和锻炼的影响

• 批准号: 7132338
• 负责人: Samer Najjar
• 金额: --
• 依托单位: NATIONAL INSTITUTE ON AGING
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/7132338
• 关键词: aerobic exercise; age difference; aging; cardiac output; clinical research; exercise; gender difference; heart function; human middle age (35-64); human old age (65+); human subject; lifestyle; longitudinal human study; oxygen consumption; physical fitness; rest; young adult human (21-34)

Summary:Our laboratory utilizes multiple techniques to determine the effects of age, gender and lifestyle habits on cardiovascular (CV) performance at rest and during exercise. (A) We examined whether age affects midwall systolic left ventricular (LV) performance, a more sensitive marker for determining myocardial dysfunction than standard endocardial measures. In 330 normal BLSA men (n=141) and women (n=189), those older than the median age of 50 years had smaller LV cavities, greater wall thickness, and higher endocardial fractional shortening than younger subjects. However, midwall shortening was not significantly age-related in either sex. Furthermore, the relationship between midwall shortening and end-systolic stress was similar in older versus younger groups. Thus, normative aging appears to have minimal effect on LV systolic performance whether measured at the LV endocardium or the midwall. (B) Longitudinal changes of maximal aerobic capacity (VO2max) were determined in nearly 1,400 Baltimore Longitudinal Study of Aging (BLSA) volunteers without evident cardiac disease, using mixed effects statistical analysis. Per decade, longitudinal declines in VO2max were generally greater than cross-sectional declines, especially in older decades. Gender differences in both absolute VO2max and rates of decline (men>women) are markedly attenuated when VO2max was normalized for fat-free mass rather than body weight (Circulation. 2005;112(5):674-82). (C) The longitudinal decline in VO2max was determined in 42 older male endurance athletes, initially 64 (plus or minus) 6 years old. Over a mean follow-up of 7.8 years, VO2max declined by 22%, triple the decrease predicted by the baseline cross-sectional data. Within the overall sample, training status during follow-up had a major effect on the change in VO2max: the 6 men who continued to train vigorously had no significant decline in VO2max (0.28%/yr.), the 20 that trained at a lower intensity declined by 2.6% / yr, and the 14 who stopped training declined 4.6% / yr. Thus, physical activity patterns have a major impact on the long-term changes in maximal aerobic capacity in older athletes. (D) Left ventricular thickness, mass and chamber dimensions were measured in 336 healthy, normotensive adults (mean age 56+/-18 years, 200 women, 136 men) by magnetic resonance imaging (MRI). We found that the left ventricle becomes more spherical with age in normal adults because of reduced length. In women, this is associated with an increased wall thickness which offsets the decrease in length, resulting in left ventricular mass not changing with age. In men, wall thickness does not compensate for the increased sphericity, resulting in decreased left ventricular mass with age (Am J Cardiol 2002;90:1231-1236). (E) Ejection fraction (EF) acutely increases during exercise, but the EF reserve decreases with advancing age. EF is inversely related to the index of the interaction between arterial and ventricular properties, defined by the ratio of arterial elastance (EaI) to left ventricular systolic elastance (ELVI). We noninvasively characterized the arterial-ventricular coupling index EaI/ELVI and its two determinants at rest and during graded exercise in 136 healthy men and 103 healthy women (age range 21-87 years) from the Baltimore Longitudinal Study of Aging. We found that age-associated differences in EaI/ELVI occur in both genders during exercise, with less optimal coupling in older compared to younger subjects, which may help to explain the age deficit in maximal exercise EF. We also found that the mechanisms underlying the sub-optimal coupling in older adults differed between men and women (J Am Coll Cardiol. 2004;44(3):611-617). (F)Diastolic heart failure is common in older women, often occurs following longstanding hypertension, and is characterized by reduced cardiovascular reserve during exercise. Recent insights suggest that arterial-ventricular coupling (AV-C), which is an important determinant of cardiovascular performance, may play an important role in the pathophysiology of diastolic heart failure. AV-C was measured at rest and with graded cycle ergometry in 142 normotensive and 35 hypertensive women free from overt cardiovascular disease. AV-C was 26% lower in hypertensive than normotensive women at rest. The AV-C reserve, calculated as the difference in AV-C between rest and peak exercise was also smaller in the hypertensive than normotensive women (0.2plus or minus 0.03 vs 0.28 plus or minus 0.01, p<0.001). Thus, examination of AV-C at rest and with exercise provides mechanistic insights into why hypertension may predispose older women to diastolic heart failure. (G) Although it is well established that evidence of coronary ischemia during treadmill exercise is associated with an increased likelihood of future coronary events (angina pectoris, myocardial infarction or death), even in clinically healthy populations, less is known about the prognostic significance of the absence of objective evidence of ischemia, as determined from electrocardiography (ECG), tomographic thallium scintigraphy, or both. We performed maximal treadmill exercise ECG and thallium scintigraphy (201Tl) in 697 asymptomatic volunteers (57% men) with no clinical history of coronary heart disease from the Baltimore Longitudinal Study of Aging. The average age was 62 plus or minus 12 years. 289 subjects had evidence of ischemia on the stress test: 193 had a positive ECG, and 175 a positive Tl201. Over a mean follow-up period of 6.7 years, cardiac events developed in 11% of subjects. Events occurred in 10% of individuals with a negative ECG, 8% of those with a negative 201Tl, and 7% of those with concordant negative 201Tl and ECG. After adjusting for age and other covariates, negative ECG was not associated (p=NS), whereas a negative 201Tl was weakly associated (hazard ratio=0.62, 95%CI 0.37-1.04, p=0.07) with the absence of future events. Concordant negative ECG and 201Tl was an independent predictor of freedom from events (hazard ratio=0.58, 95% CI 0.34-0.97, p=0.03), with a sensitivity, specificity and negative predictive value of 62%, 61% and 93% respectively. Thus, in healthy individuals, the concordant absence of ischemia on both ECG and 201Tl provides independent prognostic information.

摘要：我们的实验室利用多种技术来确定年龄，性别和生活方式习惯对静止和运动过程中心血管（CV）表现的影响。 （a）我们检查了年龄是否影响Midwall收缩性左心室（LV）性能，这是确定心肌功能障碍的更敏感的标记，而不是标准心内膜心脏措施。在330名正常BLSA男性（n = 141）和女性（n = 189）中，比中位年龄的年龄年龄较小的LV腔较小，壁厚较大，并且患有更高的心内膜小部分缩短。但是，在这种性别中，米斯壁缩短均未显着与年龄相关。此外，在较老的群体中，中间缩短缩短与终端施加压力之间的关系相似。因此，无论是在LV心内膜外测量还是Midwall测量，规范性衰老似乎对LV收缩性能具有最小的影响。 （b）使用混合效应统计分析，在不存在明显心脏病的情况下，在近1400个巴尔的摩纵向研究（BLSA）志愿者的近1,400次巴尔的摩纵向研究中确定了最大有氧能力（VO2MAX）的纵向变化。每十年，VO2MAX的纵向下降通常大于横截面下降，尤其是在年龄较大的几十年中。当Vo2max的无脂肪质量而不是体重化时，绝对VO2MAX和下降率（男性>女性）的性别差异显着减弱（循环。2005; 112（5）：674-82）。 （c）在42名年长的男性耐力运动员中确定了VO2MAX的纵向下降，最初64岁（加上或负）6岁。在平均随访7。8年的时间里，VO2MAX下降了22％，三倍的下降是基线横截面数据预测的下降。在整个样本中，随访期间的训练状况对VO2MAX的变化产生了重大影响：继续大力训练的6名男子的VO2MAX没有显着下降（0.28％ /年），这20人以较低的强度下降了2.6％ /年，而停止训练的14人则下降了4.6％ /年。因此，体育活动模式对老年运动员最大有氧能力的长期变化产生了重大影响。 （d）通过磁共振成像（MRI）测量了336位健康的，正常的成年人（平均年龄56 +/- 18岁，男性，136名男性），测量了左心室厚度，质量和腔室尺寸。我们发现，由于长度降低，左心室随着正常成年人的年龄而变得更加球形。在女性中，这与壁厚的增加有关，该壁厚会抵消长度的减小，从而导致左心室质量不会随着年龄的增长而变化。在男性中，壁厚不能补偿球形的增加，导致左心室随着年龄的增长而减少（AM J Cardiol 2002; 90：1231-1236）。 （e）弹出分数（EF）在运动过程中急剧增加，但EF储备随着年龄的增长而减少。 EF与动脉和心室特性之间相互作用的指数成反比，该指标由动脉弹性（EAI）与左心收缩压弹性（ELVI）的比率定义。我们非侵入性地表征了动脉 - 室里耦合指数EAI/ELVI及其在休息时的两个决定因素，并在136名健康男性和103位健康女性（21-87岁）中进行了分级运动，来自巴尔的摩的衰老纵向研究。我们发现，与年轻受试者相比，在运动过程中，EAI/ELVI与年龄相关的EAI/ELVI差异都发生在老年人中的最佳耦合，这可能有助于解释最大运动EF的年龄不足。我们还发现，男性和女性的老年人中次优耦合的基础机制不同（J Am CollCardiol。2004; 44（3）：611-617）。 （f）舒张性心力衰竭在老年女性中很常见，通常发生在长期高血压之后，其特征是运动过程中心血管储备降低。最近的见解表明，动脉 - 室性耦合（AV-C）是心血管表现的重要决定因素，可能在舒张性心力衰竭的病理生理学中起重要作用。 AV-C在休息时进行测量，并在142名正常血统和35名高血压女性中使用分级周期测量值，没有明显的心血管疾病。高血压的AV-C比静止妇女低26％。在高血压中，AV-C储备计算为AV-C之间的AV-C差异也小于正常性女性（0.2plus或减去0.03 vs 0.03 vs 0.28 + 0.28 Plus或负0.01，p <0.001）。因此，在休息和运动中对AV-C的检查提供了机械洞察力，说明为什么高血压会使老年妇女患舒张性心力衰竭。 （g）尽管已经良好确定在跑步运动过程中冠状动脉缺血的证据与未来的冠状动脉事件（心绞痛，心肌梗死或死亡）的可能性增加有关，即使在临床健康的人群中，对于缺乏局限性的预后证据，cogs throscraphy（ecg）的预后证据也不太了解。我们在697名无症状志愿者（57％的男性）中进行了最大的跑步机ECG和Thallium闪烁显像（201TL），而巴尔的摩衰老纵向研究没有冠心病的临床史。平均年龄为62岁或减去12岁。 289名受试者在压力测试中有缺血的证据：193的心电图正阳性，而175个阳性TL201。在平均6。7年的随访期内，心脏事件发生在11％的受试者中。事件发生在10％的ECG阴性的个体中发生，其中8％的201TL和7％的人患有共和度为201TL和ECG的人中有7％。调整了年龄和其他协变量后，阴性心电图无关（p = ns），而阴性201TL弱相关（危险比= 0.62，95％CI 0.37-1.04，p = 0.07）与没有未来事件的情况下相关。一致的负ECG和201TL是对事件自由的独立预测指标（危险比= 0.58，95％CI 0.34-0.97，p = 0.03），其灵敏度，特异性和阴性预测值分别为62％，61％和93％。因此，在健康的个体中，ECG和201TL缺血的一致性提供了独立的预后信息。