Bojić M, Djurić D, Petrović J, Popović Z, Tasić N, Petrović B, Djurić A, Bojić D, Plećas B, Mitrović V, Kanjuh V
Laboratory of Atherosclerosis and Vascular Biology Research, Dedinje Cardiovascular Institute, Belgrade.
Srp Arh Celok Lek. 1999 Mar-Apr;127(3-4):101-8.
Aging is correlated with decreased endothelial vasomotor influence, increased carotid intima-media thickness and stiffness, increased left ventricular mass index and increased blood pressure [1-3]. However, these changes are not expressed in the same way in both genders [4, 5]. It seems that females are more protected from cardiovascular changes during aging compared to males [1, 6].
The aim of the study was to evaluate the influence of gender on brachial vasomotor responses (reactive hyperemia test) as well as the correlation with vascular and cardiac remodelling in healthy volunteers of different ages.
The study was carried out on healthy subjects (n = 66; 37 males, 29 females) of different ages (20-82 years) with no history of cardiovascular diseases and diabetes mellitus. All subjects were normotensive, non-smokers with normal blood lipid and glucose values, were not taking any medication at the time of investigation and were asked to refrain from eating and drinking alcohol, coffee or tea 12 hours before the examination. Subjects were divided in two groups (male and female) and 5 age-related groups according to appropriate decade (20-29, 30-39, 40-49, 50-59, and above 60 years). All subjects underwent regular cardiologic examination, ECG recording and cardiac ultrasound in order to exclude valvular diseases, decreased myocardial contractility and ejection fraction. During the study blood pressure and ECG were recorded continuously. Carotid artery intima-media thickness and brachial artery diastolic internal diameter (mm) and blood flow (ml/min) values were measured continuously using high-resolution ultrasound. Brachial artery parameters were measured in baseline condition, during ischaemia and reactive hyperemia (endothelium-dependent relaxation) and after nitroglycerin administration (endothelium independent relaxation, 2 x 400 micrograms, sublingual) [7, 8]. Brachial ischaemia was induced by inflation of a pneumatic tourniquet placed at the forearm to a pressure of 300 mmHg followed by deflation after 3 min. We analyzed changes in peripheral arteries (changes in brachial artery diastolic diameter and flow during 90 sec after cuff deflation), structural changes of carotid artery, functional and structural changes of the left ventricle (19-11). We used cardiac ultrasound (Hewlett Packard Sonos 2500) with a 2.0-2.5 MHz imaging transducer and a 7.0-MHz linear array transducer for vascular measurements. Demographic and clinical characteristics of subjects are presented in Table 1. All results are expressed as mean and S.E.M. Data analysis was done by linear regression analyses, multivariate test (LSD procedure) and Student's T-test. P values less than 0.05 were considered to be significant.
Relative changes in brachial artery diastolic diameter in reactive hyperemia in comparison to aging (with gender distribution) are shown in Graphs 1 and 2. Our study showed decrease in brachial vasodilator response to reactive hyperemia during aging (male p < 0.05, female p < 0.001). Data analysis showed a significant difference between age-related groups above 40 years and groups below 30 years of age (p < 0.001). The analysis of carotid intima-media thickness showed increased values during aging in both genders but without statistical significance (Graph 2). Analysis of relationship between carotid intima-media thickness and aging (by gender) showed a good correlation of these parameters expressed by the following formula: intima-media thickness (cm) = 0.0009 x years of age + 0.0139. ANOVA test for age-related groups showed significant correlation (p < 0.01) between all age-related groups except 30-40 vs. 40-50 year group. Student's T-test showed no significant correlation between genders. The relationship between the left ventricular mass index (LVMI) and aging (with gender distribution) is shown in Graphs 3 and 4. The left ventricular mass index was increased during aging
衰老与内皮血管舒缩功能影响减弱、颈动脉内膜中层厚度增加及僵硬、左心室质量指数增加和血压升高相关[1 - 3]。然而，这些变化在男女两性中的表现方式并不相同[4, 5]。与男性相比，女性在衰老过程中似乎更能免受心血管变化的影响[1, 6]。
本研究旨在评估性别对肱动脉血管舒缩反应（反应性充血试验）的影响，以及与不同年龄健康志愿者血管和心脏重塑的相关性。
本研究针对年龄在20 - 82岁、无心血管疾病和糖尿病病史的健康受试者（n = 66；37名男性，29名女性）进行。所有受试者血压正常、不吸烟，血脂和血糖值正常，在调查时未服用任何药物，且在检查前12小时被要求禁食并避免饮酒、咖啡或茶。受试者按性别分为两组，并根据相应年龄段分为5个年龄相关组（20 - 29岁、30 - 39岁、40 - 49岁、50 - 59岁及60岁以上）。所有受试者均接受常规心脏检查、心电图记录和心脏超声检查，以排除瓣膜疾病、心肌收缩力下降和射血分数降低。研究过程中持续记录血压和心电图。使用高分辨率超声连续测量颈动脉内膜中层厚度、肱动脉舒张内径（mm）和血流（ml/min）值。在基线状态、缺血期间、反应性充血（内皮依赖性舒张）期间以及给予硝酸甘油后（内皮非依赖性舒张，2×400微克，舌下含服）[7, 8]测量肱动脉参数。通过将置于前臂的气动止血带充气至300 mmHg诱导肱动脉缺血，3分钟后放气。我们分析了外周动脉的变化（袖带放气后90秒内肱动脉舒张直径和血流的变化）、颈动脉的结构变化、左心室的功能和结构变化（19 - 11）。我们使用配备2.0 - 2.5 MHz成像探头的心脏超声（惠普Sonos 2500）和用于血管测量的7.0 - MHz线性阵列探头。受试者的人口统计学和临床特征见表1。所有结果均以均值和标准误表示。数据分析采用线性回归分析、多变量检验（LSD程序）和学生t检验。P值小于0.05被认为具有统计学意义。
图1和图2显示了与衰老相关的（按性别分布）反应性充血时肱动脉舒张直径的相对变化。我们的研究表明，衰老过程中肱动脉对反应性充血的舒张反应减弱（男性p < 0.05，女性p < 0.001）。数据分析显示，40岁以上年龄相关组与30岁以下组之间存在显著差异（p < 0.001）。颈动脉内膜中层厚度分析显示，两性在衰老过程中该值均增加，但无统计学意义（图2）。颈动脉内膜中层厚度与衰老（按性别）关系的分析表明，这些参数之间具有良好的相关性，由以下公式表示：内膜中层厚度（cm）= 0.0009×年龄 + 0.0139。年龄相关组的方差分析显示，除30 - 40岁与40 - 50岁组外，所有年龄相关组之间均存在显著相关性（p < 0.01）。学生t检验显示两性之间无显著相关性。图3和图4显示了左心室质量指数（LVMI）与衰老（按性别分布）的关系。衰老过程中左心室质量指数增加
