Giovanio Vieira da Silva

Home blood pressure monitoring in blood pressure control among haemodialysis patients: an open randomized clinical trial

BACKGROUND It is not known if the adjustment of antihypertensive therapy based on home blood pressure monitoring (HBPM) can improve blood pressure (BP) control among haemodialysis patients. METHODS This is an open randomized clinical trial. Hypertensive patients on haemodialysis were randomized to have the antihypertensive therapy adjusted based on predialysis BP measurements or HBPM. Before and after 6 months of follow-up, patients were submitted to ambulatory blood pressure monitoring (ABPM) for 24 h, HBPM during 1 week and echocardiogram. RESULTS A total of 34 and 31 patients completed the study in the HBPM and predialysis BP groups, respectively. At the end of study, the systolic (SBP) and diastolic (DBP) blood pressure during the interdialytic period measured by ABPM were significantly lower in the HBPM group in relation to the predialysis BP group (mean 24-h BP: 135 +/- 12 mmHg/76 +/- 7 mmHg versus 147 +/- 15 mmHg/79 +/- 8 mmHg; P < 0.05). In the HBPM analysis, the HBPM group showed a significant reduction only in SBP compared to the predialysis BP group (weekly mean: 144 +/- 21 mmHg versus 154 +/- 22 mmHg; P < 0.05). There were no differences between the HBPM and predialysis BP groups in relation to the left ventricular mass index at the end of the study (108 +/- 35 g/m(2) versus 110 +/- 33 g/m(2); P > 0.05). CONCLUSIONS Decision making based on HBPM among haemodialysis patients has led to a better BP control during the interdialytic period in comparison with predialysis BP measurements. HBPM may be a useful adjuvant instrument for blood pressure control among haemodialysis patients.

Intra-Arterial Blood Pressure Response in Hypertensive Subjects during Low- and High-Intensity Resistance Exercise

OBJECTIVE: The aim of this study was to describe blood pressure responses during resistance exercise in hypertensive subjects and to determine whether an exercise protocol alters these responses. INTRODUCTION: Resistance exercise has been recommended as a complement for aerobic exercise for hypertensive patients. However, blood pressure changes during this kind of exercise have been poorly investigated in hypertensives, despite multiple studies of normotensives demonstrating significant increases in blood pressure. METHODS: Ten hypertensive and ten normotensive subjects performed, in random order, two different exercise protocols, composed by three sets of the knee extension exercise conducted to exhaustion: 40% of the 1-repetition maximum (1RM) with a 45-s rest between sets, and 80% of 1RM with a 90-s rest between sets. Radial intra-arterial blood pressure was measured before and throughout each protocol. RESULTS: Compared with normotensives, hypertensives displayed greater increases in systolic BP during exercise at 80% (+80±3 vs. +62±2 mmHg, P<0.05) and at 40% of 1RM (+75±3 vs. +67±3 mmHg, P<0.05). In both exercise protocols, systolic blood pressure returned to baseline during the rest periods between sets in the normotensives; however, in the hypertensives, BP remained slightly elevated at 40% of 1RM. During rest periods, diastolic blood pressure returned to baseline in hypertensives and dropped below baseline in normotensives. CONCLUSION: Resistance exercise increased systolic blood pressure considerably more in hypertensives than in normotensives, and this increase was greater when lower-intensity exercise was performed to the point of exhaustion.

Home blood pressure (BP) monitoring in kidney transplant recipients is more adequate to monitor BP than office BP

BACKGROUND Hypertension is highly prevalent among kidney transplantation recipients and considered as an important cardiovascular risk factor influencing patient survival and kidney graft survival. Aim. Compare the blood pressure (BP) control in kidney transplant patients through the use of home blood pressure monitoring (HBPM) is more comparable with the results of ambulatory blood pressure monitoring compared to the measurement of office blood pressure. METHODS From March 2008 to April 2009 prospectively were evaluated 183 kidney transplant recipients with time after transplantation between 1 and 10 years. Patients underwent three methods for measuring BP: office blood pressure measurement (oBP), HBPM and ambulatory blood pressure monitoring (ABPM). RESULTS In total, 183 patients were evaluated, among them 94 were men (54%) and 89 women (46%). The average age was 50 ± 11 years. The average time of transplant was 57 ± 32 months. Ninety-nine patients received grafts from deceased donors (54%) and 84 were recipients of living donors (46%). When assessed using oBP, 56.3% presented with uncontrolled and 43.7% with adequate control of BP with an average of 138.9/82.3 ± 17.8/12.1 mmHg. However, when measured by HBPM, 55.2% of subjects were controlled and 44.8% presented with uncontrolled BP with an average of 131.1/78.5 ± 17.4/8.9 mmHg. Using the ABPM, we observed that 63.9% of subjects were controlled and 36.1% of patients presented uncontrolled BP with an average 128.8/80.5 ± 12.5/8.1 mmHg. We found that the two methods (oBP and HBPM) have a significant agreement, but the HBPM has a higher agreement that oBP, confirmed P = 0.026. We found that there is no symmetry in the data for both methods with McNemar test. The correlation index of Pearson linear methods for the ABPM with the other two methods were 0.494 for office measurement and 0.768 for HBPM, best value of HBPM with ABPM. Comparing the errors of the two methods by paired t-test, we obtained the descriptive level of 0.837. Looking at the receiver operating characteristic curve for BP measurements in each method, we observed that oBP is lower than those obtained by HBPM in relation to ABPM. CONCLUSION We conclude that the results obtained with HBPM were closer to the ABPM results than those obtained with BP obtained at oBP, being more sensitive to detect poor control of hypertension in renal transplant recipients.

Os médicos brasileiros seguem as diretrizes brasileiras de hipertensão

OBJECTIVE To evaluate whether procedures adopted by Brazilian physicians in the diagnosis and treatment of hypertension are in compliance with those advocated by the IV Brazilian Hypertension Guidelines. METHOD Survey carried out by means of telephone interviews with Brazilian physicians. The survey featured application of a questionnaire aimed to assess receipt of and compliance with the guidelines, and to evaluate various aspects regarding the treatment of hypertensive patients. RESULTS 68.3% of the respondents had received the guidelines and answered the questionnaire in full. The total sample consisted of 483 physicians--47% cardiologists, 31.7% internists, and 21.3% nephrologists. The survey showed high compliance with certain guideline topics such as more than one measurement at different times for the diagnosis of hypertension (94%), and providing guidance regarding lifestyle changes as a therapeutic strategy. As to arterial pressure levels used for diagnosis and therapeutic target, compliance with guideline recommendations lacks uniformity. The survey showed a clear preference for pressure levels lower than those recommended, especially in patients with comorbidities. Attempts to assess cardiovascular risk also proved to be low. Only 64.7% of the respondents reported that they seek to determine the presence of diabetes mellitus, and 56.4% check for dyslipidemia. The majority (59.3%) mentioned diuretics as the preferred drug class for initial drug treatment of hypertension. CONCLUSION We concluded that there is only partial compliance with Brazilian Hypertension Guidelines and that certain factors should be taken into consideration when drawing up future guidelines, such as: improved distribution; standardization of values for diagnosis and therapeutic target; more extensive coverage of ways for physicians to approach hypertensive patients to better evaluate their overall cardiovascular risk.

Metaboreflex activation delays heart rate recovery after aerobic exercise in never-treated hypertensive men

Recent evidence indicates that metaboreflex regulates heart rate recovery after exercise (HRR). An increased metaboreflex activity during the post‐exercise period might help to explain the reduced HRR observed in hypertensive subjects. Using lower limb circulatory occlusion, the present study showed that metaboreflex activation during the post‐exercise period delayed HRR in never‐treated hypertensive men compared to normotensives. These findings may be relevant for understanding the physiological mechanisms associated with autonomic dysfunction in hypertensive men.

Prevalence and factors associated with chronic kidney disease among hospitalized patients in a university hospital in the city of São Paulo, SP, Brazil

INTRODUCTION Chronic kidney disease (CKD) is a major public health problem worldwide. Nonetheless, little is known about its features in Brazil. OBJECTIVE To identify prevalence and factors associated with CKD among hospitalized patients in a university hospital. METHODS We randomly selected 826 medical records of patients admitted in 2009 in the medical inpatient unit. We defined CKD as the presence of medical diagnosis or personal history. We collected a number of clinical and demographic information and these variables were compared between patients with and without CKD. RESULTS CKD prevalence was 12.7%. Patients with CKD differed from patients without (p < 0.05) regarding to: living with a partner (59.8% vs. 47.3%), older age (65.8 ± 15.6 vs. 55.3 ± 18.9 years-old), more comorbidities as hypertension (75.2% vs. 46.3%), diabetes (49.5% vs. 22.4%), dyslipidemia (23.8% vs. 14.9%), acute myocardial infarction (14.3% vs. 6.0%) and congestive heart failure (18.1% vs. 4.3%); length of hospitalization (11 (8-18) vs. 9 (6-12) days); and death occurrence (12.4% vs. 1.4%). The logistic regression analysis showed an independent association (OR, odds ratio, CI, confidence interval 95%) of CKD with age (OR 1.019, CI 1.003 to 1.036), hypertension (OR 2.032, CI 1.128 to 3.660), diabetes (OR 2.097, CI 1.232 to 3.570) and congestive heart failure (OR 2.665, CI 1.173 to 6.056). CONCLUSION CKD prevalence among patients in a medical inpatient unit was high and CKD patients were more complex, as they were older and had a great number of co-morbidities, reflecting a greater risk of death during hospitalization.

Reduction of sympathetic nervous activity with device-guided breathing.

To the Editor: Hypertension is a chronic disease that affects about 25% of the population around the world. Treatment by pharmacologic intervention is effective but has side effects and significant costs. Techniques that reduce respiratory rate have been shown to be an effective nonpharmacologic treatment in controlling blood pressure (BP). Evidence has shown that a slow and deep breathing rate, around 10 breaths or less per minute, significantly reduces BP. The physiological mechanisms involved in reduction of BP caused by decreased respiratory rate, however, are not yet known. In this report, we show an expressive reduction of sympathetic nervous activity with regular use of device-guided breathing. A white 52-year-old male nurse presented with elevated BP in casual measurement (systolic BP between 140 mm Hg and 150 mm Hg and diastolic BP between 90 mm Hg and 100 mm Hg) for about 1 year. The patient denied other chronic diseases or use of continuous prescription medications, including antihypertensive agents. He reported having a father and a sister with hypertension. He denied smoking or abusive consumption of alcohol and practices resistance exercise 3 times a week. On physical examination, he presented with body mass index of 28.1 kg/m and BP 134/91 mm Hg (mean of 2 measurements). There were no other alterations in the physical examination. Ambulatory blood pressure monitoring (ABPM) performed with the Mobil-O-Graph (I.E.M., Solberg, Germany) device, validated according to the British Hypertension Society protocol, showed elevation in the mean values of diastolic BP over 24 hours (131/ 92 mm Hg), awake (139/100 mm Hg), and at sleep (113/75 mm Hg). Ancillary tests showed normal renal function (creatinine: 0.76 mg/dL), normokalemia (K: 4.4 mEq/L), sinus rhythm on electrocardiography, and no evidence of left ventricular hypertrophy. With a diagnosis of primary arterial hypertension, the patient was introduced to nonpharmacologic treatment by means of device-guided breathing, an alternative he readily accepted. Briefly, the equipment initiallymonitors the individual’s breathing and then personalizes amelody composed of two different tones, one for inspiration and the other expiration. The patient synchronizes respiration with the melody proposed by the equipment, which gradually prolongs the tone of expiration, inducing the individual to breathe more slowly. The patient received training on how to use the equipment (Resperate, Intercure, Israel) and was instructed to perform daily 15-minute sessions with the objective of decreasing breathing rate to <10 respiratory incursions per minute during 8 weeks. At the beginning and after the period of 8 weeks of treatment, blood samples were collected to measure plasma catecholamines by using the highperformance liquid chromatography technique, and peripheral sympathetic nervous activity was measured by the microneurography technique that enables registration of action potentials of sympathetic fibers A and C in peripheral nerves. The technique consists, initially, of an electrical percutaneous stimulation (40 V–120 V) to map the trajectory of the fibular nerve. Posteriorly, a tungstenmicroelectrode (30–40 mm in length) is inserted into the nerve, at the site of best response to the percutaneous stimulation, with internal stimulation of 4 V to 5 Vuntil a location is obtainedwhere this stimulus triggers involuntary contraction of the leg muscle, without paresthesia. The nervous signal was recorded during 20 minutes on a microcomputer by the LabChart 7 Pro program (ADInstruments, Dunedin, New Zealand) at a sample frequency of 2 K/s. Sympathetic nervous activity was measured by counting the number of nervous impulses per minute. The patient showed good compliance with the guided breathing exercise: memory of the equipment showed use of the device on 100% of the days during the time recommended,with a finalmean of respiratory incursions of 6.9 breathing movements per minute. There was a discreet reduction in office BP (122/88 mmHg) and in the mean values of 24-hour (127/89 mm Hg) and awake (132/97 mm Hg) ABPM, but not during sleep (117/ 76 mm Hg). For the measurement of sympathetic nervous activity, there was a significant decrease in the values of noradrenalin before and after the treatment period (903 pg/mL vs 220 pg/mL), as well as of peripheral sympathetic nervous activity measured by microneurography (51 bursts per minute vs 22 bursts per minute) (Figure). Reduction of BP with the regular use of device-guided breathing is well documented in a series of clinical studies, and it is also recommended as an alternative to drug treatment in a recent guideline of the American Heart Association. Nevertheless, the mechanisms through which the reduction of respiratory frequency brings down BP need to be better understood. One of the hypotheses raised would be the reduction of nervous sympathetic activity: reductions in respiratory frequency of about 6 to 10 breaths per minute, as they increase tidal volume, would stimulate cardiopulmonary stretch receptors, which conversely would reduce the discharge of efferent sympathetic fibers, resulting in decreased systemic vascular resistance and consequent reduction of arterial pressure. However, such a hypothesis has not yet been fully confirmed in hypertensive patients who regularly perform this type of intervention. Support: FAPESP 2010/06921-2

Effects of long term device-guided slow breathing on sympathetic nervous activity in hypertensive patients: a randomized open-label clinical trial

Abstract Purpose: Device-guided slow breathing (DGB) is indicated as nonpharmacological treatment for hypertension. The sympathetic nerve activity (SNA) reduction may be one of the mechanisms involved in blood pressure (BP) decrease. The aim of this study is to evaluate the long-term use of DGB in BP and SNA. Subjects and methods: Hypertensive patients were randomized to listen music (Control Group–CG) or DGB (aim to reduce respiratory rate to less than 10 breaths/minute during 15 minutes/day for 8 weeks). Before and after intervention ambulatory blood pressure monitoring (ABPM), catecholamines and muscle sympathetic nerve activity (MSNA) by microneurography were performed. Results: 17 volunteers in the DGB and 15 in the CG completed the study. There was no change in office BP before and after intervention in both groups. There was a reduction in systolic and diastolic BP in the awake period by ABPM only in the CG (131 ± 10/92 ± 9 vs 128 ± 10/88 ± 8mmHg, p < 0.05). In relation to SNA, no difference in catecholamines was observed. In the volunteers who had a microneurography record, there was no change the MSNA (bursts/minute): DGB (17(15–28) vs 19(13–22), p = 0.08) and CG (22(17–23) vs 22(18–24), p = 0.52). Conclusion: Long-term DGB did not reduce BP, catecholamines levels or MSNA in hypertensive patients. ClinicalTrials.gov identifier: NCT01390727

Nocturnal Blood Pressure Fall Changes in Correlation With Urinary Sodium Excretion

To the Editor: In the April 2008 issue of Hypertension , Bankir et al1 analyzed the data of 325 subjects divided into tertiles of the day:night ratio of urinary sodium excretion. Subjects in tertile 3 were qualified as “high daytime sodium excretors” because they excreted sodium at a rate that was 46% higher during daytime than during nighttime, whereas subjects in tertile 1 were “low daytime sodium excretors” and excreted 3 times less sodium during daytime than during nighttime. The nocturnal blood pressure (BP) dipping was significantly lower in tertile …

Qual a diretriz de hipertensão arterial os médicos brasileiros devem seguir? Análise comparativa das diretrizes brasileiras, européias e norte-americanas (JNC VII)

Hospital das Clinicas da FMUSP e Comissao Permanente das IV DiretrizesBrasileiras de Hipertensao ArterialEndereco para Correspondencia: Decio Mion Junior - Av. Dr. Eneas deCarvalho Aguiar, 255 - Inst. Central do HC - 7o andar, s/ 7032Cep 05403-000 - Sao Paulo - SP - E-mail: deciomion@uol.com.brRecebido para Pulbicacao em 02/12/2003Aceito em 9/03/2004