Sustained Handgrip Research Articles

Assessment of Cardiac Autonomic Functions in Medical Students With Type D Personality.

Type D personality experiences joint occurrence of Negative Affectivity and Social Inhibition. It is an emerging risk factor for cardiovascular disease, with prevalence being 18-53% among cardiac patients. Type D personality people have exaggerated cardiovascular activity mediated by increased sympathetic drive and decreased vagal control of the heart which leads to enhanced risk of hypertension and is an independent risk factor for coronary heart disease. To compare the cardiac autonomic function of Type D and non-Type D students. To compare cardiac autonomic functions among male and female students and students with and without family history of hypertension and coronary artery disease among Type D. To find the most affected test among Type D students. Thirty Type D and 30 non- Type D medical students were identified by DS14. The Parasympathetic cardiac autonomic tests done assessed Heart Rate response to valsalva manoeuvre, immediate heart rate response to standing and heart rate variation during deep breathing. Sympathetic tests assessed BP response to standing and Sustained Hand Grip. The heart rate and R-R interval measurement were got from lead II of ECG recordings on Polyrite D. Statistical analysis was done using SPSS software. Unpaired student's t-test was used and p-value <0.05 was considered to be statistically significant. Type D students showed slightly decreased parasympathetic activity and increased sympathetic activity when compared to non-Type D students even though there was no statistically significant difference between them. There is a statistically significant decrease in valsalva ratio among females (p<0.01) when compared to males. There is a statistically significant decrease in 30:15 ratio and BP response to handgrip (p<0.05) among students with family history of hypertension and coronary artery disease when compared with students with no family history of coronary artery disease. Valsalva ratio is the most affected test in Type D students. Cardiac autonomic functions of Type D personality persons without cardiovascular disease is not different from that of non-Type D. Regular follow up studies over years are required to find if Type D personality is associated with cardiovascular risk in healthy individuals.

Association between body anthropometric parameters and indices of cardiac autonomic function among apparently healthy young adults

Background: Anthropometric parameters are useful for indexing cardiovascular variables. Objectives: This study aimed at determining the association between anthropometric parameters and autonomic cardiovascular indices (ACIs) among young adults. Materials and Methods: It was a cross-sectional descriptive study involving 204 healthy young adults who were residents of Ile-Ife. The weight (kg) and height (m) were measured with health scale while body mass index and body surface area were calculated using Quetelet index and Mosteller formula, respectively. Each participant was evaluated through a battery of procedures; systolic blood pressure (SBP) response to standing, diastolic blood pressure (DBP) response to sustained handgrip (SH), resting heart rate (RHR), heart rate (HR) variability during Valsalva maneuver, deep breathing, and change of posture while the ACIs were derived as outcome of the procedures. The relationship between the anthropometry and ACI was determined by correlation. Results: Height positively correlated with SBP response to posture (r = 0.107, P = 0.128), DBP response to SH (r = 0.143, P = 0.041), and heart rate response to deep breathing (HDB) (r = 0.043, P = 0.540). Height negatively correlated with Valsalva ratio (r = −0.022, P = 0.759), 30:15 ratio (r = −0.009, P = 0.902), and RHR (−0.152, P = 0.030). Weight correlated positively with postural change in SBP (r = 0.096, P = 0.172), DBP response to SH (r = 0.091, P = 0.197), and 30:15 ratio (r = 0.005, P = 0.948). Weight negatively correlated with HR response to deep breathing (r = −0.114, P = 0.105) and RHR (r = −0.153, P = 0.029). Conclusion: Anthropometric parameters correlated weakly with most indices of cardiac autonomic function except RHR.

Muscular Performance during different phases of Menstrual cycle

Background: Menstrual cycle is a physiological phenomenon during reproductive life of women. Its phases are influenced by alteration in the concentration of hormones such as estrogen and progesterone. Fluctuating levels of sex steroids across normal menstrual cycle affect sensory- motor association of an individual. Objective: To study muscular performance by doing hand grip strength (strength of upper limb muscles) and time to fatigue during sustained submaximal isometric handgrip strength exercise during the different phases of menstrual cycle. Materials and Methods: A cross sectional study was conducted in 50 females medical students with regular menstrual cycle of age group between 19-25 years. Muscular performance was assessed by maximum voluntary contraction and time for the onset of fatigue at 30% maximum voluntary contraction, which were recorded using hand grip strength dynamometer by using Power lab 8/30 series with dual Bioamplifier (AD Instruments Australia, Model No.ML870). Results: There is no significant change in maximum voluntary contraction in terms of handgrip strength during different phase of menstrual cycle, though there is slight increase in Secretory phase comparing to Proliferative phase and menstrual phase. The time to fatigue at 30% of MVC (maximum voluntary contraction) is more in secretory phase, but slight statistically significant change is observed between proliferative phase and menstrual phase. Conclusion: Though there is slight changes in values, as these are not statistically significant, regularly menstruating female athletes do not need to adjust their menstrual phase to maximize the performance. Keywords: Hormones; Menstrual cycle; Muscular performance; Time to fatigue

Arterial Compliance and Autonomic Functions in Adult Male Smokers.

Smoking is known to augment sympathetic activity and may lead to increased arterial stiffness. Several studies have reported association of increased sympathetic activity and arterial stiffness to cardiovascular risks among smokers. Pulse Wave Velocity (PWV) of peripheral arteries, instead of aorta can be used as a non-invasive indicator of arterial stiffness. To measure non-invasively, the autonomic functions and peripheral arterial stiffness in smokers, and to find out whether the aforementioned factors are modified by the level of physical activity in these smokers. This cross-sectional analytical study was conducted in the Department of Physiology, HIMS, Dehradun, over a period of 12 months (2013-2014) on 100 adult males (20-40 years); 50 smokers and 50 non-smokers. The parameters analysed include relevant anthropometric and cardiovascular parameters, Pulse Wave Velocity (PWV), sustained Hand Grip Test (HGT) and Heart Rate Variability (HRV) domains. Data interpretation and analysis was carried out using SPSS 17.0. Comparison of the above mentioned parameters amongst groups was done with unpaired t-test. The relationship of pack-years & physical activity with vascular functions was assessed by Pearson's correlation. Interaction of various grades of smoking and physical activity with Cardiovascular System (CVS) parameters was assessed by one-way ANOVA. Smokers had higher values of PWV (5.7±0.5m/s) as compared to non-smokers (4.8±0.4m/s) (p<0.001). ΔDBP during HGT was lower (7±3.18mmHg) among smokers as compared to non-smokers (19.4±3.5mmHg) (p<0.001). Smoking (pack-years) was positively related to PWV (r= .03) but showed a weak negative relationship with change in Diastolic Blood Pressure (ΔDBP) (r= -0.084, p=0.56) showing that, more the frequency of smoking, the more was arterial stiffening and the lesser was the sympathetic response to the HGT. The smokers had significantly higher sympathetic activity; Low Frequency (LF) & Low Frequency: High Frequency ratio (LF: HF) (p<.001) whereas High Frequency (HF) was significantly lower (p<.001) showing a decline in parasympathetic activity. Smokers demonstrated higher peripheral PWV and higher intrinsic sympathetic activity and this increase in intrinsic sympathetic activity may lead to increased arterial stiffness. Interaction of autonomic function and PWV with levels of physical activity and grades of smoking showed no significant differences, suggesting the fact that increased physical activity or reduced smoking may not have any effect on the endothelial dysfunction or CVS morbidity caused by smoking.

Blood Pressure Increases in OSA due to Maintained Neurovascular Sympathetic Transduction: Impact of CPAP.

To test the hypothesis that greater resting sympathetic activity in obstructive sleep apnea (OSA) syndrome would not induce a lesser sympathetic neurovascular transduction. Case-controlled cohort study. 33 patients with newly diagnosed OSA without comorbidities and 14 healthy controls. 6 months of continuous positive airway pressure (CPAP) treatment for OSA patients and follow-up for 9 healthy controls. We assessed resting sympathetic outflow and sympathetic neurovascular transduction. Sympathetic activity was directly measured (microneurography) at rest and in response to sustained isometric handgrip exercise. Neurovascular transduction was derived from the relationship of sympathetic activity and blood pressure to leg blood flow during exercise. Despite an elevated sympathetic activity of ∼50% in OSA compared to controls, neurovascular transduction was not different (i.e., absence of tachyphylaxis). After six months of CPAP, there were significant declines in diastolic pressure, averaging ∼4 mm Hg, and in sympathetic activity, averaging ∼20% with no change in transduction. Greater sympathetic activity in obstructive sleep apnea does not appear to be associated with lesser neurovascular transduction. Hence, elevated sympathetic outflow without lesser transduction may underlie the prevalent development of hypertension in this population that is well controlled by continuous positive airway pressure treatment.

Cardiovascular responses to isometric handgrip exercise in neurally mediated syncope

Background/Aims: Neurally mediated syncope (vasovagal) is characterized by a transient instability of neurocardiovascular reflexes. Changes in posture and physical exercise involve activation of these reflexes. We explore arterial blood pressure (BP), heart rate (HR) and cardiac output (CO) changes occurring during voluntary sustained handgrip (SHG) protocol in patients with vasovagal syncope. Methods: 14 patients with syncope (13 women, aged 31.2 ± 10.4 years), and 30 age-matched healthy subjects (20 women). Diagnosis of vasovagal syncope was based upon clinical criteria. All patients had normal physical examination and normal cardiac evaluation. Orthostatic stress testing was performed with active standing. Valsalva maneuver, baroreflex sensitivity (BRS) and BP, HR and CO changes during sub maximum force (SHG) for 3 minutes were monitored in supine position using FINAPRES. Results: No difference was found in Valsalva ratio between control (1.7 ± 0.3) and syncope group (1.7 ± 0.4) (P = 0.6), BRS was 10.9 ± 2.8 ms/mmHg in controls and 8.6 ± 6.3 ms/mmHg in syncope group (P = 0.007). During SHG, both healthy and syncope groups show significantly BP and CO increases, while HR increased in healthy subjects but did not increase significantly in syncope patients. Conclusion: In syncope patients, the increase in BP with blunted HR change during SHG suggests an abnormal modulation of vagally-mediated cardiac baroreflex responses.

Complementary activation of the ipsilateral primary motor cortex during a sustained handgrip task.

Near-infrared spectroscopy (NIRS) can be used to examine bilateral motor cortex activation during a sustained motor task in brain areas where increased oxygenation reflects cortical activation. This study examines the time course of activation of the bilateral motor cortex during a moderate-intensity handgrip task. Ten healthy right-handed male subjects participated in this study. Functional NIRS probes were placed over the cortex to measure motor cortical activations while the subjects performed a 180-s handgrip task incrementally [30-60% of the maximal voluntary contraction (MVC) at 0.17% increase/s] Contralateral primary motor cortex (ContraM1) oxygenation values significantly increased from baseline between 40 and 120 s after the start of the motor task (p < 0.05). Moreover, the ipsilateral primary motor cortex (IpsiM1) oxygenation values significantly increased from baseline between 140 and 180 s after the start of the motor task (p < 0.05). IpsiM1 oxygenation gradually increased from 140 to 180 s, whereas ContraM1 oxygenation gradually decreased from 120 to 180 s after the start of the motor task. These results suggest that the complementary functions of IpsiM1 become activated in response to the working of the ContraM1 during a continuous handgrip task.

Relationship of Sympathetic Dysfunction with Disease Duration In Female Rheumatoid Arthritis Patients

Background: Association of increased cardiovascular morbidity and higher sympathetic activity in patients with Rheumatoid arthritis (RA) has been well recognized.Objective: To assess sympathetic nerve function status in Rheumatoid arthritis patients and its relationship to duration of the disease.Methods: This study was carried out in the dept of Physiology Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka during 2010.Sixty female RA patients aged 18-50 years with duration of disease from 1 to 10 years was selected from Rheumatology wing of Medicine OPD of BSMMU. Age and BMI matched female apparently healthy subjects were control. Sympathetic nerve function status was assessed by blood pressure response to orthostatic test and sustained hand grip isometric exercise test. In these two tests, fall in systolic blood pressure (SBP) and rise in diastolic blood pressure (DBP) respectively estimates sympathetic reactivity. For statistical analysis, unpaired students t test and pearsons correlation coefficient test was applied.Results: Mean values of fall of SBP was higher and rise of DBP was lower in RA patients compared to control which was statistically (P&lt;0.001) significant. Again rise of DBP was negatively and fall of SBP was positively correlated with duration of the disease and the relationships were statistically highly significant (p&lt;0.01).Conclusion: The results conclude that sympathetic reflex response was reduced in RA which was deteriorated with duration of disease.Bangladesh Soc Physiol. 2015, June; 10(1): 17-20

Echocardiographic findings in adult Nigerian sickle cell patients with cardiovascular autonomic dysfunction

Abstract Introduction Involvement of the cardiovascular autonomic nervous system in various diseases is often associated with increased morbidity and mortality. Aim This study was aimed at determining the relationship between cardiovascular autonomic dysfunction (CAD) and echocardiographic indices of cardiac function in adult Nigerian sickle cell anaemia patients. Material and methods A cross sectional study was done using 62 sickle cell anaemia patients and 62 age and sex matched normal controls. CAD was determined based on abnormal values in at least two of five non-invasive tests: Valsalva manoeuver, heart rate variation during deep breathing, heart rate response to standing, blood pressure response to sustained hand grip, and blood pressure response to standing. The subjects were subsequently evaluated with echocardiography. Results and discussion Significant increases in left ventricular posterior wall thickness, left ventricular mass as well as left ventricular mass index were found in patients with CAD. Indices of left ventricular diastolic and systolic functions were comparable in patients with and without CAD, however patients with CAD had lower peak aortic systolic velocity (P = 0.038). Valsalva ratio correlated significantly with right ventricular internal diameter (r = −0.388; P = 0.009), left ventricular posterior wall diameter (r = −0.352; P = 0.019), left ventricular end systolic stress/end systolic dimension ratio (r = 0.512; P Conclusions CAD is a serious complication of sickle cell anaemia. All the patients should be routinely evaluated for CAD.

Non-Invasive Assessment of Cardiac Autonomic Functions in Healthy Young Adults in Ile-Ife, South-Western Nigeria

Background: This study assessed the responses of Blood Pressure (BP) and Heart Rate (HR) to change of posture, Sustained Handgrip (SH),deep breathing(DB) and Valsalva manoeuvre (VM) in order to determining the normal limits and pattern of Autonomic Cardiovascular Indices (ACI) among healthy young adults. Methods: Two hundred and four volunteer (98 men and 106 women) aged 18- 40 years (mean, 22.45 ± 4.86 years) participated in the study. After excluding systemic diseases by clinical evaluation, each participant performed five non-invasive cardiac autonomic function tests in series. Differences in supine and erect systolic BPs were assessed by sphygmomanometry, diastolic BP responses to SH were determined by dynamometry while HR variability in response to VM, DB and postural change were assessed by continuous electrocardiogram. Normal limits of ACI were determined at 5th and 95th percentiles. Results: The mean (normal limits) for SBP response to change of posture (mmHg); DBP response to sustained handgrip (mmHg); Valsalva ratio; heart rate response to deep breathing (beats per minute); PTI; tachycardia ratio; bradycardia ratio and RHR(beats per minute) respectively were: -4.26 ± 9.17(-19.00-11.00); 20.14 ± 17.35(0.00-54.00); 1.55 ± 0.40(1.10-2.40); 31.82 ± 10.81(13.0048.75); 1.41 ± 0.31(1.08-1.84); 0.80 ± 0.12(0.58-1.00); 1.21 ± 0.20(0.95-1.60) and 70.61 ± 12.23(53.00-93.00). During Valsalva maneouvre, Post-Strain Pause (PSP) which ranged from 1.2812.76s was observed in 14(6.86%) of the participants. PSP occurred more frequently in women (9.43%) than men (4.08%). No significant gender difference in the duration of post-strain pause (t=-1.628, p=0.105). In majority of the participants (67.6%), an elevation of SBP occurred within 2minutes of rising from supine to erect position. Immediate Post-Standing Pause (IPSP) occurred among 139 (68.14%) participants. Conclusion: Non-invasive assessment of cardiac autonomic function is feasible in Nigeria. Increase rather than decrease in systolic blood pressure response occurred more frequently upon a change from supine to erect posture. IPSP was a unique pattern of cardiac autonomic functions in study population.

Abnormal cardiovascular sympathetic and parasympathetic responses to physical and emotional stimuli in depersonalization disorder.

Depersonalization disorder (DPD) is characterized by a subjective sense of unreality, disembodiment, emotional numbing and reduced psychogenic (sudomotor) sympathoexcitation. Three related experiments utilized escalating physical and emotional challenges in 14 DPD participants and 16 controls aimed to elucidate (i) whether the cardiovascular sympathetic (SNS) and parasympathetic (PNS) nervous systems are implicated in DPD pathophysiology and (ii) if possible, to determine whether the blunted sympathoexcitation in DPD is peripherally or centrally mediated. Participants completed the Beck Anxiety Inventory (BAI), Dissociative Experience Scale (DES), and Cambridge Depersonalization Scale (CDS). Study I recorded heart rate (HR) and blood pressure (BP) during 5 min supine baseline, 3 min sustained handgrip (HG), 3 min cold pressor (CP) and 5 min 60° head-up tilt (HUT). In study II, HR, BP, and heart rate variability (HRV) were recorded during 5 min simultaneous 60° HUT and continuous presentation of unpleasant images (5 s per image). Study III examined HR and BP orienting responses (ORs) to simultaneous 60° HUT and pseudorandom presentation of unpleasant, neutral and pleasant images (5 s per image 3 min 25 s). OR data was grouped by image valence post hoc. DPD BAI (p = 0.0004), DES (p = 0.0002), and CDS (p ≤ 0.0001) scores were higher than controls. The DPD group produced diminished diastolic BP (DBP) (p = 0.045) increases to HG. Other indices were comparable between groups. DPD participants produced diminished systolic BP (SBP) (p = 0.003) and DBP (p = 0.002) increases, but greater (p = 0.004) HR increases to CP. In study II, DPD high frequency HRV (HF-HRV)-indicating parasympathetic vagal activity-was reduced (p = 0.029). In study III, DPD DBP was higher throughout the 5 s duration of HUT/pseudorandom unpleasant image presentation (1 s, p = 0.002, 2 s p = 0.033, 3 s p = 0.001, 4 s p = 0.009, 5 s p = 0.029). Study I's BP pressor data supports previous findings of suppressed sympathoexcitation in DPD. The greater HR increases to CP, decreased HF-HRV in study II, and increased DBP during unpleasant ORs in study III implicates the SNS and PNS in DPD pathophysiology. These studies suggest the cardiovascular autonomic dysregulation in DPD is likely to be centrally-mediated.

Cardiovascular autonomic testing performed with a new integrated instrumental approach is useful in differentiating MSA-P from PD at an early stage.

To evaluate whether a battery of cardiovascular autonomic tests (Ewing's battery, EB) performed with a new integrated instrumental approach is useful in differentiating multiple system atrophy with predominant parkinsonism (MSA-P) from Parkinson's disease (PD) at an early stage. We retrospectively analyzed EB tests of all the patients (n=99) with a parkinsonian syndrome referred to our clinic who performed EB during the first diagnostic workup and were subsequently evaluated at least once a year until a final diagnosis of MSA-P (n=34) or PD (n=65). Thirty-eight controls matched for age and sex were included. EB consisted of head-up tilt test (HUTT), Valsalva manoeuvre (VM), deep breathing, and sustained handgrip whose correct execution and results were checked and obtained automatically. Results were compared between groups. Discriminant analysis was performed to identify MSA-P or PD patients. Orthostatic hypotension was found in 22 MSA-P and 3 PD patients. Cardiovascular reflexes indices were significantly more affected in MSA-P compared to PD and controls. EB presented a 91% sensitivity and 94% specificity in the differentiation of MSA-P and PD. HUTT+VM presented a 91% sensitivity and 92% specificity. Our results suggest that EB or HUTT+VM performed with an integrated instrumental approach and analyzed with the discriminant procedure may distinguish MSA-P from PD at an early stage and might improve the accuracy of current diagnostic criteria. However, a validation in separate samples and prospective studies is needed.

6. Neurophysiological methods of autonomic nervous system testing in multiple sclerosis

Autonomic dysfunction (AD) is commonly seen in patients with multiple sclerosis (MS). The most common manifestations of AD in MS patients include bladder or bowel dysfunction, impairment of sexual performance, pupillomotor or sweating alterations and orthostatic hypotension. Furthermore, AD is supposed to be related to fatigue. The incidence and severity of the symptoms related to AD correlated with the degree of disability. The lifetime prevalence of autonomic impairment reaches up to 80 % in MS population. Besides medical history and validated questionnaires, neurophysiological testing of cardiovascular and sudomotor functions are most commonly used for evaluation of autonomic nervous system impairment in MS patients. Of the cardiovascular tests, analysis of heart-rate variability in the time- and frequency-domain has repeatedly been published as a suitable method for evaluation of cardiovascular autonomic nervous system status in MS patients (the latter being mainly represented by spectral analysis of heart-rate variability). Autonomic challenge manoeuvres (suited for activation of sympathetic or parasympathetic nervous system) are also frequently used for this purpose and comprise Valsalva manoeuvre, deep metronomic breathing, response to active standing, sustained handgrip test, cold pressor test or cold face test. Furthermore, orthostatic challenge testing represented by head-up tilting (besides above mentioned active standing) can be useful in MS patients. Sudomotor functions in MS are most frequently tested using the sympathetic skin response (mainly because of wide availability of testing equipment), which seems to be less sensitive comparing cardiovascular tests. The availability of other testing methods, which may be used for the sweating evaluation (thermoregulatory sweat test, quantitative sudomotor axon reflex or similar tests) is lower, but they seem to have higher sensitivity in evaluation of sudomotor dysfunction in multiple sclerosis.

Arterial spin labeling CMR perfusion imaging is capable of continuously monitoring myocardial blood flow during stress

Background Myocardial arterial spin labeling (ASL) is a non-invasive non-contrast CMR perfusion imaging technique [Zun et al., ‘09] that is compatible with adenosine stress testing [Zun et al., ‘11]. Here, we demonstrate its ability to continuously monitor MBF during stress, which has a variety of potential applications including interventional CMR and the study of endothelial function. We used mild sustained isometric handgrip stress.

A comparative study of autonomic function tests in normotensive premenopausal and postmenopausal women

|| ABSTRACT Background: Premenopause is a term that encompasses the entire reproductive period up to final menstrual period, whereas menopause is the permanent cessation of menstruation. Menopause is ‘‘burning out of ovaries.’’ After menopause, the primordial follicles become atretic; hence, the ovaries fail completely to produce estrogen. The presence of estrogen receptors in the heart, vascular smooth muscles, and autonomic brainstem centers establishes a probable participation in the regulation of cardiovascular system. Aims and Objective: To compare the autonomic function tests in premenopausal and postmenopausal women. Materials and Methods: The autonomic function tests in 60 premenopausal women (25–45 years) and 60 postmenopausal women (45–60 years) were compared. The following parameters were studied: (i) body mass index (BMI); (ii) waist–hip ratio (WHR); (iii) Parasympathetic function tests—(a) heart rate response to postural change (30:15 ratio), (b) heart rate variation during deep breathing, and (c) Valsalva maneuver test; and iv) sympathetic function tests—(a) orthostatic tolerance test, (b) sustained isometric handgrip test, and (c) cold pressor test. Result: (1) BMI and WHR significantly increased in the postmenopausal women when compared with the premenopausal women. (2) The 30:15 ratio significantly decreased in the postmenopausal women when compared with the premenopausal women whereas heart rate variation during deep breathing and Valsalva maneuver test did not show any significant change. (3) All the sympathetic function test results significantly increased in the postmenopausal women when compared with premenopausal women. Conclusion: This finding showed an increased tendency of obesity and autonomic imbalance with sympathetic overactivity in the postmenopausal women when compared with the premenopausal women.

Alteration of autonomic function is associated with disease severity in patients with bronchial asthma

Background and Aim: Abnormality in the autonomic regulation of the airway results in airway obstruction in bronchial asthma. However, autonomic abnormality in asthmatic patients is generalized and is not confined to airway only. Therefore, the present study was conducted to assess the abnormality of autonomic nervous system (ANS) and its association with disease severity in bronchial asthma patients. Methods: Sixty patients of bronchial asthma aged between 15 and 50 years were included in the study. After taking informed consent, the duration of asthma was noted in each of these patients and six noninvasive ANS testing namely deep breathing test, orthostatic test, 30:15 ratio, sustained hand grip test, valsalva manoeuvre and cold pressure test was performed. Results: The study population consisted of 60 bronchial asthma patients (34 males and 26 females) and 60 controls (32 males and 28 females). It was found that out of 60 patients, 46 patients had abnormal autonomic function test values ( P P Conclusion: Bronchial asthma patients displayed definitive dysfunction of ANS as compared with age and sex-matched controls. With severity and chronicity of asthma, the autonomic function was proportionately attenuated. Parasympathetic overactivity appears to be closely linked to the severity of bronchial asthma.

Abstract 18257: Cardiovascular Response to Energy Drink Consumption in Healthy Adults

Introduction: An increasing number of healthy adults consume energy drinks to enhance their physical and mental performance. Energy drinks contain caffeine and multiple other “natural” stimulants and their combined effects on cardiac hemodynamics in healthy individuals are unclear. Hypothesis: We hypothesized that drinking a commercially available energy drink, Rockstar , compared to a placebo drink, increases resting blood pressure and heart rate in healthy adults, and these increases would be further accentuated by stress conditions. Methods: We enrolled 25 healthy, normotensive subjects (14 males), aged 29±1 years, with body mass index 24.5±1 kg/m 2 , in a randomized, double-blind, placebo-controlled, crossover study. Each subject consumed a placebo drink and a commercially available Rockstar energy drink (473 ml), in random order on two separate study days. Blood pressure and heart rate responses were recorded and compared before and 30 minutes after drink consumption, both at rest and then in response to physical, mental and cold stressors. Results: The Rockstar energy drink induced a 6±1% increase in resting systolic blood pressure, compared to 3±1% with the placebo drink (P=0.0078). Diastolic blood pressure increased by 7±1% vs 0±1% with the placebo drink (P=0.0007; Figure 1). Heart rate increased similarly in both groups, by 5±2% in the energy drink group vs. 7±2% in the placebo group. Blood pressure and heart rate increases during the stress stimuli (sustained handgrip, mental stress and cold stress) did not differ between energy drink and placebo. Conclusions: Drinking a commercially available Rockstar energy drink significantly increases resting blood pressure in young healthy adults. Blood pressure increases are not further accentuated by exercise, mental or cold pressor stress stimuli. These hemodynamic changes induced by energy drink consumption could predispose to cardiovascular events.

Cardiovascular autonomic neuropathy in rheumatoid arthritis assessed by cardiovascular autonomic function tests: A cross-sectional survey.

Objective:In this study, we aimed to evaluate cardiovascular autonomic neuropathy (CAN) in RA patients by cardiovascular autonomic function tests. Because CAN was reported of patients with automimmune rheumatic diseases those may in sudden death or myocardial infarction.Methods:A total of 44 patients with RA and 44 age-and sex-matched healthy volunteers participated in this cross-sectional study. Assessment of CAN was performed using cardiovascular reflex tests. These five tests were: 1) beat-to-beat heart rate variation during deep breathing; 2) heart rate response to standing up; 3) heart rate response to the Valsalva maneuver; 4) blood pressure response to standing up; and 5) blood pressure response to sustained handgrip.Results:The mean age was 43.15 (SD, 12.18) years (range, 23-68 years) in the RA group, and 38 were women. In beat-to-beat heart rate variation during deep breathing, expiration-to-inspiration ratio was abnormal in 3 cases with RA (6.8%) but in 1 (2.3%) control subject (p=0.3), and maximum minus minimum heart rate was abnormal in 8 patients (18.2%) and in 3 (6.8%) control subjects (p=0.1). 2) In heart rate response to standing up, all patients and controls had normal results. Valsalva ratio was abnormal in 7 RA patients (15.9%) and in 7 control subjects (15.9%). Blood pressure response to standing up was normal in RA patients but abnormal in 1 (2.3%) control subject (p=0.4). Blood pressure response to sustained handgrip was abnormal in 5 RA patients (11.4%) and 2 (4.6%) control subjects (p=0.2).Conclusion:Our study failed to show any statistically significant difference between cardiovascular autonomic function tests in RA patients with control subjects by our test done.

English

AIM AND OBJECTIVES OF THE STUDY: The present study is aimed at detecting the association of autonomic dysfunction occurs in chronic severe anemia. All patients with hemoglobin less than 6 gm % and symptoms referable to anemia for > 6 months duration were included in the study. Patients with cardiac, hepatic, renal disease, leprosy, hypertension, diabetes mellitus and those on sympathomimetic, parasympatholytic, antihypertensive drugs and also patients below the age of 13 year were excluded from the study. Sample size is 50. RESULTS AND CONCULUSIONS: A total of fifty patients were included in the study. Among them, 20 (40%) were males and 30(60%) were females with male to female ratio of 1:1.5. majority of the patients were in the age group of 21- 30years with mean age of 33 years. Dimorphic anemia was the most frequent type of anemia in 56% of cases: microcytic hypochromic anemia 42% and macrocytic seen only in 2%. Resting tachycardia of more than 100 per min was observed in 62% cases. Most of the cases (86%) had prolonged QTc interval of more than 0.40sec. 44% cases had abnormal valsalva response, 60% had abnormal 30/15 ratio, inspiration and expiration ratio was abnormal in 38% cases, and postural hypotension was observed in 86% cases. Diastolic raise in blood pressure to sustained hand grip was abnormal in 78% cases. Atropine test was abnormal in 26% cases. Two or more autonomic function tests were abnormal in all the cases. All the cases had combined sympathetic and parasympathetic involvement. 42% cases had involvement of afferent limb of parasympathetic reflex arc. The common abnormality found in cases of chronic severe anemia are postural hypotension and abnormal heart rate response to valsalva and standing are due to blunting of carotid body chemoreceptor and baroreceptor

Association between Brachial-Ankle pulse wave velocity and cardiac autonomic neuropathy in type 2 diabetes.

BackgroundCardiac autonomic neuropathy (CAN) is a common complication of type 2 diabetes mellitus (T2DM). Brachial-ankle pulse wave velocity (baPWV) is known to be a good surrogate marker of vascular damages. The goal of this study was to investigate the relationship between BaPWV and CAN in T2DM.MethodsA total of 148 patients who had no apparent history of cardiovascular condition were enrolled consecutively in this study. The correlation between increased baPWV and CAN was analyzed. CAN was evaluated by five standard cardiovascular reflex tests (CARTs) according to the Ewing's protocol: 1) heart rate variation during deep breathing, 2) heart rate response to standing, 3) Valsalva maneuver, 4) postural systolic blood pressure (BP) change, 5) Sustained handgrip test. CAN was defined as the presence of at least two abnormal tests.ResultsThe mean age of patients was 59.8 ± 7.8 years. The mean duration of diabetes was 6.0(2.0-11.0) years. The mean baPWV was 1665.5(1482.0-1940.0) cm/sec. Subjects with CAN were older and had high BMI, baPWV compared with those without CAN. The proportion of patients with diabetic peripheral neuropathy was higher in subjects with CAN. After adjusting for other confounding risk factors, baPWV (odds ratio = 8.496, 95% CI: 1.216-59.348; P = 0.031) remained as independent risk factors for CAN. The number of abnormal CARTs increased gradually with increasing baPWV (correlation coefficient =0.255, p = 0.002).ConclusionIncreased baPWV was significantly correlated with CAN in patients with type 2 diabetes.