Is race adjustment necessary to estimate glomerular filtration rate in South Brazilians?

Background And Aims: Race coefficients (RC) in equations to estimate glomerular filtration rate (GFR) have been highly questioned. We aimed to evaluate the performance of three equations, namely 2009 Chronic Kidney Disease Epidemiology Collaboration (2009 CKD-EPI), 2021 CKD-EPI, and European Kidney Function Consortium (EKFC) in self-reported Black and White Brazilians.

Materials And Methods: Our cross-sectional study compared estimated GFR (eGFR) with Cr-EDTA measured GFR (mGFR) in healthy adults, patients with type 2 diabetes mellitus with or without chronic kidney disease (CKD), and in non-diabetic individuals with CKD.

Isometric handgrip exercise impacts only on very short-term blood pressure variability, but not on short-term blood pressure variability in hypertensive individuals: A randomized controlled trial.

The effect of a single isometric handgrip exercise (IHG) on blood pressure (BP) variability (BPV) has not been addressed. This randomized controlled trial evaluated the effect of IHG vs. sham on BPV and BP.

Acoustic signal of silent tracheal aspiration in children with oropharyngeal dysphagia.

Unlabelled: Objetive: The aim of this study was to characterize the acoustic signal of silent tracheal aspiration in children with oropharyngeal dysphagia (OPD).

Method: Thirty-two children with OPD were examined with combined digital cervical auscultation (DCA) and videofluoroscopic swallow study (VFSS). Power spectral density (PSD, in 1/√Hz) of the acoustic signal from a sequential series of five liquid swallows was used for comparisons between children who silently aspirated and children who did not aspirate on VFSS.

Cholinesterase inhibition reduces arrhythmias in asymptomatic Chagas disease.

Introduction: Parasympathetic dysfunction may play a role in the genesis of arrhythmias in Chagas disease.

Aim: This study evaluates the acute effects of pyridostigmine (PYR), a reversible cholinesterase inhibitor, on the occurrence of arrhythmias in patients with Chagas cardiac disease.

Method: Following a double-blind, randomized, placebo-controlled, cross-over protocol, 17 patients (age 50±2 years) with Chagas cardiac disease type B underwent 24-hour Holter recordings after oral administration of either pyridostigmine bromide (45 mg, 3 times/day) or placebo (PLA).

Spontaneous breathing trial in T-tube negatively impact on autonomic modulation of heart rate compared with pressure support in critically ill patients.

Introduction: Spontaneous breathing with a conventional T-piece (TT) connected to the tracheal tube orotraqueal has been frequently used in clinical setting to weaning of mechanical ventilation (MV), when compared with pressure support ventilation (PSV). However, the acute effects of spontaneous breathing with TT versus PSV on autonomic function assessed through heart rate variability (HRV) have not been fully elucidated.

Objective: The purpose of this study was to examine the acute effects of spontaneous breathing in TT vs PSV in critically ill patients.

Inspiratory muscle training in type 2 diabetes with inspiratory muscle weakness.

Purpose: Patients with type 2 diabetes mellitus may present weakness of the inspiratory muscles. We tested the hypothesis that inspiratory muscle training (IMT) could improve inspiratory muscle strength, pulmonary function, functional capacity, and autonomic modulation in patients with type 2 diabetes and weakness of the inspiratory muscles.

Methods: Maximal inspiratory muscle pressure (PImax) was evaluated in a sample of 148 patients with type 2 diabetes.

Acute ingestion of alcohol and cardiac autonomic modulation in healthy volunteers.

Arrhythmogenic effects of alcohol may be intermediated by its effects over heart rate variability (HRV). Most studies about the effects of alcohol over HRV were observational and did not explore the temporal influence of alcohol ingestion over autonomic modulation. The aim of this study was to verify if an acute ingestion of alcohol has a time-dependent influence over time-domain indices of HRV.

Association between different measurements of blood pressure variability by ABP monitoring and ankle-brachial index.

Background: Blood pressure (BP) variability has been associated with cardiovascular outcomes, but there is no consensus about the more effective method to measure it by ambulatory blood pressure monitoring (ABPM). We evaluated the association between three different methods to estimate BP variability by ABPM and the ankle brachial index (ABI).

Methods And Results: In a cross-sectional study of patients with hypertension, BP variability was estimated by the time rate index (the first derivative of SBP over time), standard deviation (SD) of 24-hour SBP; and coefficient of variability of 24-hour SBP.

Effects of altering pedal frequency on the slow component of pulmonary VO2 kinetics and EMG activity.

This study investigated the effects of pedal frequency on the slow component of pulmonary oxygen uptake ( V O(2)) kinetics during heavy exercise at the same relative intensity. We hypothesized that higher pedal frequency (expected to enhance fast-twitch muscle fiber recruitment) would be associated with greater slow component amplitude (A' (s)), surface electromyography (normalized root mean square; RMS) and blood lactate concentration ([lactate]). Eight subjects performed square-wave transitions to heavy exercise at 35 and 115 rpm.

Assessment of swallowing sounds by digital cervical auscultation in children.

Objectives: There is a lack of studies regarding swallowing sounds in children 3 to 11 years of age. This study aimed to assess swallowing sounds by digital cervical auscultation in children of this age group without symptoms of oropharyngeal dysphagia.

Methods: Digital cervical auscultation was performed in 118 subjects by use of a piezoelectric microphone.

Inspiratory muscle training improves blood flow to resting and exercising limbs in patients with chronic heart failure.

Objectives: We tested the hypothesis that inspiratory muscle loading could result in exaggerated peripheral vasoconstriction in resting and exercising limbs and that inspiratory muscle training (IMT) could attenuate this effect in patients with chronic heart failure (CHF) and inspiratory muscle weakness.

Background: Inspiratory muscle training improves functional capacity of patients with CHF, but the mechanisms of this effect are unknown.

Methods: Eighteen patients with CHF and inspiratory muscle weakness (maximal inspiratory pressure <70% of predicted) and 10 healthy volunteers participated in the study.

Blood lactate during recovery from intense exercise: impact of inspiratory loading.

Purpose: It has long been suggested that inspiratory muscle activity may impact blood lactate levels ([Lac(-)]B) during the recovery from dynamic exercise. In this study, we tested the hypothesis that inspiratory muscle activation during recovery from intense exercise would contribute to La clearance, thus leading to reduced [Lac(-)]B.

Methods: Twelve healthy men underwent two maximal, incremental exercise tests on different days.

Detection of arteriolar narrowing in fundoscopic examination: evidence of a low performance of direct ophthalmoscopy in comparison with a microdensitometric method.

Background: Retinal abnormalities, particularly arteriolar narrowing, are powerful predictors of cardiovascular events. The precision of internists and ophthalmologists in the assessment of retinal vessels widths has been disputed but not evaluated against a technology of edge detection.

Methods: Fifty-two patients with hypertension had optic fundi examination done by an internist and an ophthalmologist, and had retinographies taken and digitized to determine vessel diameters by a new technology of edge detection (microdensitometric method).

Acute water ingestion increases arterial blood pressure in hypertensive and normotensive subjects.

In patients with severe autonomic dysfunction, water ingestion elicits an acute pressor response. Hypertension may be associated with changes in cardiovascular autonomic modulation, but there is no information on the acute effects of water ingestion in patients with hypertension. In this study, we compared the effect of acute water ingestion on haemodynamic and autonomic responses of hypertensive and normotensive individuals.

Measuring arteriolar-to-venous ratio in retinal photography of patients with hypertension: development and application of a new semi-automated method.

Background: The extent of arteriolar narrowing has been recognized as a major sign of end-organ damage in patients with hypertension, but most methods used for its evaluation are highly dependent on the observer. We describe a new semi-automated method to measuring arteriolar-to-venous (A/V) ratio in retinal photography and present its application in the evaluation of patients with hypertension.

Methods: In a cross-sectional study, 58 patients with hypertension had retinographies taken and digitized to determine the vessel diameter by direct measurement (micrometric method) or by the new microdensitometric method.

Hormone replacement therapy does not affect the 24-hour heart rate variability in postmenopausal women: results of a randomized, placebo-controlled trial with two regimens.

Postmenopausal women are at greater risk of coronary heart disease. The results of previous studies of the effects of hormone replacement therapy (HRT) on cardiac autonomic modulation in postmenopausal women have been contradictory. This study examined whether continuous treatment for 3 months with estradiol alone (ERT) or with estradiol plus norethisterone (HRT), increases 24-hour heart rate variability (HRV) in postmenopausal women.

Relationship between cardiovascular dysfunction and hyperglycemia in streptozotocin-induced diabetes in rats.

Streptozotocin (STZ)-induced diabetes in rats is characterized by cardiovascular dysfunction beginning 5 days after STZ injection, which may reflect functional or structural autonomic nervous system damage. We investigated cardiovascular and autonomic function, in rats weighing 166 +/- 4 g, 5-7, 14, 30, 45, and 90 days after STZ injection (N = 24, 33, 27, 14, and 13, respectively). Arterial pressure (AP), mean AP (MAP) variability (standard deviation of the mean of MAP, SDMMAP), heart rate (HR), HR variability (standard deviation of the normal pulse intervals, SDNN), and root mean square of successive difference of pulse intervals (RMSSD) were measured.

Cholinergic stimulation with pyridostigmine reduces ventricular arrhythmia and enhances heart rate variability in heart failure.

Background: Increased ventricular arrhythmia density and reduced heart rate variability are associated with risk of death in patients with heart failure. Cholinesterase inhibition with pyridostigmine bromide increases heart rate variability in normal subjects, but its effect on patients with heart failure is unknown. In this study, we tested the hypothesis that short-term administration of pyridostigmine bromide, a cholinesterase inhibitor, reduces ventricular arrhythmia density and increases heart rate variability in patients with congestive heart failure.

Contribution of nitric oxide to arterial pressure and heart rate variability in rats submitted to high-sodium intake.

The aim of this study was to determine the contribution of NO to arterial pressure and heart rate variability in normotensive rats subjected to high sodium intake. Arterial pressure, heart rate, and arterial pressure and heart rate variability, baroreflex sensitivity, and pressure responsiveness were measured in male Wistar rats treated for 6 weeks (control and high sodium [1%] intake groups), before and after acute NO synthesis blockade. After treatment, no changes were observed in arterial pressure or heart rate.

Enhancement of heart rate variability by cholinergic stimulation with pyridostigmine in healthy subjects.

The purpose of this study was to determine the effect of the oral administration of pyridostigmine bromide on indices of heart rate variability (HRV) in healthy young volunteers. Seventeen healthy participants (11 men, 6 women; aged 27 +/- 8 y) submitted to a randomized, crossover, double-blind protocol, in which they received 30 mg pyridostigmine bromide (PYR) or placebo orally at 8-hour intervals for 24 hours, on two separate days. Venous blood samples were collected 2 and 24 hours after the first dose for determination of serum cholinesterase activity.

Parasympathetic dysautonomia precedes left ventricular systolic dysfunction in Chagas disease.

Background: Parasympathetic dysautonomia is an established feature of advanced Chagas cardiomyopathy. However, in the absence of cardiac involvement, the presence of vagal dysfunction remains controversial. In a cross-sectional study, we compared patients with Chagas disease without cardiac involvement and healthy individuals by three different methods to determine whether vagal dysfunction is present in the early phase of Chagas disease.

Three-dimensional return map: a new tool for quantification of heart rate variability.

Background: Several methods are used to study heart rate variability, but they have limitations, which might be overcome by the use of a three-dimensional return map.

Objectives: To evaluate the performance of three-dimensional return map-derived indices to detect (1) sympathetic and parasympathetic modulation to the sinus node and (2) autonomic dysfunction in diabetic patients.

Methods: Six healthy subjects underwent partial and total pharmacological autonomic blockade in a protocol that incorporated vagal and sympathetic predominance.

Autonomic dysfunction and urinary albumin excretion rate are associated with an abnormal blood pressure pattern in normotensive normoalbuminuric type 1 diabetic patients.

Objective: To analyze the role of autonomic function and other possible factors associated with a blunted fall in nocturnal blood pressure.

Research Design And Methods: A total of 39 normotensive normnoalbuminuric type 1 diabetic patients were studied. Glomerular filtration rate (51Cr-EDTA technique), extracellular volume (51Cr-EDTA distribution volume), and urinary albumin excretion rate (UAER) (by radioimmunoassay) were measured.