Effects of Isometric Handgrip Training on Home Blood Pressure Measurements in Hypertensive Patients: A Randomized Crossover Study

Objective We aimed to examine the effects of isometric handgrip (IHG) training on home blood pressure (BP) levels in hypertensive Japanese patients undergoing treatment. Methods Fifty-three hypertensive patients (mean age, 61.7 years; 56.6% men) with a home systolic BP ≥135 mmHg and/or a home diastolic BP ≥85 mmHg were randomly assigned to either group A or B. As per the crossover design, group A performed 8 weeks of IHG training, followed by an equivalent training-free, control period, while the reverse protocol was performed by group B. The baseline characteristics were similar between both groups. The individualized daily IHG training comprised four sets of 2-min isometric contractions at 30% of the individual’s maximum voluntary contraction capacity, including 1 min of rest between sets, for ≥3 days/week. The outcome measure was morning and evening home BP readings taken over the last 2 weeks of the training and control periods. Results A combined data analysis for both groups showed that IHG training was significantly associated with the lowering of both systolic and diastolic BP in the morning (137.9±9.3 vs. 135.3±9.5 mmHg, p=0.007 and 83.0±9.5 vs. 81.2±9.3 mmHg, p＜0.001, respectively) and evening (130.0±10.7 vs. 127.6±10.1 mmHg, p=0.003 and 75.8±10.4 vs. 73.8±9.2 mmHg, p＜0.001, respectively), while no significant change was observed after the control period. A larger increase in the maximum grip strength due to IHG training was associated with greater BP reductions. Conclusion An 8-week period of IHG training significantly lowered both the morning and evening home BP in hypertensive Japanese patients undergoing treatment.     

The Blood Volume in Pheochromocytoma Patients before and during Treatment with Phenoxybenzamine

ABSTRACT. Total blood volume (TBV), red cell volume (RCV) and plasma volume (PV) were determined in 15 pheochromocytoma patients (9 males and 6 females) prior to and during preoperative treatment with phenoxybenzamine. Seventeen healthy male volunteers served as controls. Untreated male patients did not differ from the controls with respect to TBV, RCV or PV. In the total group of pheochromocytoma patients, phenoxybenzamine, in a dose of 145.6 ± 45.2 (SD) mg/day over 14.3 ± 5.7 (SD) days, induced significant increases in TBV (+9.4%) and PV (+14.5%), whereas RCV remained unchanged. During phenoxybenzamine, the mean PV in male patients significantly exceeded the control mean. We conclude that pheochromocytoma patients adapt their TBV to excessive catecholamine production and that they rarely present with profound hypovolemia. Moderate but higher doses of phenoxybenzamine than previously recommended induced marked increases in TBV secondary to PV expansion. Phenoxybenzamine counteracts the development of hypovolemia most effectively, thereby constituting one of several important measures for successful surgical management of pheochromocytoma patients.     

Quinaprilat-Induced Vasodilatation in Forearm Vasculature of Patients with Essential Hypertension: Comparison with Enalaprilat

The aim of the present study was to assess the possible differences in hemodynamic and neurohumoral responses to local ACE inhibition in the human forearm of patients with essential hypertension with either quinaprilat or enalaprilat. Forearm vascular responses to infusion of quinaprilat or enalaprilat (0.5 g/dL/min) into the brachial artery were studied in 12 male patients with essential hypertension. The experiments were performed in a randomized, double-blind, crossover fashion. Before and during ACE inhibition, the vasoconstrictor response to four cumulative doses of angiotensin I (Ang I) was studied. Forearm blood flow was assessed using venous occlusion plethysmography. Local quinaprilat infusion induced a more rapid (even after 15 minutes; median vasodilation quinaprilat 29% vs. enalaprilat –1%, P > 0.02) and longer lasting forearm vaso-dilation as compared with enalaprilat. After 15 minutes of local ACE inhibition, the vasoconstrictor response to Ang I was completely blocked by both ACE inhibitors. We conclude that in patients with essential hypertension quinaprilat induces a more rapid and longer lasting vasodilatation than enalaprilat. These effects of quinaprilat are possibly related to its higher affinity for vascular ACE. On the other hand, the fact that these effects of quinaprilat were observed despite a similar degree of ACE inhibition as during enalaprilat may suggest that quinaprilat directly stimulates another vasodilatating mechanism.     

Exercise training produces nonuniform increases in arteriolar density of rat soleus and gastrocnemius muscle

OBJECTIVE: Exercise training has been shown to increase regional blood flow capacity to muscle tissue containing fibers that experience increased activity during exercise. The purpose of this study was to test the hypothesis that the increased blood flow capacity is partially the result of increases in arteriolar density (number of arterioles/mm2 of tissue), specifically in skeletal muscle tissue, with the largest relative increase in muscle fiber activity during training bouts. METHODS: This hypothesis was tested by comparing and contrasting the effects of endurance exercise training (ET) and interval sprint training (IST) on arteriolar density in soleus muscle (S) red (Gr) and white (Gw) portions of gastrocnemius muscle of male Sprague Dawley rats. ET rats completed 10 weeks of treadmill training 30 m/min, 15% grade, 60 min/day, 5 days/week, while IST rats completed 10 weeks of IST consisting of six 2.5-min exercise bouts, with 4.5-min rest between bouts (60 m/min, 15% incline), 5 days/week. The hypothesis would be supported if ET increased arteriolar density in S and Gr and if IST increased arteriolar density in Gw. RESULTS: ET increased arteriolar density above values of sedentary rats (SED) in both the Gw (ET = 0.93 +/- 0.19 arterioles/microm2; SED = 0.44 +/- 0.09 arterioles/microm2) and Gr (ET = 0.97 +/- 0.1 arterioles/microm2; SED = 0.51 +/- 0.06 arterioles/microm2) muscles, but not in S (ET = 1.69 +/- 0.45 arterioles/microm2; SED = 1.51 +/- 0.34 arterioles/microm2) muscle. In contrast, IST did not alter arteriolar density in Gw or Gr muscle tissue. Although arterial wall thickness was greater in S (3.95 +/- 0.40 microm) and Gr (6.24 +/- 0.59 microm) than Gw (2.76 +/- 0.18 microm), neither ET or IST altered mean wall thickness in either muscle. CONCLUSION: Increases in blood flow capacity produced in Gr and Gw by ET appear to be due in part to increased arteriolar density. In contrast, increased arteriolar density does not contribute to increased blood flow capacity of Gw in IST rats.     

原发性高血压血压昼夜节律与运动血压的关系

目的 :探讨原发性高血压患者血压昼夜节律与运动血压的关系。方法 :检测 30 3例 1、2级原发性高血压患者的运动血压和动态血压 ,根据夜间血压下降率不同分为杓型组 (n =2 0 0 )和非杓型组 (n =10 3) ,比较两组运动血压各参数 ,并行相关分析。结果 :①非杓型组最大运动量时收缩压、舒张压和运动后恢复期收缩压、舒张压均高于杓型组 ,有极显著性差异(P <0 .0 1或 0 .0 0 1)。②夜间收缩压下降率与最大运动量时收缩压、舒张压存在明显负相关 (γ =-0 40 7、-0 361,P均<0 .0 0 1) ;夜间舒张压下降率与最大运动量时收缩压、舒张压、运动后恢复期收缩压存在明显负相关 (γ =-0 499、-0 479、-0 183,P均 <0 0 1或 0 0 0 1)。结论 :非杓型原发性高血压患者容易出现运动血压过度升高     

Venous Volume and Blood Flow in Hand at Rest and during Psychological Stress in Male Relatives to Hypertensive Patients

ABSTRACT. A total of 19 male relatives to hypertensive individuals were examined with regard to blood flow and venous volume in the hand at rest and during a psychological stress test. They were compared to 19 male controls without heredity for hypertension. There were no significant differences between the groups in hand blood flow or venous volume either at rest or during the test. The increase in vascular resistance during psychological stress was significantly higher in relatives than in controls. Possible mechanisms behind the differences in arterial vascular reactivity between the groups are discussed.     

Effects of melatonin on the thermoregulatory responses to intermittent exercise

We examined the effects of a single 2.5-mg dose of melatonin on the thermoregulatory and circulatory responses to intermittent exercise at a room temperature of 27.2+/-0.4 degrees C (mean+/-S.D.), a relative humidity of 55+/-3% (mean+/-S.D.), and a light intensity of 200-300 lux. In a double-blind cross-over study, six male participants ingested either melatonin or placebo at 11:45 hr. Participants then rested in a semi-supine position for 75 min and completed an intermittent running protocol for 66 min at alternating intensities of 40, 60 and 80% of maximal oxygen uptake. Rectal and mean skin temperature, heart rate, blood pressure, skin blood flow, subjective alertness and sleepiness, ratings of perceived exertion (RPE) and thermal strain were recorded. No effects of melatonin were found on these variables measured during the resting period (P>0.10). During exercise, melatonin was found to moderate the increase in rectal temperature by approximately 0.25 degrees C (P=0.050) and magnify the increase in skin blood flow (P=0.047). Postexercise systolic blood pressure was 7.8+/-2.5 mmHg (mean+/-S.D.) lower than before the exercise in the melatonin trial; a change which differed significantly to that in the placebo trial (P=0.018). Melatonin did not influence subjective alertness and sleepiness before or after exercise and did not change the responses of mean skin temperature, RPE and thermal strain during the exercise (P>0.10). In summary it is apparent that a 2.5-mg dose of melatonin has hypothermic, but not soporific, effects during 66 min of intermittent exercise performed under moderate heat stress. Whether such effects improve endurance athletic performance in hot conditions remains to be confirmed. Our data also suggest that postexercise systolic hypotension is more marked after ingestion of melatonin.     

Effects of Long-Term Treatment with Candesartan on Hemodynamics and Organ Damage in Spontaneously Hypertensive Rats

Summary This study was designed to investigate the effects of candesartan on blood pressure (BP) and blood pressure variability (BPV) reductions, baroreflex sensitivity (BRS) amelioration, and organ protection in spontaneously hypertensive rats (SHR). Methods: Studies were performed in two groups of SHR (n = 13 for control rats; and n = 20 for candesartan-treated rats) and one group of WKY rats (n = 13). Candesartan (3mg /kg/d) was given in rat chow for 4 months. BP was then continuously recorded for 24 hours in conscious state. After the determination of BRS, rats were killed for organ-damage evaluation. Results: Long-term treatment with candesartan significantly reduced BP and BPV expressed by both standard deviation and variation coefficient of BP, enhanced BRS and produced obvious organ protection. Compared with BP level, BPV and BRS values showed a closer or similar relationship with organ-damage parameters in SHR. Multiple regression analysis showed that the decrease in left ventricular hypertrophy was most closely associated with the increase in BRS, whereas the decrease in aortic hypertrophy was most closely associated with the decrease in 24-hour systolic BPV, and the amelioration in renal lesions, with the increase in BRS and the decrease in 24-hour systolic BPV. Conclusion: long-term treatment with candesartan results in organ protection in SHR. Besides BP reduction, the decrease in BPV and the restoration of BRS are significantly related to this organ protection.     

Long-Term Effects of Xuezhikang on Blood Pressure in Hypertensive Patients with Previous Myocardial Infarction: Data from the Chinese Coronary Secondary Prevention Study (CCSPS)

Several previous trials from Western population studies have showed that statins may help reduce blood pressure (BP). However, randomized clinical data is limited. Xuezhikang, a partially extract of red yeast rice, contains a family of naturally occurring statins, and has a marked impact on lipids, but it is unknown whether Xuezhikang has any effect on BP during long-term follow-up in the Chinese population. This is a post-hoc subgroup analysis of a randomized, double-blinded, placebo-controlled, parallel group clinical trial, Chinese Coronary Secondary Prevention Study (CCSPS). A total of 2704 hypertensive patients with previous myocardial infarction (MI) were assigned either to placebo (n == 1341) or to Xuezhikang (n == 1363) daily for an average of 4.5 years. The primary outcome was the unadjusted changes in mean arterial pressure (MAP) from baseline to 6 months. We also assessed systolic blood pressure (SBP), diastolic blood pressure (DBP), and pulse pressure. Analysis of covariance was used to calculate the adjusted effects of treatment on changes in these outcomes at 6, 12, 24, and 48 months post-random- ization, after controlling for potential confounders. This analysis included 2704//4870 (55.5%%) hypertensive patients for whom BP was measured at baseline and at least one follow-up visit after randomization. Median duration of the follow-up was 4.5 years (54 months), and 25 patients (0.92%%) were lost to the last follow-up because of adverse effects. The results showed that the unadjusted and adjusted changes in MAP, SBP, DBP, or pulse pressure from baseline were not significantly different for Xuezhikang or placebo recipients at 6, 12, 24, and 48 months after randomization. In this post-hoc subgroup analysis, we failed to demonstrate any significant reducing effects of Xuezhikang on BP in Chinese hypertensive patients with previous MI, suggesting that further prospective study on the effects of statins on BP would be needed, especially in high-risk patients.     

动态血压监测比较吲哒帕胺和氨氯地平治疗高血压病疗效

目的了解评价吲哒帕胺降压效果并与氨氯地平比较。方法随机选择轻中度的Ⅱ期高血压病１２例，其中６例先予服吲哒帕胺（２．５～５ｍｇ／ｄ），另６例先服氨氯地平（５～１０ｍｇ／ｄ），治疗８周后停药２周，交叉服氨氯地平或吲哒帕胺８周。服每一种药前及８周均行２４小时动态血压监测，并同时监测偶测血压。结果两药治疗后２４小时血压均值、昼间血压均值、夜间血压均值和相应的血压负荷值均显著降低（Ｐ＜０．０１）。两药治疗前后夜间和白昼血压均值比明显下降（Ｐ＜０．０１）。降压效应谷峰比值，两药均＞０．５，但氨氯地平高于吲哒帕胺（Ｐ＜０．０５）。偶测血压监测两药的有效率相似，总有效率均１００％，治疗后血压相显著下降。结论吲哒帕胺和氨氯地平均可持续地控制２４小时血压并具有良好的谷峰比，以及纠正异常的昼夜血压节律作用。但吲哒帕胺价格便宜，故推荐可做为优选的降压药物。     

Focus on blood pressure levels and variability in the early phase of acute ischemic stroke with hypertension and carotid stenosis

To investigate the optimal blood pressure (BP) levels and relative importance of BP and BP variability in the early phase of acute ischemic stroke (AIS) for hypertensive patients with carotid artery stenosis (CAS). A single‐center cohort study included 750 AIS patients with hypertension and tests were performed for CAS. Participants were categorized to Group 1 (SBP < 140 mm Hg and DBP < 90 mm Hg), Group 2: (SBP: 140–159 mm Hg and or DBP: 90–99 mm Hg), and Group 3: (SBP ≥160 mm Hg and/or DBP ≥100 mm Hg) according to the guidelines. The associations of mean BP levels and variability with outcomes (recurrent stroke, all‐cause death and the composite cardiovascular events) at 6 months were analyzed by Cox proportional hazard models. The associations of BP variability with BP levels and cerebral blood flow (CBF) were analyzed by linear regression and generalized additive models. Both for primary and secondary outcome, more events occurred in Group 1 compared with Group 2, while no significant difference was found in Group 3 with higher BP levels. Lower systolic BP variability showed better prognosis and higher CBF. The associations were more significant in patients with CAS ≥50%. BP variability exhibited a linear negative relationship with BP levels. In the early phase of AIS with hypertension and CAS, maintaining low blood pressure variability may be important to improve outcomes while low BP levels (SBP/DBP < 140/90 mm Hg) were harmful, especially in those patients with CAS ≥ 50%.     

一氧化氮和前列腺素在门静脉高压性胃病大鼠胃粘膜灌注中的作用

目的 探讨一氧化氮（NO）和前列腺素在门静脉高压性胃病（PHG）大鼠胃粘膜灌注中的作用。方法 部分结扎大鼠门静脉主干2周后,采用中性红清除率法测定大鼠胃粘膜血流量（GMBF）,同时观察门静脉压力（PVP）的变化。结果 PHG组大鼠GMBF和PVP显著高于假手术组（t=3.431、3．312,P＜0．01）。低剂量的NO合成酶抑制剂L－硝基－精氨酸甲酯（L－NAME）呈剂量依赖性降低PHG大鼠GMBF,而对假手术组GMBF无明显影响;高剂量的L－NAME（12mg/kg)能非常显著降低PHG和假手术组大鼠GMBF。前列腺素环氧合酶抑制剂消炎痛能明显降低PHG组大鼠GMBF,而对假手术组GMBF无明显影响;预先给消炎痛处理后在假手术组大鼠中,静脉注射低剂量L－NAME（4mg/kg)前后GMBF无明显变化,高剂量L－NAME（12mg/kg)降低大鼠的GMBF与未用消炎痛处理组比无明显变化;预先给消炎痛处理后在PHG组大鼠中,L－NAME剂量（4mg/kg、12mg/kg)依赖性降低大鼠的GMBF与未用消炎痛处理组比无明显改变。结论 NO、前列腺素在调节PHG大鼠的GMBF起重要作用,但两者无协同作用。     

高血压患者心肌微循环损伤与运动试验中血压和心率变化的相关性研究

目的 探讨高血压患者心肌微循环损伤与运动试验中血压、心率变化的关系.方法 选取住院的高血压患者74例,根据心肌声学造影实时评估心肌微循环灌注,分为微循环显像正常组和异常组.搜集研究对象一般临床资料、生化指标和平板运动参数等指标.比较两组患者各指标间的差异,分析高血压患者心肌微循环与运动后血压、心率的关系.结果(1)高血...     

Relationship Between Blood Pressure and Urinary Albumin Excretion Rate in Young Danish Type 1 Diabetic Patients: Comparison to Non-diabetic Children

In 1989 a nation-wide investigation of blood pressure and urinary albumin excretion rate (AER) was carried out in 506 boys and 441 girls with Type 1 diabetes (approximately 80 % of total) treated at 22 paediatric departments. In addition a reference population from 1979 consisting of 663 healthy non-diabetic children (334 boys, 329 girls) served as a control group with respect to blood pressure and body mass index. Microalbuminuria was defined as AER of 20–150 μg min^-1 in at least two out of three timed overnight urine collections and was diagnosed in 30 adolescents (16 boys, 14 girls). Five patients (3 boys, 2 girls) had overt proteinuria (AER: > 150μg min^-1). Age-related percentile charts based on one blood pressure reading were provided for normoalbuminuric diabetic patients and the healthy control group. The study revealed an increase in arterial blood pressure during the period of the pubertal growth spurt for the diabetic and non-diabetic group. The changes were most pronounced for systolic blood pressure. No statistically significant difference was observed in systolic and diastolic blood pressure between normoalbuminuric diabetic children and healthy control children. However, diabetic females aged 15–18 years had significantly higher diastolic blood pressure (75 ± 1 mmHg, n = 139, mean ± SE) than healthy control females (72± 1 mmHg, n = 155, p ± 0.01), and significantly (p ± 0.001) higher body mass index (diabetic females: 22.3± 0.2 kg m^-2 vs healthy females: 20.9± 0.2 kg m^-2, mean± SE). Boys aged from 15 to 18 years with Type 1 diabetes had significantly higher systolic blood pressure (123± 1 mmHg, n = 164) than girls (117± 1 mmHg, n = 139, p± 0.0001), while girls aged from 15 to 18 years had significantly higher diastolic blood pressure (75± 1 mmHg, n = 139) than boys (72± 1 mmHg, n = 72, p ± 0.01). Among the 30 adolescents with persistent microalbuminuria, 18 (10 boys, 8 girls) had diastolic blood pressure above the upper quartile for normoalbuminuric patients, while 2 out of 5 with macroalbuminuria had diastolic blood pressure above this limit. By multiple logistic regression the only risk determinants for elevated urinary albumin levels were age and diastolic blood pressure. These findings suggest that elevated arterial blood pressure is related to the increased prevalance of microalbuminuria observed in adolescents with Type 1 diabetes.     

Exercise as a provocative test in early renal disease in Type 1 (insulin-dependent) diabetes: albuminuric,systemic and renal haemodynamic responses

Summary The value of exercise as a provocative test for early renal disease in Type 1 (insulin-dependent) diabetes was reevaluated. Three carefully characterized groups of males were studied: 10 non-diabetic controls, 16 diabetic patients (group 1) with normal urinary albumin excretion (< 15 g/min) and 14 Albustix-negative diabetics (group 2) with increased urinary albumin excretion (15–122 g/min). Assignment to a study group was made on the basis of three 24-h urine collections, and the groups were well matched for age, weight, height, and serum creatinine concentration. The two diabetic groups were similar with regard to duration of disease (13±6 versus 16±3 years), metabolic control (HbA_1c: 8.4±1.4 versus 8.7±1.3%) and degree of diabetic complications (beat-to-beat variation and retinopathy). An exercise protocol of 450 and 600 kpm/min workloads was employed. In the resting state group 2 patients had elevated systolic blood pressure compared with the normal subjects (132±13 versus 119±9 mmHg), and their glomerular filtration rate was significantly reduced compared with group 1 (123±19 versus 138±15ml/min per 1.73m², p < 0.05). During exercise the urinary albumin excretion rate increased significantly in all three groups (normal subjects: 6±0.7 to 8±1.3 (g/min); group 1: 6±0.6 to 9±1 g/min and group 2: 48±10 to 113±23 g/min), the relative increase being higher in group 2 (p < 0.01). The changes in systemic haemodynamics were similar in all three groups in spite of a reduced maximum working capacity in group 2 (949±249 versus group 1:1163±200 and normal subjects 1267±264 kpm/min (p < 0.05). The renal haemodynamic changes were qualitatively similar for the three groups, but the filtration fraction during exercise increased in groups 1 and 2 to almost identical values and were significantly higher than in normal subjects (group 1 + group 2: 0.29±0.02 versus normal subjects: 0.26±0.03, p < 0.02). These findings suggest that an elevated transcapillary pressure gradient, as obtained during moderate exercise, will not cause an abnormal increase in albumin excretion per se. A functional glomerular lesion, already recognisable at rest (elevated albumin excretion) must also be present.     

Effects of Long-Term Tenofovir and Entecavir Treatment on Bone Mineral Density in Patients with Chronic Hepatitis B

BackgroundWe aimed to investigate the long-term effects of tenofovir disoproxil fumarate and entecavir treatment on bone mineral density and evaluated the fracture risk assessment tool score in patients with chronic hepatitis B.MethodsA total of 58 chronic hepatitis B patients treated with tenofovir disoproxil fumarate (n = 40) and entecavir (n = 18) were included in this prospective study from 2012 to 2016. To evaluate bone mineral density, dual-X-ray absorptiometry, fracture risk assessment tool, and laboratory examinations were performed in all patients first at baseline and second at the end of the study.ResultsAge, sex, body mass index, fibrosis score, and viral load were similar in both groups. The mean follow-up was 33 months in the tenofovir disoproxil fumarate group and 31 months in the entecavir group. In patients treated with entecavir, there was no statistically significant difference between baseline and second bone mineral density including lumbar spine (L) and total hip T score. In patients treated with tenofovir disoproxil fumarate, there was a significant difference in the second bone mineral density compared with baseline bone mineral density for L3 (P = .033) and the major fracture risk assessment tool score (P = .03). When patients were divided into 3 groups (normal bone mineral density, osteopenic, and osteoporotic), there was a significant increase in the number of osteopenic patients in the total hip T score after tenofovir disoproxil fumarate treatment (P = .034).ConclusionOur results suggest a decrease in the bone mineral density for lumbar spine (L3), an increase in the number of patients with hip osteopenia, and major fracture risk assessment tool score after long-term tenofovir disoproxil fumarate treatment in patients with rechronic hepatitis B.     

Influence of Heart Rate and Atrioventricular Synchronization on Maximal Work Tolerance in Patients Treated with Artificial Pacemakers

ABSTRACT In 14 patients with symptomatic high-degree AV block, studies were carried out of the effect on physical working capacity when an atrial triggered mode of cardiac pacing (VAT) was substituted for ventricular inhibited pacing (VVI). The tests were designed to elucidate the quantitative relationship between the effect of rate increase and AV synchronization by comparing VVI pacing matched to the same rate as VAT. The work load was increased by 10 W/min. The physical working capacity increased by 25 % with VAT as compared with VVI (p<0.001). The improvement was entirely attributed to heart rate increase, and not to AV synchronization.