scholarly journals A single dose of dark chocolate increases parasympathetic modulation and heart rate variability in healthy subjects

2016 ◽  
Vol 29 (6) ◽  
pp. 765-773 ◽  
Author(s):  
Ana Amélia Machado DUARTE ◽  
Cristiano MOSTARDA ◽  
Maria Claudia IRIGOYEN ◽  
Katya RIGATTO

ABSTRACT Objective: The aim of this study was to investigate the acute effect of a single dose of dark chocolate (70% cocoa) on blood pressure and heart rate variability. Methods: Thirty-one healthy subjects (aged 18-25 years; both sexes) were divided into two groups: 10 subjects in the white chocolate (7.4 g) group and 21 in the dark chocolate (10 g) group; measurements were performed at the university's physiology lab. An electrocardiogram measured the sympathovagal balance by spectral and symbolic analysis. Results: A single dose of dark chocolate significantly reduced systolic blood pressure and heart rate. After consuming 10 g of dark chocolate, significant increases were observed for heart rate variability, standard deviation of RR intervals standard deviation of all NN intervals, square root of the mean squared differences between adjacent normal RR intervals root mean square of successive differences, and an increase in the high frequency component in absolute values, representing the parasympathetic modulation. Conclusion: In conclusion the importance of our results lies in the magnitude of the response provoked by a single dose of cocoa. Just 10 g of cocoa triggered a significant increase in parasympathetic modulation and heart rate variability. These combined effects can potentially increase life expectancy because a reduction in heart rate variability is associated with several cardiovascular diseases and higher mortality.

2016 ◽  
Vol 27 (1) ◽  
pp. 37-45 ◽  
Author(s):  
Anne K. F. Silva ◽  
Diego G. D. Christofaro ◽  
Franciele M. Vanderlei ◽  
Marianne P. C. R. Barbosa ◽  
David M. Garner ◽  
...  

ObjectiveThe objective of this study was to verify possible associations between heart rate variability indices and physical activity, body composition, and metabolic and cardiovascular parameters in individuals with type 1 diabetes.MethodA total of 39 young patients with type 1 diabetes were included. Body composition, physical activity, cardiovascular parameters, and metabolic parameters were assessed. For the heart rate variability analysis, heart rate was recorded beat-by-beat using a Polar S810i heart rate monitor for 30 minutes, with the volunteers in the supine position; subsequently, the following indices were considered: standard deviation of all normal RR intervals; root-mean square of differences between adjacent normal RR intervals in a time interval; percentage of adjacent RR intervals with a difference of duration >50 ms; high frequency component in milliseconds squared; high frequency component in normalised units; standard deviation of the instantaneous variability beat-to-beat; and standard deviation of the long-term variability. The association between the heart rate variability indices and independent variables was verified through linear regression in unadjusted and adjusted models (considering gender and age). The statistical significance was set at 5% and the confidence interval at 95%.ResultsHigh values of at-rest heart rate were associated with reduced parasympathetic activity and global heart rate variability, and higher values of waist-to-hip ratio were related to lower parasympathetic activity, independent of age or gender.ConclusionFor young patients with type 1 diabetes, increases in at-rest heart rate values are associated with reduced parasympathetic activity and global heart rate variability, whereas higher waist-to-hip ratio values are related to lower parasympathetic activity, both independent of age and gender.


1998 ◽  
Vol 84 (2) ◽  
pp. 576-583 ◽  
Author(s):  
Tomi Laitinen ◽  
Juha Hartikainen ◽  
Esko Vanninen ◽  
Leo Niskanen ◽  
Ghislaine Geelen ◽  
...  

Laitinen, Tomi, Juha Hartikainen, Esko Vanninen, Leo Niskanen, Ghislaine Geelen, and Esko Länsimies. Age and gender dependency of baroreflex sensitivity in healthy subjects. J. Appl. Physiol. 84(2): 576–583, 1998.—We evaluated the correlates of baroreflex sensitivity (BRS) in healthy subjects. The study consisted of 117 healthy, normal-weight, nonsmoking male and female subjects aged 23–77 yr. Baroreflex control of heart rate was measured by using the phenylephrine bolus-injection technique. Frequency- and time-domain analysis of heart rate variability and an exercise test were performed. Plasma norepinephrine, epinephrine, insulin, and arginine vasopressin concentrations and plasma renin activity were measured. In the univariate analysis, BRS correlated with age ( r = −0.65, P < 0.001), diastolic blood pressure ( r = −0.47, P < 0.001), exercise capacity ( r = 0.60, P < 0.001), and the high-frequency component of heart rate variability ( r= 0.64, P < 0.001). There was also a significant correlation between BRS and plasma norepinephrine concentration ( r = −0.22, P < 0.05) and plasma renin activity ( r = 0.32, P < 0.001). According to the multivariate analysis, age and gender were the most important physiological correlates of BRS. They accounted for 52% of interindividual BRS variation. In addition, diastolic blood pressure and high-frequency component of heart rate variability were significant independent correlates of BRS. BRS was significantly higher in men than in women (15.0 ± 1.2 vs. 10.2 ± 1.1 ms/mmHg, respectively; P < 0.01). Twenty-four percent of women >40 yr old and 18% of men >60 yr old had markedly depressed BRS (<3 ms/mmHg). We conclude that physiological factors, particularly age and gender, have significant impact on BRS in healthy subjects. In addition, we demonstrate that BRS values that have been proposed to be useful in identifying postinfarction patients at high risk of sudden death are frequently found in healthy subjects.


2017 ◽  
Vol 17 (2) ◽  
pp. 5-14 ◽  
Author(s):  
Milana Drumond Ramos Santana ◽  
Eli Carlos Martiniano ◽  
Larissa Raylane Lucas Monteiro ◽  
Maria Do Socorro Santos De Oliveira ◽  
Vitor E. Valenti ◽  
...  

AbstractIntroduction: There is an increase in level of stress in the general population because of the social, personal and professional demands. Currently, there are only simple tools that can safely measure this stress such as levels of cortisol and heart rate variability (HRV). Objective: To analyze the relationship between salivary cortisol and the cardiac autonomic modulation. Methods: A total of fifty-one male and female subjects between 18 and 40 years old were evaluated. Saliva collection was achieved for the salivary cortisol dosage. The collection was performed through the SalivetteR tube. After this collection, the median cortisol levels (0.24 ug/dl) were analyzed and the volunteers were divided into two groups: i) cortisol below the mediane ii) cortisol above the median. After this division, each group consisted of 25 volunteers and then was verified the following information: age, gender, weight, height, body mass index (BMI), blood pressure. Shortly thereafter was assessment of cardiac autonomic modulation por meio da HRV. The Polar RS800cx heart rate receiver was placed on the chest of the volunteers, in the vicinity of the distal third of the sternum. The volunteers were instructed to remain in rest with spontaneous breathing in dorsal position for 20 minutes. HRV analysis included geometric, time and frequency domain indices. Results: There were no statistical differences for the two groups regarding systolic and diastolic blood pressure, heart rate, RR intervals or linear and frequency indices for the volunteers. In addition, also there was no correlation the cortisol with the analyzed variables (SAP, p=0.460; DAP, p = 0.270; HR, p = 0.360; RR, p = 0.380; SDNN, p = 0.510; rMSSD, p = 0.660; pNN50, p = 0.820; RRtri, p = 0.170; TINN, p = 0.470; SD1, p = 0.650; SD2, p = 0.500; LF [ms2], p = 0.880; LF [nu], p = 0.970; HF [ms2], p = 0.870; HF [nu], p = 0.960; LF/HF, p = 0.380 Conclusion: Heart rate variability autonomic control was unchanged in healthy subjects with physiological distribution of salivary cortisol levels. There was no association between normal salivary cortisol and resting autonomic regulation of heart rate.


2020 ◽  
Vol 14 (2) ◽  
pp. 82-88
Author(s):  
Musfika Mostafa ◽  
Sultana Ferdousi ◽  
Shamima Sultana ◽  
Ayesha Akhter

Background: Polycystic ovary syndrome (PCOS) is one of the most common, heterogeneous endocrine disorder of reproductive aged women. Association of autonomic impairment and elevated oxidative stress may predispose these patients to increased cardiovascular risks. Objective: To evaluate the relationship between cardiac autonomic nerve function (CANF) and oxidative stress in patients with PCOS. Methods: This cross sectional study was conducted in Department of Physiology, Bangabandhu Sheikh Mujib Medical University (BSMMU), Shahbag, Dhaka from September, 2018 to August, 2019. For this study, 30 newly diagnosed PCOS patients aged 20-35 years were recruited and similar age, body mass index (BMI) 30 apparently healthy, regularly menstruating women were enrolled as control. CANF was assessed by analyzing time domain measures of Heart Rate Variability (HRV). HRV data were recorded by a digital data acquisition device, Powerlab 8/35 (AD instruments, Australia). For evaluation of oxidative stress, plasma catalase and plasma Malondialdehyde (MDA) levels were measured. Statistical analysis was done by unpaired “t” test and Pearson’s correlation test as applicable. Results: In this study, resting pulse rate, systolic blood pressure (SBP), diastolic blood pressure (DBP) were significantly higher (p<0.001, p<0.01, p<0.01 respectively) and standard deviation of the RR intervals (SDRR) (p<0.01), mean R-R interval, standard deviation of the difference between successive RR intervals (SDSD), square root of mean squared differences of successive RR intervals (RMSSD), proportion of RR interval with duration >50 ms (pRR50%) were significantly lower (p<0.001) in PCOS than healthy controls. In addition, plasma catalase was significantly lower (p<0.01) and plasma MDA was significantly higher (p<0.001) in PCOS patients compared to controls. On correlation analysis, mean heart rate, SDRR, SDSD, RMSSD and pRR50% showed negative correlation with plasma catalase and plasma MDA (p<0.05) in PCOS patients but these were not significant. Conclusion: The present study reveals that reduced parasympathetic activity in PCOS patients may be related to oxidative stress. J Bangladesh Soc Physiol. 2019, December; 14(2): 82-88


2021 ◽  
Vol 12 ◽  
Author(s):  
David C. Sheridan ◽  
Karyssa N. Domingo ◽  
Ryan Dehart ◽  
Steven D. Baker

Heart rate variability (HRV) evaluates beat-to-beat interval (BBI) differences and is a suggested marker of the autonomic nervous system with diagnostic/monitoring capabilities in mental health; especially parasympathetic measures. The standard duration for short-term HRV analysis ranges from 24 h down to 5-min. However, wearable technology, mainly wrist devices, have large amounts of motion at times resulting in need for shorter duration of monitoring. The objective of this study was to evaluate the correlation between 1 and 5 min segments of continuous HRV data collected simultaneously on the same patient. Subjects wore a patch electrocardiograph (Cardea Solo, Inc.) over a 1–7 day period. For every consecutive hour the patch was worn, we selected a 5-min, artifact-free electrocardiogram segment. HRV metric calculation was performed to the entire 5-min segment and the first 1-min from this same 5-min segment. There were 492 h of electrocardiogram data collected allowing calculation of 492 5 min and 1 min segments. 1 min segments of data showed good correlation to 5 min segments in both time and frequency domains: root mean square of successive difference (RMSSD) (R = 0.92), high frequency component (HF) (R = 0.90), low frequency component (LF) (R = 0.71), and standard deviation of NN intervals (SDNN) (R = 0.63). Mental health research focused on parasympathetic HRV metrics, HF and RMSSD, may be accomplished through smaller time windows of recording, making wearable technology possible for monitoring.


2015 ◽  
Vol 9 (2) ◽  
pp. 78-82 ◽  
Author(s):  
Qazi Farzana Akhter ◽  
Qazi Shamima Akhter ◽  
Farhana Rohman ◽  
Susmita Sinha ◽  
Sybilla Ferdousi

Background: Heart rate variability has been considered as an indicator of autonomic nerve function status. Few works have been done to assess the heart rate variability in normal healthy subjects in different countries. Objectives: To assess the cardiac autonomic nerve function status in healthy Bangladeshi population of different age groups by analyzing time domain measures of Heart Rate Variability. Methods: This cross sectional study was conducted in the Department of Physiology, Dhaka Medical College, Dhaka from the period of July 2012 to June 2013. For this purpose, a total number of 180 healthy subjects were selected with the age ranging from 15-60 years of both sexes. All the study subjects were divided into 3 different groups according to age (Control 15-30 years; middle age 31-45 years; older age 46-60 years). Each group included 60 subjects of which 30 were male and 30 were female. The subjects were selected from different areas of Dhaka city by personal contacts. HRV parameters were recorded by a 4 active channels, RMS Polyrite-D-2 machine For statistical analysis, one way ANOVA, unpaired Student’s ‘t’-test and Pearson’s correlation coefficient test were performed. as applicable. Results: Systolic blood pressure (SBP), diastolic blood pressure (DBP) were significantly (p<0.001) higher in older group in comparison to control & middle age group. Again RR interval and RMSSD (p<0.001), were significantly lower in older age group (p<0.05) compared to control & also to middle age group. But HR was found significantly higher (p<0.05)in both middle and older subjects than control and also in older (p<0.05) compared to middle age. Correlation analysis showed moderate negative correlation of mean R-R with age in middle age whereas significant negative correlation for RMSSD both in middle and older age subjects. Conclusion: In this study, markedly decreased cardiac parasympathetic function were found with aging process. DOI: http://dx.doi.org/10.3329/jbsp.v9i2.22801 Bangladesh Soc Physiol. 2014, December; 9(2): 78-82


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