Hemodynamic Actions of Diuretic Agents

The blood pressure lowering effect of diuretics in hypertensive disease is well documented. The hemodynamic actions underlying this antihypertsive effect differ in the early phase from the effects observed during long-term treatment. This article first describes new experiments on the hemodynamic effects of three diuretics, viz. hydrochlorothiazide, chlorthalidon and furosemide in conscious, chronically instrumented spontaneously hypertensive rats. This animal model was chosen in view of its good applicability for the study of the hemodynamics of antihypertensive drug action. Results show a marked early fall in stroke volume and cardiac index with all three diuretics. Mean arterial blood pressure was decreased only after a delay of several hours, because of an early large increase in total peripheral resistance. This article furthermore discusses possible mechanisms involved in the long-term return of peripheral resistance close to or below pre-treatment values. On the basis of data in the literature it is concluded that adaptation of baroreceptor reflexes, auto-regulatory responses of the peripheral vascular resistance and enhanced production of endogeneous vasodilator substances play an increasingly important role during the long-term hemodynamic actions of diuretic agents.     

Antihypertensive drugs and glucose metabolism

Hypertension plays a major role in the development and progression of micro-and macrovascular disease.Moreover,increased blood pressure often coexists with additional cardiovascular risk factors such as insulin resistance.As a result the need for a comprehensive management of hypertensive patients is critical.However,the various antihypertensive drug categories have different effects on glucose metabolism.Indeed,angiotensin receptor blockers as well as angiotensin converting enzyme inhibitors have been associated with beneficial effects on glucose homeostasis.Calcium channel blockers(CCBs)have an overall neutral effect on glucose metabolism.However,some members of the CCBs class such as azelnidipine and manidipine have been shown to have advantageous effects on glucose homeostasis.On the other hand,diuretics andβ-blockers have an overall disadvantageous effect on glucose metabolism.Of note,carvedilol as well as nebivolol seem to differentiate themselves from the rest of theβ-blockers class,being more attractive options regarding their effect on glucose homeostasis.The adverse effects of some blood pressure lowering drugs on glucose metabolism may,to an extent,compromise their cardiovascular protective role.As a result the effects on glucose homeostasis of the various blood pressure lowering drugs should be taken into account when selecting an antihypertensive treatment,especially in patients which are at high risk for developing diabetes.     

Antihypertensive effects of foods

Hypertension is one of the major risk factors for arteriosclerosis,which leads to cardiovascular disease and stroke.Several clinical trials revealed that control of the blood pressure is useful to reduce the morbidity and mortality associated with these diseases.However,the protective efficacy against these complications still remains at less than 50% even if the high blood pressure is treated by current medical drugs.Healthy diets are expected to not only prevent but also treat lifestyle-related diseases.Improvement of the dietary life,including lowsalt diets,appropriate alcohol consumption,and calorie restriction,is important for the prevention of hypertension.In addition,green tea,which has been drunk on a daily basis in Japan and China since ancient times,possesses an antihypertensive effect,and it was revealed that its components with this effect are catechins.Many studies have been performed on the antihypertensive effects of foods.Therefore,functional foods and their ingredients,reported to possess antihypertensive effects in animal experiments and human clinical trials,are summarized in this review.Blood pressure might be controlled by improvement of the daily eating habits based on evidence regarding these functional foods,and a healthy longevity can be expected.     

社区复方制剂抗高血压治疗研究:2年干预效果分析

目的:观察复方利血平氨苯喋啶片(北京降压0号)和复方利血平片(复方降压片)长期治疗轻、中度高血压的效果、安全性和依从性。方法 :选取2008-10至2009-01北京7个农村社区的轻、中度原发性高血压患者766例,年龄45~75岁,随机分成2组,分别服用北京降压0号(降压0号组,393例)和复方降压片(复降片组,373例),北京降压0号的剂量为0.5~1片/次,1次/d,复方降压片的剂量为1~2片/次,3次/d,观察时间为24个月。结果 :共710例患者完成试验,降压0号组与复降片组患者收缩压/舒张压下降幅度[(24.7±13.9/13.2±8.8)mm Hg vs(23.0±14.2/11.9±9.5)mm Hg,1 mm Hg=0.133 k Pa]、总有效率(89.0%vs 84.5%)、不良反应发生率(0.5%vs 1.34%)差异均无统计学意义(P0.05)。对于2级高血压患者,服药后1、6、12、24个月降压0号组舒张压的下降幅度均高于复降片组,差异有统计学意义(P0.05);降压0号组患者在服药24个月末依从性高于复降片组[(99.2±4.8)%vs(98.2±6.5)%],差异有统计学意义(P0.05)。结论 :北京降压0号依从性和对2级高血压的降压幅度高于复方降压片。两组不良反应差异不明显,均未见明显的不良作用。     

经皮肾神经射频消融术的降压疗效及安全性:附两例报告

交感神经过度兴奋一直被认为是高血压发病的基础环节,其中肾脏交感神经系统对于诱发和保持高血压起着决定性作用.抑制交感神经的过度激活被认为是治疗高血压及其并发症的一个重要靶点,肾交感神经射频消融术(renal sympathetic denervation,RSD)作为一种新型的降压技术,备受广大临床医生关注.RSD通过插入肾动脉的射频导管释放能量,透过肾动脉的内中膜选择性毁坏外膜的肾交感神经纤维,以达到微创治疗顽固性高血压的目的.我们报道两例术后随访超过6个月的高血压患者,以期初步探讨RSD的疗效及安全性.     

缺血性卒中防治中的降压治疗:J曲线现象

心血管病降压治疗中的J曲线现象已有较多理论和试验证据,并已得到大多数学者的认可.而有关缺血性卒中的降压治疗是否存在J曲线现象,相关研究和报道不多,尚未达成共识.文章对该现象进行了综述,期待有助于缺血性卒中的血压管理.     

高血压与肾功能的关系研究

目的探讨高血压控制与肾功能损害加重的关系,为防治肾脏疾病提供依据。方法对2008年1月—2009年12月我院门诊高血压患者960例进行分析。结果血压控制良好组592例,肾功能损害加重90例,加重率15.2%,血压控制不良组368例,肾功能损害加重232例,加重率占63%。结论肾功能损害加重与高血压控制不良有密切关系。     

支架置放术治疗18例肾动脉狭窄

目的　评估支架置放术治疗肾动脉狭窄 (RAS)的疗效与安全性。方法　对 1 8例 ( 1 9例次 )伴有高血压或肾功能不全的RAS≥5 0 %患者 (动脉粥样硬化 7例 ,大动脉炎 4例 ,纤维肌性结构不良 8例次 )进行肾动脉支架置放术 (PTRAS) ,采用门诊方式随访 3～ 41个月 (平均 1 4 5个月 ) ,观察手术对患者血压、肾功能的影响。结果　技术成功率为 1 0 0 % ,未发生并发症 ;术后第 2天疗效 :治愈 6例 ,改善 1 3例次 ;3个月疗效 :治愈 6例 ,改善 1 1例次 ,无效 2例 ;≥ 1 2个月疗效 :共 1 2例 ,治愈 3例 ,改善 9例。结论　RAS≥ 5 0 %者用PTRAS治疗安全、有效 ,对纤维肌性结构不良及大动脉炎患者的疗效较动脉粥样硬化患者好。     

Antihypertensive drugs as predictors of type 2 diabetes among subjects with impaired glucose tolerance

Aims: to examine the incidence rate of progression to Type 2 diabetes and baseline prognostic risk factors, focusing on hypertension and antihypertensive medication, in a cohort (n=207) with impaired glucose tolerance (IGT). Methods: after 2 and 4.6 (1.9–6.4) years new cases of diabetes were diagnosed by the oral glucose tolerance test (OGTT). Hypertension (BP 160/95 or antihypertensive medication) was included in multiple regression analyses to assess the effect of risk factors on the development of diabetes. Results: diabetes developed in 32 subjects (19%), an incidence of 41/1000 (95% CI 28–57/1000) person-years. In univariate analyses, progression to diabetes was associated with a high (>9.0 mmol/l) 2-h OGTT value (P=0.008), a high fasting insulin (>12.0 mU/l) level (P=0.000), a high triglyceride (≥1.3 mmol/l) level (P=0.028), a high BMI (≥28.0 kg/m²) (P=0.013) and hypertension (P=0.003). The risk for the development of diabetes was not increased in hypertensive subjects without antihypertensive medication compared with normotensive subjects (OR 0.8, 95% CI 0.3–2.6). However, it was increased in subjects with on medication, especially diuretics alone or in combination with other drugs. Hypertensive subjects on diuretics had higher levels of fasting insulin and triglycerides and higher BMIs at baseline than normotensive subjects. After adjustment for 2-h OGTT, fasting insulin, triglycerides and BMI, the OR for diabetes was 7.7 (95% CI 2.1–28.2) in hypertensive subjects using diuretics alone or in combination with other drugs and 2.6 (95% CI 1.0–6.7) in those using other drugs compared with normotensive subjects. The OR of diabetes corresponding to a one-unit increase in the 2-h OGTT concentration was 2.5 (95% CI 1.6–4.0) in the whole cohort. Conclusions: the rate of progression from IGT to Type 2 diabetes in this population was similar to that seen in other studies among Caucasian populations. The use of antihypertensive medication, especially diuretics, and a high 2-h OGTT level were significant predictors of subsequent deterioration to diabetes.     

肾老化与老年疾病

为探讨衰老与老年病对肾功能的影响，按纳入标准对８４份小便进行了４种尿微量蛋白的放射免疫法测定。结果发现：尿白蛋白、尿β２－微球蛋白、尿免疫球蛋白Ｇ随增龄或高，而尿Ｔａｍｍ－Ｈｏｒｓｆａｌｌ减少。其中ＵＡｌｂ增多与老年人原发性高血压病和Ⅱ型糖尿病有交互作用。说明老年人存在肾老化现象，老年疾病加速肾老化进程。     

Diuretic window hypothesis in cirrhosis: Changing the point of view

Since the 1970s,non-selective beta-blockers(NSBB)have been used to prevent variceal upper bleeding in advanced cirrhotic patients.However,several recent studies have raised the doubt about the benefit of NSBB in end-stage cirrhotic patients.In fact,they suggested a detrimental effect in these patients that even reduced survival.All of these studies have been assembled to compose the“window therapy hypothesis”,in which NSBB would have traditional indication to be initiated to prevent variceal upper bleeding;however,treatment should be stopped(or not be initiated)in patients with end-stage cirrhosis.NSBB would reduce the cardiac reserve of these patients,worsening systemic perfusion and prognosis.However,it should be emphasized that these studies present important bias issues,and their results also suggested that diuretic treatment may also be behind the effects observed.In this opinion review,we changed the point of view from NSBB to diuretic treatment,based on a physiopathogenic approach of circulatory parameters of cirrhotic patients studied,and based on diuretic effect in blood pressure lowering and in other hypervolemic disease,as heart failure.We suggest a“diuretic window hypothesis”,composed by an open window in hypervolemic phase,an attention window when patient present in a normal plasma volume phase,and a closed window during the plasma hypovolemic phase.