Impact of Dialysate Sodium Concentration Lowering on Home Blood Pressure Variability in Hemodialysis Patients

Blood pressure variability is an independent risk factor for mortality and cardiovascular events in hemodialysis patients. Dialysate sodium concentration may not only have effects on blood pressure but also on blood pressure variability. We investigated whether dialysate sodium concentration lowering could decrease home blood pressure variability in hemodialysis patients. Forty‐three hemodialysis patients at their dry weight assessed by bioimpedance methods with pre‐dialysis serum sodium >136 mmol/L were recruited. Firstly, patients underwent a 1‐month standard dialysis with dialysate sodium concentration of 138 mmol/L, and then the dialysate sodium concentration was decreased to 136 mmol/L for 8 weeks. Home blood pressure was assessed on waking up and at bedtime for 1 week. Coefficient of variation was used to define home blood pressure variability. After the intervention, whole‐day systolic blood pressure variability decreased from 5.7 ± 2.6% to 4.3 ± 1.7% and evening systolic blood pressure variability decreased from 7.9 ± 4.1% to 6.2 ± 3.1%. Morning systolic blood pressure variability had a reduction from 7.8 ± 2.4% to 5.9 ± 3.3% but did not achieve statistical significance (P = 0.077). Whole‐day, morning and evening systolic blood pressure were decreased significantly. Less changes were observed in diastolic blood pressure parameters. Interdialytic weight gain mildly but significantly decreased. Volume parameters, dietary sodium intake and incidence of adverse events were similar throughout the study period. Lowering dialysate sodium concentration could improve home blood pressure variability among hemodialysis patients who had achieved their dry weight.     

The use of peridialysis blood pressure and intradialytic blood pressure changes in the prediction of interdialytic blood pressure in haemodialysis patients

OBJECTIVE: It is uncertain which blood pressure values (pre- or post-haemodialysis) best represent the average daily blood pressure in haemodialysis patients. The purpose of this study was to verify the power of peridialysis blood pressure to predict interdialytic blood pressure, and to ascertain the influence of blood pressure fluctuations during dialysis on this predictive ability. METHODS AND RESULTS: We performed ambulatory blood pressure monitoring during the interdialytic period on 60 stable haemodialysis patients (mean age 53 +/- 16 years, 33 male) between two mid-week haemodialysis sessions. Pre- and post-haemodialysis blood pressures were 154/82 and 142/77 mmHg, respectively, and 44-h interdialytic blood pressure was 136/77 mmHg. Overall, post-haemodialysis blood pressure values correlated with interdialytic ambulatory blood pressure marginally better than did pre-haemodialysis values (r = 0.52 versus 0.61 for pre- and post-dialysis systolic pressure, respectively; r = 0.67 versus 0.72 for pre- and post-dialysis diastolic pressure, respectively). The average of the pre- and post-haemodialysis values showed a slightly better correlation with interdialytic blood pressure (r = 0.65 and 0.75 for systolic and diastolic pressure, respectively). When we stratified patients according to systolic blood pressure behaviour during dialysis, pre-dialysis blood pressure was the stronger predictor of interdialytic blood pressure in the quartile with greatest intradialytic blood pressure fall (r = 0.67 versus 0.44 for pre- and post-dialysis systolic blood pressure, respectively), whereas post-dialysis values were substantially better in the group with a rise in systolic pressure during dialysis (r = 0.26 versus 0.59 for pre- and post-dialysis systolic blood pressure, respectively). CONCLUSIONS: These data demonstrate that peridialysis blood pressure values are of limited accuracy in predicting interdialytic blood pressure, post-dialysis values are minimally better predictors than pre-dialysis blood pressures, and the average of pre- and post-haemodialysis values is marginally better than both. In addition, blood pressure fluctuations during dialysis have a sizable impact on this predictive ability. Clinical decisions related to blood pressure management and research design in haemodialysis hypertension should take these factors into account.     

Lack of effect of percutaneous transluminal renal angioplasty on nocturnal hypotension in renovascular hypertensive patients

OBJECTIVE: To investigate whether nocturnal blood pressure fall is blunted in renovascular hypertension and can therefore be used as a diagnostic criterion for this condition. METHODS: In 14 renovascular hypertensive patients (age 43.8+/-2.1 years, mean+/-SEM, clinic blood pressure 173.6+/-3.7 mmHg systolic and 109.0+/-2.0 mmHg diastolic) and in 14 age- and blood pressure-matched essential hypertensive controls 24 h ambulatory blood pressure was measured after washout from drug treatment, during angiotensin converting enzyme inhibitor treatment and, in renovascular hypertension, also after percutaneous transluminal renal angioplasty. RESULTS: The 24 h average systolic and diastolic blood pressures were 146.4+/-5.7 and 97.5+/-3.6 mmHg in renovascular and 144.3+/-1.2 and 98.0+/-2.2 mmHg in essential hypertensive patients. The angiotensin converting enzyme inhibitor treatment reduced 24 h average systolic and diastolic blood pressures by 8.5% and 9.7% in the renovascular and by 8.3% and 10.8% in the essential hypertensive group. Greater systolic and diastolic blood pressure reductions (-18.2% and -18.1%) were observed in renovascular hypertensive patients after percutaneous transluminal renal angioplasty. Blood pressure fell by about 10% during the night and the fall was similar in renovascular and in essential hypertensive patients. In the former group, nocturnal hypotension was similar after washout, during angiotensin converting enzyme inhibitor treatment and after percutaneous transluminal renal angioplasty. Similar results were obtained for nocturnal bradycardia. CONCLUSIONS: Nocturnal blood pressure fall is equally manifest in renovascular and essential hypertension. The removal of the renal artery stenosis and blood pressure normalization do not enhance this phenomenon. Nocturnal hypotension seems therefore to be unaffected by renovascular hypertension.     

Myths and reality concerning hypertension in peritoneal dialysis patients: results of a multicenter study

OBJECTIVES: To evaluate the prevalence of hypertension, the average blood pressure level, the 24 h blood pressure profile, and the efficacy of antihypertensive therapy for a large population of peritoneal dialysis patients.DESIGN: A cross-sectional, observational multicenter study. METHODS: From 504 peritoneal dialysis patients (18% of the Italian peritoneal dialysis population) involved in a multicenter observational study, we selected 414 who had undergone successful ambulatory blood pressure monitoring (i.e. no hours with data absent, >/= 75% successful readings and monitoring duration >/= 24 h). Office blood pressure measurements and ambulatory blood pressure monitoring were performed for each patient on the same day with a standard mercury sphygmomanometer and a SpaceLabs 90207 device, respectively.RESULTS: According to World Health Organization/International Society of Hypertension criteria, 44 peritoneal dialysis patients (10.6%) were normotensive and 370 patients (89.4%) were hypertensive, 304 (82.1%) of whom were being administered antihypertensive therapy. Daytime systolic and diastolic blood pressures were both significantly lower than office systolic and diastolic blood pressures (140.7 +/- 19.7/72.1 +/-11.1 versus 148.3 +/- 23.6/85.6 +/- 12 mmHg; P < 0.001). The difference between office blood pressure and daytime blood pressure was significantly correlated to office blood pressure (P < 0.001 for systolic and P < 0.001 for diastolic). The diurnal blood pressure rhythm evaluated by visual inspection of hourly mean plots was not influenced by sex, age, antihypertensive treatment, and peritoneal dialysis modality. Systolic and diastolic blood pressures exhibited a day-night mean decreases of 8.6 +/- 11.7 and 7.7 +/- 6.9 mmHg, respectively, and daytime blood pressure values were significantly higher than night-time ones (P < 0.001). Two hundred and twenty patients (53.1%) were nondippers according to O'Brien's criteria, 247 patients (59.7%) were nondippers according to Verdecchia's criteria, and 269 patients (65.0%) were nondippers according to Staessen's criteria. Only 39 patients (9.4%) had a reversed circadian rhythm. The day-night differences of systolic and diastolic blood pressures were in a unimodal distribution. Among hypertensive patients not being administered antihypertensive therapy, only six patients ( five women and one man) had white-coat hypertension. Among hypertensive patients being administered antihypertensive therapy, 235 patients (77.3%) had 24 h blood pressure loads > 30%.CONCLUSION: There is a high prevalence of hypertension among peritoneal dialysis patients. White-coat hypertension is very rare in this population. Despite the extensive use of antihypertensive therapy, control of blood pressure is maintained in a large number of our peritoneal dialysis patients. Any classification of patients into dipers and nondippers must be interpreted cautiously.     

Assessment of salt intake in hemodialysis

One of the main goals of dialysis is to reach a correct sodium balance. Dietary sodium restriction facilitates control of thirst, water overload, hypertension and cardiac failure. Nowadays, it is possible to estimate sodium mass transfer and known interdialytic salt intake, by means of non-invasive methods. The use of dialysate sodium profiles improves dialysis tolerance but it has been reported that interdialytic thirst may increase because of an inappropriate sodium balance. The aim of this study was to evaluate the usual salt intake in hemodialysis patients, the effects on interdialytic gain weight, arterial pressure, blood volume preservation and dialysis tolerance of two different profiles of dialysate sodium and an additional session with salt restriction. Seventeen dialysis patients, 12 male and 5 females, were studied. Each patient underwent seven hemodialysis treatments: three consecutives sessions (a week) with constant sodium and ultrafiltration hemodialysis; three consecutive sessions with exponential decrease of conductivity (Initial 15.5-16.0, mid-session 14.3 and at the end 13.9-14 mS/cm) and ultrafiltration (1.6 l/h initial and 0.1 at the end) profiled hemodialysis; and an additional session which had a special dietary salt restriction. Dialysis parameters and dry weight were kept constant. Integra monitor with Diascan and Hemoscan biosensors (Hospal) were used in all sessions. We measured pre- and postdialytic plasma conductivity, sodium mass transfer, interdialytic weight gain, mean arterial pressure (MAP), percent reductions of blood volume (%R-BV) and hypotensive episodes during dialysis. Mean sodium mass transfer was 1,144 +/- 356 mmol (no profile week) vs 1,242 +/- 349 mmol (week with profiles), NS. It was equivalent to a salt ingestion of 9.6 +/- 3 and 10.4 +/- 3 g/day respectively. End plasma conductivity was 14.04 +/- 0.14 (no profile) versus 14.21 +/- 0.08 mS/cm (profiled), p < 0.001. Interdialytic weight gain was 2.49 +/- 0.76 (no profile) vs 2.32 +/- 0.56 kg (profiled), NS. MAP was 101 +/- 11 (no profile) vs 99 +/- 10 mmHg (profiled), NS. The %R-BV was -7.73 +/- 3 (no profile) vs -6.46 +/- 3% (profiled), p < 0.01. Hypotensive episodes/session were 0.66 +/- 0.75 (no profiles) vs 0.41 +/- 0.57 (profiled), NS. Mean sodium mass transfer was 356 +/- 125 mmol with usual salt intake and 240 +/- 81 mmol with salt restriction, p < 0.001. It was equivalent to a salt ingestion of 10.47 +/- 3 versus 7.06 +/- 2 g per day respectively, p < 0.001. Initial plasma conductivity was 14.31 +/- 0.21 (usually sodium intake) versus 14.16 +/- 0.17 mS/cm (salt restriction), p < 0.01. Predialysis blood pressures were decreased with dietary salt restriction, MAP was 99.1 +/- 11 vs 94.4 +/- 12 mmHg (p < 0.01). Interdialytic weight gain decreased with salt restriction, 2.32 +/- 0.76 vs 1.78 +/- 0.49 kg (p < 0.001). The %R-BV was -7.25 +/- 2 (usual sodium intake) vs -5.91 +/- 2% (salt restriction), p < 0.01. Hypotensive episodes/session were 0.71 +/- 0.8 (usual sodium intake) vs 0.18 +/- 0.5 (salt restriction), p < 0.05. In conclusion, automatic measurement of sodium mass transfer is a practical tool to follow dietary salt ingestion in hemodialysis patients. It allows us accurate, individualised and continual dietary interventions. The use of exponential decrease sodium profiles improve dialysis tolerance without changes in sodium balance, interdialytic weight gain or arterial pressure. A reduction of three g in salt intake observed in this study was beneficial in interdialytic weight gain, dialysis tolerance and blood pressure control.     

枸橼酸碳酸氢盐透析液对血液透析患者高血压的影响

目的:比较枸橼酸碳酸氢盐透析液与普通碳酸氢盐透析液治疗维持性血液透析患者透析中血压的影响。方法:20例患者随机分为两组,各10例,分别使用枸橼酸碳酸氢盐透析液和普通碳酸氢盐透析液进行透析,第一组患者使用普通碳酸氢盐透析液治疗4周后切换为枸橼酸碳酸氢盐透析液治疗4周。第二组患者直接切换为枸橼酸碳酸氢盐透析液治疗4周后再次切换成普通碳酸氢盐透析液治疗4周。记录透析前后及透析过程中的实验室数据进行统计分析。结果:(1)使用枸橼酸碳酸氢盐透析液的患者透析过程中患者的平均收缩压明显低于普通碳酸氢盐透析液透析时(P0.01),平均动脉压(MAP)较普通碳酸氢盐透析液透析时降低(P0.05);枸橼酸碳酸氢盐透析液透析时患者透析中高血压的发生率为3.3%,明显低于使用普通碳酸氢盐透析液透析时(20%,P0.01)。(2)使用不同透析液透析时患者透析前血清总钙离子与离子钙水平无统计学差异,枸橼酸碳酸氢盐透析液透析时患者透析后血清总钙离子和离子钙水平明显著低于普通碳酸氢盐透析液透析时(P0.01)。普通碳酸氢盐透析液透析时患者透后血清总钙离子及离子钙水平较透前显著升高(P0.01),使用枸橼酸碳酸氢盐透析时患者仅出现透后血清离子钙水平下降(P0.01),而透析前、后血清总钙离子水平无明显改变。(3)不同透析液透析前、后BUN均无统计学差异。虽然枸橼酸碳酸氢盐透析液透析时患者尿素清除指数(Kt/V)要略高于普通碳酸氢盐透析液透析时,但两者之间无统计学差异。两组患者均未出现严重的低血压、低钙血症及抽搐等不良反应。结论:应用枸橼酸碳酸氢盐透析液治疗的患者透析中血压的控制明显优于普通碳酸氢盐透析液。其血压控制佳、高血压发生率低,无严重低血压、抽搐以及碱中毒等不良反应。透析后离子钙浓度减低,但并未发生明显低钙血症。证实了其在临床应用的有效性和安全性。     

Control of blood pressure and prevention of end-organ damage in patients with accelerated hypertension by combination with arotinolol and extended release nifedipine.

In patients with accelerated (malignant) hypertension, end-organ damage is the determinant factor for prognosis. Although recent advances in antihypertensive therapy have improved the outcome of patients with accelerated hypertension, the effectiveness of antihypertensive therapy still remains less convinced. In this study, we followed 13 patients clinically diagnosed with accelerated hypertension (defined as diastolic blood pressure > 130 mmHg, retinopathy with K-W IV and accelerated renal impairment) for 3 yr. One patient died due to acute myocardial infarction arising from poor compliance with antihypertensive therapy. One patient was maintained on hemodialysis for 3 yr. One patient was introduced for continuous ambulatory peritoneal dialysis (CAPD) for a year and then lived without dialysis therapy. The remaining 10 patients were followed for 3 yr. All patients were initially treated with intravenous administration of calcium antagonist for reduction of blood pressure, followed by hemodialysis therapy if needed. After stabilization of blood pressure, combination therapy with extended release nifedipine (40 to 80 mg daily) and arotinolol (20 mg daily) was started. The targets for blood pressure control were a systolic pressure of 135 mmHg and a diastolic pressure of 80 mmHg. If blood pressure control was unsatisfactory, guanabenz (2 to 4 mg before bedtime), a central acting drug, was added. At presentation, the mean diastolic blood pressure (mDBP) among the 10 remaining patients was 134 +/- 2 mmHg, the mean serum creatinine (mScr) was 4.5 +/- 0.7 mg/dl and the left ventricular mass index (LVMi) as measured by echocardiography was 150 +/- 9 g/m2. At 1 yr, the mDBP was reduced to 90 +/- 3 mmHg, the mScr to 2.9 +/- 0.9 mg/dl and the LVMi to 140 +/- 9 g/m2. At 3 yr, the mDBP was stabilized at 79 +/- 3 mmHg, the mScr maintained at 2.2 +/- 0.4 mg/dl, and the LVMi reduced to 128 +/- 9 g/m2. These results indicate that appropriate blood pressure control is important for improvement of renal impairment and cardiac damage in patients with accelerated hypertension. Moreover, combination therapy with arotinolol and extended release nifedipine may be beneficial for this purpose.     

Interrelation between arterial hypertension and body mass index in patients with concomitant ischemic heart disease treated with cardiac rehabilitation

A goal of the study was to investigate the interrelations between body mass index (BMI) and arterial pressure level and its alterations induced by a long-term cardiac rehabilitation. In the patients with arterial hypertension with concomitant ischemic heart disease (IHD). The study group consisted of 73 patients (46 males and 27 females), with age range 54-64 years (the mean: 59.59 +/- 0.67 years), subjected to the 6-month ambulatory supervised cardiac rehabilitation, which comprised stamina training with cycloergometer combined with generally improving exercises. Arterial pressure level was measured in the resting state (just before the training onset) and at the interval training peak (peak pressure) during the consecutive three initial and three final training sessions. Upon completion of the rehabilitation cycle, statistically significant reduction of resting systolic pressure: 116.85 +/- 1.68 mmHg vs 105.12 +/- 1.43 mmHg (p<0.01) and insignificant reduction of resting diastolic pressure 79.85 +/- 1.24 mmHg vs 77.44 +/- 1.21 mmHg (NS) were observed. Additionally, insignificant lowering both systolic and diastolic peak pressure was noted, respectively: 119.45 +/- 1.92 vs 118.75 +/- 2.3 mmHg and 78.63 +/- 1.22 mmHg vs 76.96 +/- 1.30 mmHg. Correlation analysis concerning the values of resting systolic and diastolic pressure, likewise of peak systolic and diastolic pressure, on the one hand, and the values of body mass index, on the other hand, yielded in the all considered cases the statistically insignificant positive Pearson's coefficients. The further dependence analyzed, between the delta of resting and peak pressure, systolic and diastolic, and the body mass index values was featured by the insignificant statistically negative correlation coefficients. In result of the 6-month rehabilitation, 36 out of 73 patients demonstrated BMI value reduction by 0.65 +/- 0.33, which did not affect significantly an extent of the arterial pressure lowering. Therefore, in the examined patient group with hypertension and IHD, body mass index turned out to determine neither the initial nor the after-rehabilitation pressure levels, both systolic and diastolic.     

Refractory hypertension and sleep apnoea: effect of CPAP on blood pressure and baroreflex.

This study was undertaken to determine whether abolition of obstructive sleep apnoea (OSA) by continuous positive airway pressure (CPAP) could reduce blood pressure (BP) in patients with refractory hypertension. In 11 refractory hypertensive patients with OSA, the acute effects of CPAP on nocturnal BP were studied during sleep and its longer term effects on 24-h ambulatory BP after 2 months. During a single night's application, CPAP abolished OSA and reduced systolic BP in stage 2 sleep from 138.3 +/- 6.8 to 126.0 +/- 6.3 mmHg. There was also a trend towards a reduction in average diastolic BP (from 77.7 +/- 4.5 to 72.9 +/- 4.5). CPAP usage for 2 months was accompanied by an 11.0 +/- 4.4 mmHg reduction in 24-h systolic BP. In addition, both the nocturnal and daytime components of systolic BP fell significantly by 14.4 +/- 4.4 and 9.3 +/- 3.9 mmHg, respectively. Diastolic BP was reduced significantly at night by 7.8 +/- 3.0 mmHg. In patients with refractory hypertension, acute abolition of obstructive sleep apnoea by continuous positive airway pressure reduces nocturnal blood pressure. These data also suggest that continuous positive airway pressure may reduce nocturnal and daytime systolic blood pressure chronically. Randomised trials are needed to confirm the latter results.     

Modest salt reduction lowers blood pressure in isolated systolic hypertension and combined hypertension

Many randomized trials have shown that a reduction in salt intake lowers blood pressure in hypertensive individuals. However, few have looked at the effects according to hypertension category. A recent analysis of the third and fourth National Health and Nutrition Examination Survey suggests that salt intake may not be related to blood pressure in isolated systolic or combined hypertension. To look at this further, we reanalyzed the data of our previous salt reduction trials. Hypertensive individuals were studied in randomized double-blind crossover studies: 1 month of usual salt intake compared with 1 month of reduced salt intake. In isolated systolic hypertension (n=24), blood pressure was reduced from 166+/-19/86+/-7 to 156+/-20/85+/-7 mm Hg (systolic P<0.001; diastolic P=0.459) with a reduction in urinary sodium from 175+/-51 to 87+/-38 mmol per 24-hour period (10.3 to 5.1 g per day of salt). In combined hypertension (n=88), blood pressure was reduced from 161+/-16/100+/-9 to 154+/-17/96+/-9 mm Hg (P<0.001) with a reduction urinary sodium from 176+/-65 to 98+/-51 mmol per 24-hour period (10.4 to 5.8 g per day of salt). These results demonstrate that salt reduction has a significant effect on blood pressure in isolated systolic and combined hypertension. The fall in systolic observed in isolated systolic hypertension would be predicted to reduce stroke by approximately one third, ischemic heart disease by one quarter, and heart failure by one quarter in the population between 60 and 80 years of age, in whom isolated systolic hypertension is the predominate form of hypertension and carries the highest risk. These results provide strong support for universal salt reduction in all hypertensives.     

Randomised blind controlled trial of a high fibre, low fat and low sodium dietary regimen in mild essential hypertension

Thirty-four patients with essential hypertension were allocated, in a controlled trial, to a treatment diet of high fibre, low fat and low sodium composition, or to a control diet by the hospital dietitian. Clinical observations were made by a separate 'blinded' nursing sister. After three months treatment, the modified diet-treated group showed a significant reduction in mean systolic (169.4 +/- 23.4 to 150.6 +/- 16.1 mmHg) and diastolic blood pressure (101.5 +/- 7.3 to 89.4 +/- 6.8 mmHg), accompanied by significant reductions in urinary sodium excretion (140.4 +/- 34.6 to 93.7 +/- 44 mmol/day) and weight (73.1 +/- 10 to 71.2 +/- 8.4 kg). The changes in control were; systolic 171.2 +/- 14.1 to 162.1 +/- 19.5 mmHg and diastolic pressure 97.2 +/- 10.8 to 91.7 +/- 9.7 mmHg. The mean differences in reductions between treated and control were 8.8 mmHg Systolic (95% confidence intervals: -2.6 to 21.2 mmHg) and 7.0 mmHg diastolic blood pressure (95% confidence intervals: 0.4 to 14.4 mmHg). The number of patients with normal blood pressure in the diet treated group at three months was double that in the control (eleven versus five). No relationships were shown between blood pressure changes and those of weight or urinary sodium excretion during the trial. The findings in this study are broadly in agreement with similar ones in essential hypertension and suggest that this form of dietary regimen has a clinically worthwhile hypotensive effect and this should be readily achievable in routine clinical practice.     

The placebo effect and white coat effect in isolated systolic hypertension and systo-diastolic hypertension

It is well recognised from many clinical trials that there is a blood pressure lowering effect when placebo is administered to patients with essential hypertension ("placebo effect"). The reduction in blood pressure, however, may also be partly due to loss of the alerting response ("white coat effect") as a result of familiarisation with the clinical environment. To investigate the hypothesis that there may be a more marked placebo effect and white coat effect in isolated systolic hypertension (ISH) compared with systo-diastolic hypertension (SDH), we studied 78 patients with hypertension: 34 had ISH and 44 patients had SDH. The 34 patients with ISH were older (68.7 vs 54.9 years), had a higher SBP (192.2 vs 169.6 mmHfg) and lower DBP (85.5 vs 102.0 mmHg) when compared to patients with SDH. Amongst the patients with ISH, there were no significant changes in mean blood pressures pre-placebo (paired t-test, p = NS). In the placebo period, there was a significant reduction in systolic blood pressures at all three points, and a significant reduction in diastolic blood pressures after 2 and 3 months placebo (paired t-test, p < 0.05). There was a mean reduction in mean systolic blood pressure at visit 1 by 5.2%, visit 2 by 5.1% and visit 3 by 4.6%, when compared to mean pre-placebo systolic blood pressures (p < 0.05). The mean reduction in diastolic blood pressure was 5.8% at visit 2 and 3.5% at visit 3, when compared to mean pre-placebo diastolic blood pressure (p < 0.05). At the 4-week visit after receiving placebo, the mean systolic blood pressure decreased by 9.4 mmHg (p = 0.003) and mean diastolic blood pressure by 2.7 mmHg (p = NS) in the patients with ISH. In patients with SDH, there were no statistically significant changes in recorded BP readings following the introduction of placebo. We suggest blood pressures in some patients with ISH may settle with careful follow up and initiation of treatment in these patients could potentially be delayed for at least 3 months, as therapy may not prove necessary.     

Effect of a high carbohydrate, low sodium and low fat diet in type 2 diabetics with moderate hypertension

The effect of an intended diet, high in cereal fibre, low in fat and sodium was assessed over a 3-month period in 13 type 2 diabetic patients with moderate hypertension (diastolic blood pressure greater than 105 and less than 115 mmHg without antihypertension drug therapy). Eleven patients completed the study and two patients were withdrawn owing to an increase of blood pressure above initial values after 1 month. Using a compliance scoring system by an observer unaware of blood pressure response, patients were divided into those compliant to the dietary regimen (n = 7; group A) and those who were not, and therefore were considered controls (n = 4; group B). Group A demonstrated significant reductions in systolic (190.4 +/- 18 to 166.6 +/- 22.4 mmHg; P less than 0.02) and diastolic blood pressure (113.1 +/- 3.7 to 103.3 +/- 9.1 mmHg; P less than 0.01), weight (78.5 +/- 5.6 to 74.3 +/- 6.8 kg; P less than 0.02), daily urinary sodium excretion (210.3 +/- 79.9 to 120.3 +/- 56.1 mmol; P less than 0.02) and serum LDL levels (P less than 0.02). A reduction in glycosylated haemoglobin of 2.2 per cent was also noted. Three patients achieved a diastolic blood pressure level below 100 mmHg. In contrast, no significant changes occurred in group B. In particular, systolic and diastolic blood pressure (111.0 +/- 2.2 to 110.3 +/- 8.9 mmHg) remained unchanged. We conclude that the modified diet may have a hypotensive effect in diabetic subjects with moderate hypertension. However, the degree of blood pressure reduction suggests that this diet could, at best, only be considered an adjunct to conventional antihypertensive drug therapy.     

The dietary approaches to stop hypertension (DASH) clinical trial: implications for lifestyle modifications in the treatment of hypertensive patients

Lifestyle modifications, such as weight loss, sodium restriction, and limiting alcohol consumption, are important components of the initial treatment of hypertensive patients. The Dietary Approaches to Stop Hypertension (DASH) study investigated the effects of dietary patterns on blood pressure in individuals with diastolic blood pressure between 80-95 mmHg. Two different dietary patterns were tested in this feeding study. A diet enriched in fruits and vegetables and a diet enriched in fruits, vegetables, and low-fat dairy products and low in total and saturated fat (combination diet) were compared with a control diet. Dietary intake was adjusted so that participants did not lose weight, and all study diets had comparable sodium intake (approximately 3 grams/day). All meals were provided for 459 participants for an 11-week period. Those randomized to the combination diet (n = 151) had a significant change in systolic (-5.5 mmHg; p < 0.001) and diastolic blood pressure (-3.0 mmHg; p < 0.001) after subtracting the response to the control diet (n = 154). The fruits-and-vegetables diet (n = 154) produced a significant but lesser decrease in blood pressure (systolic, -2.8 mmHg; p < 0.001 and diastolic, -1.1 mmHg; p = 0.07). Hypertensive individuals and African Americans had particularly favorable responses with blood pressure reductions, which were significantly greater than other subgroups. The combination diet was well-accepted and adherence to the diet was high (>90%) for all participants. The DASH combination diet is an effective lifestyle modification for lowering blood pressure in patients with high-normal or Stage 1 hypertension.     

Behavioural hypertension in sodium-loaded dogs is accompanied by sustained sodium retention

Instrumented dogs were presented with two daily avoidance conditioning sessions during 12 days of continuous saline infusion (1.3 l/day). Avoidance conditioning of sodium-loaded dogs resulted in progressive 24-h hypertension over the 12-day conditioning periods (systolic, 21 +/- 3 mmHg; diastolic, 15 +/- 1 mmHg) accompanied by a decreased 24-h heart rate (-14.8 +/- 4.0 beats/min). Under these conditions, renal excretion of sodium decreased relative to sodium intake (-88 +/- 19 mmol/12 days) while urine volume was increased relative to water intake (0.18 +/- 0.07 l/day). The sodium retention was accompanied by increased plasma sodium levels (1.8 +/- 0.7 mmol/l) and decreased plasma calcium levels (-1.2 +/- 0.2 mmol/l). Daily creatinine clearance decreased during the development of hypertension (-53 +/- 13% per day). Subsequently, each dog was exposed to 12 days of saline infusion in the absence of avoidance sessions. Under these conditions, arterial pressure and sodium balance remained stable. It was concluded that the rapidly developing and reversible hypertension occurring in sodium-loaded dogs exposed to recurrent behavioural stress is mediated by increased levels of total body sodium.     

Nifedipine and arotinolol in combination for accelerated-malignant hypertension: results of one year follow-up.

The effects of a combined therapy with a calcium channel antagonist and alphabeta-blocker in patients with accelerated-malignant hypertension on blood pressure and renal function were examined. Thirteen patients presented with the clinical features of malignant hypertension (diastolic blood pressure >130 mmHg, retinal damage and progressive renal failure) at our hospital, over the 3 yr period from 1995 to 1997. These patients were treated with both a calcium antagonist, 60-80 mg/d dose of long acting nifedipine, and an alphabeta-blocker, 20 mg/d dose of arotinolol, for over 12 mo. At admission, the average blood pressure of the patients was 233+/-8/144+/-3 mmHg. The level of serum creatinine in these patients was 6.2+/-1.0 mg/dl. Intermittent hemodialysis therapy was introduced in 7 patients. Three days after treatment, blood pressure decreased to 162+/-4/102+/-4 mmHg. A month later, blood pressure decreased to 148+/-3/89+/-2 mmHg and serum creatinine levels were 3.6+/-0.4 mg/dl. Renal function in these patients improved, and they completely recovered from renal dysfunction, allowing withdrawal of haemodialysis therapy. One year later, the blood pressure in all of these patients was well controlled and no further renal deterioration was observed, except in one patient. Despite the reduction in blood pressure, one patient was on hemodialysis three times a week after 8 mo of treatment. From these finding, it is concluded that combination therapy with a calcium antagonist and alphabeta-blocker is effective in both the reduction of highly elevated blood pressure and protection of the kidneys, resulting in amelioration of accelerated-malignant hypertension.     

Measurements of blood pressure with various techniques in daily practice: uncertainty in diagnosing office hypertension with short-term in-hospital registration of blood pressure.

OBJECTIVE: To predict blood pressure outside the clinic from a short-term in-hospital registration for patients referred for ambulatory blood pressure monitoring (ABPM) with special attention to office hypertension. PATIENTS AND METHODS: A series of measurements of blood pressure was performed by the same technician for 187 patients, 82% of whom were being administered antihypertensive therapy. She performed three mercury measurements of blood pressure (Hg stress 1) and then three manually started measurements with a semi-automatic device (Dinamap 1846SX; Dinamap stress) alternated with three manually started readings with a SpaceLabs 90207 monitor (SpaceLabs stress) on the contralateral non-dominant arm. The in-hospital session was continued with 15 automatic Dinamap registrations at 2 min intervals without the technician being present (Dinamap unstressed, five periods of three measurements averaged) before the patient left the hospital for 24h ABPM. RESULTS: The percentages of patients with hypertension in the office (systolic blood pressure >/= 140 mmHg or diastolic blood pressure >/= 90 mmHg, or both) were 80% with Hg stress 1, 76% with Dinamap stress and 85.0% with SpaceLabs stress. Average diastolic SpaceLabs stress was 6.0+/-5.6 mmHg (significantly) higher than diastolic Dinamap stress, whereas the difference between systolic blood pressures was 0.2+/-10.0 mmHg. No further change in blood pressure occurred after the fourth period of Dinamap unstressed measurements. Office hypertension defined as SpaceLabs stress systolic blood pressure >/= 140 mmHg or diastolic blood pressure >/= 90 mmHg, or both, and SpaceLabs daytime systolic blood pressure < 135 mmHg and diastolic blood pressure < 85 mmHg was found in 21 individuals. Office hypertension defined with similar cut-off points in the comparison of Dinamap stress versus Dinamap unstressed period 5 was found in 29 cases, 10 of which overlapped with the definition SpaceLabs stress versus SpaceLabs daytime. The differences between Dinamap stress and Dinamap unstressed period 5 were significantly correlated to the changes of SpaceLabs stress and SpaceLabs daytime both for systolic (r =0.41) and for diastolic (r =0.32) blood pressures. CONCLUSIONS: Measurements of blood pressure in the office with various techniques (mercury, Dinamap and SpaceLabs) are not equivalent. Office hypertension cannot be reliably predicted from a short-term semi-automatic in-hospital registration of blood pressure with a Dinamap device.     

Arterial hypertension and the right heart. A hemodynamic and echocardiographic study]

OBJECTIVE: To evaluate the effects of arterial hypertension on the pulmonary circulation and the right heart. SETTING: Coronary Care Unit (UTIC Arsénio Cordeiro) Hemodynamics Laboratory and Medicine I Echocardiography Laboratory-Santa Maria Hospital. PARTICIPANTS: 38 hypertensive patients separated in two groups: 24 with thickened septum and left ventricular posterior wall (10 with hemodynamic evaluation)--Group A--and 14 without thickening--Group B; a control group of 12 healthy volunteers--Group C. RESULTS: The hypertensive patients with hemodynamic evaluation had normal pulmonary capillary wedge pressure the average pulmonary resistance (135.29 +/- 63.47 dyn.cm.5), pulmonary systolic (31.30 +/- 10.01 mmHg) and mean pressures (18.23 +/- 8.21 mmHg) were raised, but the diastolic pulmonary pressure was normal. The right ventricle systolic pressure was raised (32.10 +/- 9.12 mmHg) and there was no modification of the right atrial or ventricular telediastolic pressures. On echocardiography there was a diastolic thickening of the right ventricular free wall in both group A (7.08 +/- 1.41 mm) and B (4.07 +/- 1.00 mm) as compared to group C (3.08 +/- 0.51 mm); there were similar findings regarding systolic thickness with statistical significance in group A (p less than 0.001). The right ventricular ejection fraction was normal in both groups. There was a positive correlation between the diastolic thickness of left ventricular posterior wall and right ventricular free wall in hypertensive patients and normotensive volunteers (r = 0.7754; p less than 0.001). CONCLUSIONS: The findings suggest an anatomic an functional relationship between both ventricles regarding the cardiac repercussions of arterial hypertension.     

Effects of Sodium Concentration and Dialysate Temperature Changes on Blood Pressure in Hemodialysis Patients: A Randomized,Triple‐Blind Crossover Clinical Trial

The present study investigated the effects of different temperatures and sodium dialysate concentration on blood pressure in hemodialysis patients. Following Williams’ design, hemodialysis patients were randomly assigned into four dialysis modes. Dialysate temperature was set at 37°C for modes A and C and, 35°C for modes B and D. Sodium concentration was set at 138 mmol/L in modes A and B, while it changed from 150 mmol/L to 138 mmol/L in modes C and D. Using analysis of variance for repeated measures, the mean values of systolic and diastolic blood pressure were investigated. The mean values of systolic and diastolic blood pressure in modes C and D had a significant difference with the values in mode A. The mean values of systolic and diastolic blood pressure in patients dialyzed with mode B had a significant difference with the values in those dialyzed with mode D. Moreover, there were significant differences in the incidence of hypotension between A and other modes and between B and modes C and D, but this difference was not significant between modes C and D. In order to reduce intradialytic blood pressure fluctuations and hypotension, the nursing staff are recommended to gradually reduce dialysate sodium concentration.     

序贯钠透析在预防透析低血压中的应用

目的 :研究序贯钠透析对透析低血压的预防作用。方法 :对连续 4次血透中发生透析低血压≥ 2次的 16例应用序贯钠透析干预共 92次 ,观察血液透析中的血压变化和临床症状的改善情况 ,干预前次透析液钠浓度均为 14 0mmol/L ,序贯钠透析起始钠浓度为 15 0mmol/L ,逐渐降至 138mmol/L。结果 :应用序贯钠透析后 ,透析中最低血压、透析后和透析中的平均收缩压的升高显著 ,大于 10mmHg(P <0 .0 1) ,临床症状几乎完全消失 ,未发现患者有任何不耐受情况。结论 :应用序贯钠透析能够非常有效地预防透析低血压的发生 ,使透析过程更安全