[Effects of 12-week Tai Chi exercise on the microvascular reactivity of the middle-aged and elderly patients with mild hypertension and its mechanism].

Objective: To study the effects of 12-week Taijiquan exercise on the microvascular reactivity of middle-aged and elderly patients with mild hypertension and to explore the mechanisms of microvascular reactivity. Methods: Thirty patients with mild hypertension were divided into exercise group (53.8±6.3 years old) and control group (52.6±7.5 years old). The number and gender ratio of the two groups were the same. The exercise group performed Tai Chi exercise for 12 weeks, and the control group maintained the original lifestyle and did not do other regular sports. The two groups of subjects were tested for microvascular reactivity, blood pressure, serum nitric oxide content, and nitric oxide synthase activity before exercise intervention, 6th week and 12th week, respectively. Results: There was no significant difference in the basic values of each index between the two groups of subjects before the test (P＞ 0.05). In the 6th week, the microvascular reactivity (blood flow increase rate), systolic blood pressure, diastolic blood pressure, nitric oxide content, nitric oxide synthase activity of the exercise group did not significantly change from the basic value (P＞0.05). At the 12th week, the microvascular reactivity, nitric oxide content, c nitric oxide synthase activity were significantly higher than those of the base values and the control group (P＜0.05), but the systolic blood pressure and diastolic blood pressure were significantly lower than those of the base values and control group (P＜0.05). In the control group, there were no significant changes in the 6th and 12th week values of each index from the basic value (P＞0.05). Conclusion: Twelve weeks of Taijiquan exercise can improve the microvascular reactivity of middle-aged hypertensive patients, reduce blood pressure, and increase the nitric oxide content and c nitric oxide synthase of patients. The increase of endogenous nitric oxide production is one of the biological mechanisms of Tai Chi exercise to improve the microvascular responsiveness of hypertension patients.目的:研究12周太极拳运动对中老年轻度高血压患者微血管反应性的影响,并探讨微血管反应性变化的机制。方法:将30名轻度高血压患者分为运动组(53.8±6.3岁)和对照组(52.6±7.5岁),两组人数及性别比例相同。运动组进行12周的太极拳运动,对照组保持原先的生活方式且不做其它规律性的体育运动。两组受试者分别于运动干预前、第6周和第12周结束后进行微血管反应性、血压及血清一氧化氮含量 、一氧化氮合酶活性测试。结果:试验前,两组受试者各指标的基础值均无显著差异(P＞0.05)。运动组,第6周微血管反应性、收缩压、舒张压、一氧化氮含量、一氧化氮合酶活性较基础值无显著变化(P＞0.05),第12周微血管反应性、一氧化氮含量和钙依赖型一氧化氮合酶活性较基础值及对照组显著升高(P＜0.05),收缩压和舒张压较基础值和对照组显著下降(P＜0.05)。对照组,第6周、第12周各指标较基础值均无显著变化(P＞0.05)。结论:12周太极拳运动能提高中老年轻度高血压患者微血管反应性、降低血压,并能提高患者一氧化氮含量、钙依赖型一氧化氮合酶活性,内源性一氧化氮生成增加是太极拳运动提高高血压患者微血管反应性的生物学机制之一。.