scholarly journals Heritability and the Genetic Correlation of Heart Rate Variability and Blood Pressure in >29 000 Families

Hypertension ◽  
2020 ◽  
Vol 76 (4) ◽  
pp. 1256-1262
Author(s):  
Balewgizie S. Tegegne ◽  
Tengfei Man ◽  
Arie M. van Roon ◽  
Nigus G. Asefa ◽  
Harriëtte Riese ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Genetic Correlation ◽  
Root Mean Square ◽  
Genome Wide Association Study ◽  
Genetic Correlations ◽  
Substantial Contribution ◽  
Mean Square ◽  
Cardiac Autonomic Nervous System

Dysregulation of the cardiac autonomic nervous system, as indexed by reduced heart rate variability (HRV), has been associated with the development of high blood pressure (BP). However, the underlying pathological mechanisms are not yet fully understood. This study aimed to estimate heritability of HRV and BP and to determine their genetic overlap. We used baseline data of the 3-generation Lifelines population-based cohort study (n=149 067; mean age, 44.5). In-house software was used to calculate root mean square of successive differences and SD of normal-to-normal intervals as indices of HRV based on 10-second resting ECGs. BP was recorded with an automatic BP monitor. We estimated heritabilities and genetic correlations with variance components methods in ASReml software. We additionally estimated genetic correlations with bivariate linkage disequilibrium score regression using publicly available genome-wide association study data. The heritability (SE) estimates were 15.6% (0.90%) for SD of normal-to-normal intervals and 17.9% (0.90%) for root mean square of successive differences. For BP measures, they ranged from 24.4% (0.90%) for pulse pressure to 30.3% (0.90%) for diastolic BP. Significant negative genetic correlations (all P <0.0001) of root mean square of successive differences/SD of normal-to-normal intervals with systolic BP (−0.20/−0.16) and with diastolic BP (−0.15/−0.13) were observed. LD score regression showed largely consistent genetic correlation estimates of root mean square of successive differences/SD of normal-to-normal intervals with systolic BP (range, −0.08 to −0.23) and diastolic BP (range, −0.20 to −0.27). Our study shows a substantial contribution of genetic factors in explaining the variance of HRV and BP measures in the general population. The significant negative genetic correlations between HRV and BP indicate that genetic pathways for HRV and BP partially overlap.

scholarly journals Prolonged (48-Hour) Modest Hyperinsulinemia Decreases Nocturnal Heart Rate Variability and Attenuates the Nocturnal Decrease in Blood Pressure in Lean, Normotensive Humans

2006 ◽  
Vol 91 (3) ◽  
pp. 851-859 ◽  
Author(s):  
Maja Petrova ◽  
Raymond Townsend ◽  
Karen L. Teff
Keyword(s):  
Metabolic Disease ◽  
Blood Pressure ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Root Mean Square ◽  
Glucose Infusion ◽  
Vagal Activity ◽  
Model Assessment ◽  
Mean Square ◽  
Homeostasis Model Assessment

Abstract Context: Heart rate variability (HRV), an index of cardiac vagal activity, is decreased in individuals with metabolic disease. The relationship between decreased HRV and metabolic disease is unclear. Objective: The objective of this study was to determine whether experimentally induced glucose intolerance decreases HRV in a circadian relevant manner in healthy individuals. Design: This was a within-subject, randomized design study with subjects infused for 48 h with saline (50 ml/h) or 15% glucose (200 mg/m2·min). HRV was evaluated using time domain measurements taken over the 48-h period. Blood pressure and heart rate were monitored, and blood samples were taken. Setting: This study was performed at the General Clinical Research Center of the Hospital of the University of Pennsylvania. Patients: Sixteen healthy subjects (eight men and eight women; 18–30 yr old; mean body mass index, 21.7 ± 1.6 kg/m2) were studied. Results: After glucose infusion, mean plasma glucose was increased by 16.8% (P &lt; 0.0001), and plasma insulin was increased by 99.4% (P &lt; 0.0001) compared with after saline infusion. Significant decreases in homeostasis model assessment indicated a decrease in insulin sensitivity (saline, 0.52 + 0.13; glucose, 0.34 + 0.12; P &lt; 0.0001). The nocturnal root mean square successive difference, an index of cardiac vagal activity, was significantly decreased (P &lt; 0.01), and nocturnal HR (P &lt; 0.001) and blood pressure were significantly elevated (saline, 107.4 ± 2.7; glucose, 112.5 ± 3.3 mm Hg; P &lt; 0.05) compared with the saline control. The change in homeostasis model assessment due to glucose infusion was significantly correlated with the change in root mean square successive difference (r = 0.48; P &lt; 0.01). Conclusions: Prolonged mild hyperinsulinemia disrupts the circadian rhythm of cardiac autonomic activity. Early changes in the neural control of cardiac activity may provide a potential mechanism mediating the pathophysiological link between impaired glucose tolerance and cardiovascular disease.

scholarly journals Exploring the relationship between schizophrenia and cardiovascular disease: A genetic correlation and multivariable Mendelian randomization study

2021 ◽  
Author(s):  
Rada R Veeneman ◽  
Jentien M Vermeulen ◽  
Abdel Abdellaoui ◽  
Eleanor Sanderson ◽  
Robyn E Wootton ◽  
...  
Keyword(s):  
Heart Failure ◽  
Blood Pressure ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Diastolic Blood Pressure ◽  
Mendelian Randomization ◽  
Genetic Correlations ◽  
Lipid Levels ◽  
Early Repolarization ◽  
Artery Disease

Importance: Individuals with schizophrenia have a reduced life-expectancy compared to the general population, largely due to an increased risk of cardiovascular disease (CVD). Clinical and epidemiological studies have been unable to fully unravel the nature of this relationship. Objective: Investigate genetic correlations and potential bi-directional effects between liability to schizophrenia and CVD. Design, setting, and participants: We obtained summary-data of genome-wide-association studies of schizophrenia (N=130,644), heart failure (N=977,323), coronary artery disease (N=332,477), systolic and diastolic blood pressure (N=757,601), heart rate variability (N=46,952), QT interval (N=103,331), early repolarization and dilated cardiomyopathy ECG patterns (N=63,700). We computed genetic correlations with linkage disequilibrium score regression and conducted bi-directional Mendelian randomization (MR). With multivariable MR, we investigated whether associations were mediated by smoking, body mass index, physical activity, lipid levels, or type 2 diabetes. To ensure robustness, we applied a range of sensitivity methods. Main outcomes and measures: Schizophrenia, heart failure, coronary artery disease, systolic blood pressure, diastolic blood pressure, heart rate variability, QT interval, early repolarization, dilated cardiomyopathy. Results: Genetic correlations between liability to schizophrenia and CVD were close to zero (-0.02 to 0.04). With MR, we found robust evidence that liability to schizophrenia increases heart failure risk. This effect remained consistent with multivariable MR. There was also evidence that liability to schizophrenia increases early repolarization risk, largely mediated by BMI and lipid levels. Finally, there was evidence that liability to schizophrenia increases heart rate variability, a direction of effect contrasting previous studies. In the other direction, there was weak evidence that higher systolic, but not diastolic, blood pressure increases schizophrenia risk. Conclusions and relevance: Our findings indicate that liability to schizophrenia increases the risk of heart failure, and that this is not mediated by key health behaviours. This is consistent with the notion that schizophrenia is characterised by a systemic dysregulation of the body (including inflammation and oxidative stress) with detrimental effects on the heart. To decrease cardiovascular mortality among schizophrenia patients, priority should lie with optimal treatment and interventions in early stages of psychoses. We also identified early repolarization, currently understudied, as a potential CVD marker among patients with schizophrenia.

scholarly journals Ethological and Physiological Parameters Assessment in Donkeys Used in Animal Assisted Interventions

Animals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1867
Author(s):  
Michele Panzera ◽  
Daniela Alberghina ◽  
Alessandra Statelli
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Root Mean Square ◽  
Physiological Parameters ◽  
Mean Square ◽  
Objective Indicators ◽  
Selection Of

Background: Few studies have been performed to identify objective indicators for the selection of therapeutic donkeys or to assess their welfare during animal-assisted interventions (AAIs) Objective: This study aimed to evaluate the response to the ethological test and the modifications of physiological parameters in donkeys subjected to AAI sessions. Methods: Thirteen donkeys were subjected to a behavioral evaluation during an AAI session. Heart rate, heart rate variability, and root mean square of successive difference values were detected. Results: Statistically significant changes in the tested parameters were observed during AAI sessions. Conclusions: In donkeys, there was a neurovegetative involvement during AAI sessions. Our data give a contribution to the evaluation of donkey welfare during AAIs.

scholarly journals Effect of moderate physical exercises on the relationship of variability of the heart rhythm with the level of blood pressure and hemodynamic functions in women with essential hypertension

2020 ◽  
pp. 64-73
Author(s):  
Б.И. Кузник ◽  
Ю.Н. Смоляков ◽  
Е.С. Гусева ◽  
С.О. Давыдов ◽  
И.В. Файн
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Blood Flow ◽  
Heart Rate Variability ◽  
Essential Hypertension ◽  
High Frequency ◽  
Low Frequency ◽  
Mean Square ◽  
Positive Correlations ◽  
The Relationship

Цель исследования - выявление взаимосвязи между показателями вариабельности сердечного ритма (ВСР), кровяным давлением и гемодинамическими функциями у женщин, страдающих гипертонической болезнью (ГБ) и находящихся на медикаментозной терапии (ГБ-1), либо в дополнение к этому, проходящих регулярные курсы кинезитерапии (ГБ-2). Методика. Наблюдения проведены на 72 женщинах, страдающих артериальной гипертензией II стадии. В группу ГБ-1 вошли 37 женщин с ГБ, находящихся на медикаментозной терапии, в группу ГБ-2 - 35 женщин с ГБ, которые, помимо медикаментозной терапии, регулярно проходили на протяжении 2-3 лет по 3-4 полуторамесячных курса кинезитерапии (управляемые умеренные физические нагрузки). Для изучения гемодинамики был использован датчик динамического рассеяния света (miniature Dynamic Light Scattering - mDLS) от Elfi-Tech (Rehovot, Israel), измеряющий сигналы, инициированные кожным кровотоком, и использующий методику разложения сигнала на частотные компоненты, связанные с разными гемодинамическими источниками. Из пульсовой компоненты mDLS сигнала извлекалась информация о вариабельности RR-интервалов и рассчитывались индикаторы вариабельности сердечного ритма. Введен показатель «гемодинамический индекс» (Hemodynamic Index - HI). Зависимость HI от скорости сдвига интерпретируется путем сопоставления каждой полосе частот определенной скорости сдвига (HI1 - низкочастотный, HI2 - промежуточный, HI3 - высокочастотный). Использованы следующие относительные (RHI, Relative Hemodynamic Index) и осцилляторные (OHI, Oscillatory Hemodynamic Indexes) гемодинамические индексы: нейрологический (NEUR), Майера (MAYER), дыхательный (RESP) и пульсовой (PULSE). ВСР показатели включали: HR (Heart Rate), PWR (Power) - общую мощность колебаний, LF (Low Frequency), HF (High Frequency), SDNN (Standard Deviation of the Normal-to-Normal), RMSSD (Root Mean Square of the Successive Differences), а также индексы: CVI (Cardiac Vagal Index) и CSI (Cardiac Sympathetic Index). Результаты. У женщин, находящихся исключительно на медикаментозной терапии (ГБ-1), выявляются отрицательные взаимосвязи LF и LF/HF с систолическим, средним и пульсовым давлением. При ГБ-2 проявляются отрицательные связи PWR, LF, HF с пульсовым давлением. При ГБ-1 обнаружены положительные взаимосвязи между HR и гемодинамическими индексами HI1, RHI2 и отрицательная взаимосвязь с RHI3, а также между RMSSD и RHI3 и между HF и HI1/HI3. У пациенток ГБ-2 обнаружена отрицательная корреляция SDNN и RHI1, а также PWR и RHI1; положительные взаимосвязи между PWR и HI2, HI3, RHI2, HF и RHI3 и LF/HF с HI1/HI3; отрицательные связи HF c HI1/HI3 и с RHI1, а также между LF/HF и RHI3, CSI и RHI3. У больных ГБ-1 имеются прямые связи между SDNN, PWR, LF, HF, CVI и NEUR_HI1, что свидетельствует о действии этих факторов на эндотелиальный кровоток (HI1). В группе ГБ-2 установлено наличие лишь положительных связей между LF, HF и NEUR_HI3. У больных ГБ-1 на уровень АД влияют все без исключения осцилляторные ритмы, которые могут оказывать как отрицательное (с MAYER_HI1, PULSE_HI2), так и положительное (MAYER_HI2, RESP_HI3) влияние. У больных ГБ-2 взаимосвязи АД с осцилляторными индексами не обнаружены. Заключение. Уменьшение в группе ГБ-2 по сравнению с больными группы ГБ-1 числа факторов, влияющих на АД и гемодинамику, носит более совершенный и благоприятный характер, что и обеспечивает более быструю и устойчивую нормализацию артериального давления. Aim. To study the relationship between heart rate variability (HRV), blood pressure and hemodynamic functions in women with essential hypertension (EH) receiving a drug therapy alone (EH-1) or in combination with regular courses of kinesitherapy (EH-2). Methods. The study included 72 women with EH. The EH-1 group consisted of 37 women with stage II arterial hypertension. The EH-2 group consisted of 35 women with stage II arterial hypertension who underwent 3-4 1.5-month courses of kinesitherapy (controlled moderate physical activity) on a regular basis for 2-3 years. Hemodynamics was studied with a miniature Dynamic Light Scattering (mDLS) sensor from Elfi-Tech (Rehovot, Israel), which measures signals initiated by the skin blood flow by decomposing the signal into frequency components associated with different hemodynamic sources. Information on the RR interval variability was extracted from the pulse component of mDLS signal, and indicators of heart rate variability were calculated. A Hemodynamic Index (HI) was introduced. The HI dependence on shear rate was interpreted by matching each frequency band with a specific shear rate (HI1, low-frequency; HI2, intermediate; HI3, high-frequency). The following relative (RHI, Relative Hemodynamic Index) and oscillatory (OHI, Oscillatory Hemodynamic Indexes) indexes were used: neurological (NEUR), Mayer (MAYER), respiratory (RESP), and pulse (PULSE) ones. The HRV indexes included HR (Heart Rate), PWR (Power, total oscillation power), LF (Low Frequency), HF (High Frequency), SDNN (Standard Deviation of the Normal-to-Normal), RMSSD (Root Mean Square of the Successive Differences). CVI (Cardiac Vagal Index), and CSI (Cardiac Sympathetic Index). Results. In women who were on drug therapy alone (EH-1), negative relationships were found for LF and LF/HF with systolic, mean and pulse pressure. For EH-2, PWR, LF, and HF negatively correlated with pulse pressure. For EH-1, HR positively correlated with the hemodynamic indices HI1 and RHI2 and negatively correlated with RHI3; RMSSD negatively correlated with RHI3; and HF negatively correlated with HI1/HI3. For patients with EH-2, negative correlations were observed for SDNN and RHI1, PWR and RHI1; positive correlations were found between PWR and HI2; HI3, RHI2, HF and RHI3; and between LF/HF and HI1/HI3. HF negatively correlated with HI1/HI3 and with RHI1. LF/HF negatively correlated with RHI3, and CSI negatively correlated with RHI3. In patients with EH-1, SDNN, PWR, LF, HF, CVI, and NEUR_HI1 were directly related, which indicated an effect of these factors on the endothelial blood flow (HI1). In the EH-2 group, only positive correlations were found between LF, HF, and NEUR_HI3. In EH-1 patients, all oscillatory rhythms influenced BP; this influence could be both negative (for MAYER_HI1, PULSE_HI2) and positive (for MAYER_HI2, RESP_HI3). In EH-2 patients, no relationship was found between blood pressure and oscillatory indices. Conclusion. The smaller number of factors influencing blood pressure and hemodynamics in the EH-2 group compared to the EH-1 group was more beneficial and favorable, which ensured faster and steadier normalization of blood pressure.

scholarly journals Autonomic Imbalance and Risk of Dementia and Stroke

Stroke ◽  
2021 ◽  
Author(s):  
Galit Weinstein ◽  
Kendra Davis-Plourde ◽  
Alexa S. Beiser ◽  
Sudha Seshadri
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Root Mean Square ◽  
Stroke Risk ◽  
Cox Regression ◽  
Mean Square ◽  
Resting Heart Rate ◽  
Autonomic Imbalance ◽  
Dementia Risk

Background and Purpose: The autonomic nervous system has been implicated in stroke and dementia pathophysiology. High resting heart rate and low heart rate variability indicate the effect of autonomic imbalance on the heart. We examined the associations of resting heart rate and heart rate variability with incident stroke and dementia in a community-based cohort of middle- and old-aged adults. Methods: The study sample included 1581 participants aged >60 years and 3271 participants aged >45 years evaluated for incident dementia and stroke, respectively, who participated in the Framingham Offspring cohort third (1983–1987) examination and had follow-up for neurology events after the seventh (1998–2001) examination. Heart rate variability was assessed through the standard deviation (SD) of normal-to-normal RR intervals and the root mean square of successive differences between normal heartbeats from 2-hour Holter monitor. Participants were followed-up for stroke and dementia incidence from exam 7 to a maximum of 10 years. Cox regression models were used to assess the link of resting heart rate and heart rate variability with stroke and dementia risk while adjusting for potential confounders, and interactions with age and sex were assessed. Results: Of the dementia (mean age, 55±6 years, 46% men) and stroke (mean age, 48±9 years, 46% men) samples, 133 and 127 developed dementia and stroke, respectively, during the follow-up. Overall, autonomic imbalance was not associated with dementia risk. However, age modified the associations such that SD of normal-to-normal intervals and root mean square of successive differences were associated with dementia risk in older people (hazard ratio [HR] [95% CI] per 1SD, 0.61 [0.38–0.99] and HR [95% CI] per 1SD, 0.34 [0.15–0.74], respectively). High resting heart rate was associated with increased stroke risk (HR [95% CI] per 10 bpm, 1.18 [1.01–1.39]), and high SD of normal-to-normal intervals was associated with lower stroke risk in men (HR [95% CI] per 1SD, 0.46 [0.26–0.79]) but not women (HR [95% CI] per 1SD, 1.25 [0.88–1.79]; P for interaction=0.003). Conclusions: Some measures of cardiac autonomic imbalance may precede dementia and stroke occurrence, particularly in older ages and men, respectively.

scholarly journals Supercompensation in Elite Water Polo: Heart Rate Variability and Perceived Recovery

2021 ◽  
Vol 5 (02) ◽  
pp. E53-E58
Author(s):  
Petros G. Botonis ◽  
Ilias Smilios ◽  
Argyris G. Toubekis
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Root Mean Square ◽  
Training Load ◽  
Mean Square ◽  
Water Polo ◽  
Similar Association ◽  
Recovery Status

AbstractWe examined the association of heart rate variability assessed with the logarithm of the root mean square of successive differences (LnRMSSD) and perceived recovery status of nine elite water polo players with the fluctuations of the internal training load (ITL). ITL, post-wakening LnRMSSD, and measures of perceived recovery were obtained across one regeneration week, during two mesocycles of intensified preseason training (PR1, PR2) and during two mesocycles of in-season training (IN1, IN2). ITL at PR1 and PR2 was increased by 60–70% compared to regeneration week (p<0.01) and was reduced by 30% at IN1 and IN2 compared to PR1 and PR2 (p<0.01). Weekly averaged LnRMSSD (LnRMSSDmean) was higher in IN2 compared to regeneration week and PR2 (p<0.01 and p<0.05, respectively). Perceived recovery was higher at IN1 and IN2 compared to PR2 (p=0.01 and p<0.001, respectively). ITL correlated with LnRMSSD in the preseason (r=–0.26, p=0.03). Nonetheless, similar association was not apparent during the in-season period (r=0.02, p=0.88). Cardiac autonomic perturbations may not occur when an increment of internal training load is less than 60–70%. However, the reduction of training load in season by 30% improves both LnRMSSDmean and perceived recovery status, implying that training periodization may lead players in supercompensation.

scholarly journals Long-Term Influence of Concussion on Cardio-Autonomic Function in Adolescent Hockey Players

2021 ◽  
Author(s):  
Allyssa K. Memmini ◽  
Michael F. La Fountaine ◽  
Steven P. Broglio ◽  
Robert D. Moore
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Root Mean Square ◽  
Autonomic Function ◽  
Heart Rate Recovery ◽  
Adolescent Male ◽  
Mean Square ◽  
Target Heart Rate ◽  
Concussion History

Context Concussion may negatively influence cardiovascular function and the autonomic nervous system, defined by alteration in heart rate variability (HRV). Differences in HRV most commonly emerge during a physical challenge, such as the final steps of the return-to-sport progression. Objective To assess the effect of concussion history on aspects of cardio-autonomic function during recovery from a bout of submaximal exercise in adolescent male hockey athletes. Design Case-control study. Setting Research laboratory. Patients or Other Participants Thirty-three male athletes participating in Midget-AAA hockey were divided into those with (n = 15; age = 16 ± 1 years, height = 1.78 ± 0.06 m, mass = 73.9 ± 7.4 kg, 10.5 ± 1.6 years of sport experience, 25.2 ± 18.3 months since last injury) or without (n = 18; age = 16 ± 1 years, height = 1.78 ± 0.05 m, mass = 74.8 ± 7.6 kg, 10.6 ± 1.9 years of sport experience) a concussion history. Those with a concussion history were binned on total count: concussion) or 2 or more concussions. Intervention(s) All athletes underwent 5 minutes of resting HRV assessment, followed by 20 minutes of aerobic exercise at 60% to 70% of their maximal target heart rate and a 9-minute, postexercise HRV assessment. Main Outcome Measure(s) Heart rate variability measures of mean NN interval, root mean square of successive differences, and standard deviation of NN interval (SDNN). Results Group demographic characteristics were not different. When the control and concussed groups were compared, group and time main effects for heart rate recovery, root mean square of successive differences, and SDNN (P values &lt; .01), and an interaction effect for SDNN (P &lt; .05) were demonstrated. Recovery trends for each group indicated that a history of 2 or more concussions may negatively affect cardio-autonomic recovery postexercise. Conclusions Our findings suggest that those with more than 1 previous concussion may be associated with a greater risk for long-term dysautonomia. Future use of HRV may provide clinicians with objective guidelines for concussion-management and safe return-to-participation protocols.

scholarly journals Association of Interleukin-6 Signaling and C-Reactive Protein With Intracranial Aneurysm: A Mendelian Randomization and Genetic Correlation Study

2021 ◽  
Vol 12 ◽  
Author(s):  
Peng-Peng Niu ◽  
Xue Wang ◽  
Yu-Ming Xu
Keyword(s):  
Blood Pressure ◽  
Linkage Disequilibrium ◽  
Intracranial Aneurysm ◽  
Genetic Correlation ◽  
Interleukin 6 ◽  
Genome Wide Association Study ◽  
Mendelian Randomization ◽  
Genetic Correlations ◽  
C Reactive Protein ◽  
Reactive Protein

Background and objectiveEvidence suggests that interleukin-6 (IL6) signaling is causally associated with aortic aneurysm independently of the effect of C-reactive protein (CRP). We aimed to explore the genetic overlap and associations between inflammation (IL6 signaling and CRP) and intracranial aneurysm (IA) risk.MethodsTwo-sample Mendelian randomization (MR) methods were used to assess the causal effects of soluble IL6 receptor (sIL6R) (n = 21,758) and CRP (n = 204,402) levels on IA (7,495 cases and 71,934 controls) risk using genome-wide association study summary data of European individuals. Cross-trait linkage disequilibrium score regression was used to estimate the genetic correlations of CRP (n = 400,094) with IA.ResultsMR analyses showed that circulating sIL6R and CRP levels were not associated with the risk of IA. The odds ratios based on the inverse variance-weighted method were 0.986 (0.950–1.023, p = 0.45) and 0.957 (0.846–1.084, p = 0.49) for sIL6R and CRP, respectively. MR analyses using data of ruptured and unruptured IA each showed no association. Linkage disequilibrium score regression showed that the genetic correlation between CRP and IA was 0.16 (SE = 0.04, p = 0.0003). The genetic correlation diminished after conditioning IA on blood pressure (0.07 ± 0.05, p = 0.16), smoking (0.02 ± 0.05, p = 0.65), or blood pressure plus smoking (−0.03 ± 0.05, p = 0.53).ConclusionUsing associated genetic variants as instrument variables, two-sample MR analyses showed no evidence that circulating sIL6R and CRP levels were associated with IA risk. Although a positive genetic correlation was found between CRP levels and IA risk, it was mainly driven by the shared genetic background of blood pressure and smoking with both CRP and IA.

scholarly journals Validity of the ithleteTM Smart Phone Application for Determining Ultra-Short-Term Heart Rate Variability

2013 ◽  
Vol 39 (1) ◽  
pp. 85-92 ◽  
Author(s):  
Andrew A. Flatt ◽  
Michael R. Esco
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Root Mean Square ◽  
Athletic Training ◽  
Smart Phone ◽  
Future Research ◽  
Mean Square ◽  
Short Term ◽  
Current Sample ◽  
Smart Phone Application

Abstract The purpose of this investigation was to cross-validate the ithleteTM heart rate variability smart phone application with an electrocardiograph for determining ultra-short-term root mean square of successive R-R intervals. The root mean square of successive R-R intervals was simultaneously determined via electrocardiograph and ithleteTM at rest in twenty five healthy participants. There were no significant differences between the electrocardiograph and ithleteTM derived root mean square of successive R-R interval values (p > 0.05) and the correlation was near perfect (r = 0.99, p < 0.001). In addition, the ithleteTM revealed a Standard Error of the Estimate of 1.47 and Bland Altman plot showed that the limits of agreement ranged from 2.57 below to 2.63 above the constant error of -0.03. In conclusion, the ithleteTM appeared to provide a suitably accurate measure of root mean square of successive R-R intervals when compared to the electrocardiograph measures obtained in the laboratory within the current sample of healthy adult participants. The current study lays groundwork for future research determining the efficacy of ithleteTM for reflecting athletic training status over a chronic conditioning period.

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