Differences in age-independent effects of blood pressure on baroreflex sensitivity between normal and hypertensive subjects

1986 ◽  
Vol 70 (5) ◽  
pp. 489-494 ◽  
Author(s):  
Kazuyuki Shimada ◽  
Tadao Kitazumi ◽  
Hisakazu Ogura ◽  
Noriko Sadakane ◽  
Toshio Ozawa
Keyword(s):  
Blood Pressure ◽  
Systolic Blood Pressure ◽  
Baroreflex Sensitivity ◽  
Blood Pressure Level ◽  
Normal Subjects ◽  
Inhibitory Effect ◽  
Valsalva Manoeuvre ◽  
Sensitivity Index ◽  
Baroreflex Function ◽  
Age Related

1. Inter-relationship between age, systolic blood pressure and baroreflex sensitivity index derived from the Valsalva manoeuvre was investigated in either combined or separated groups of normal and hypertensive subjects. 2. Both in the total population as a whole and in each blood pressure subgroup, the baroreflex sensitivity index was significantly inversely related to age and to systolic blood pressure. Furthermore, age was significantly related to systolic blood pressure except in the hypertensive group. 3. Partial correlation analysis showed that, in the total and hypertensive population, the baroreflex sensitivity index was significantly related to age and systolic blood pressure independently of each other variable. In the normal group, however, the baroreflex sensitivity index was not related to systolic blood pressure after adjusting for the effect of age, but remained significantly related to age independently of systolic blood pressure. The estimates of relative effects of the two variables on baroreflex sensitivity by multiple regression analysis were consistent with these results. 4. Thus a prevailing concept of the inhibitory effect of blood pressure on baroreflex function may be accurate exclusively in hypertensive patients, and baroreflex function appears to be more sensitive to age-related changes in this system than to those related to blood pressure level, particularly in non-hypertensive normal subjects.

scholarly journals Development of Causal Interactions Between Systolic Blood Pressure and Inter-Beat Intervals in Adolescents

2015 ◽  
pp. 821-829 ◽  
Author(s):  
J. SVAČINOVÁ ◽  
M. JAVORKA ◽  
Z. NOVÁKOVÁ ◽  
E. ZÁVODNÁ ◽  
B. CZIPPELOVÁ ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Systolic Blood Pressure ◽  
Healthy Subjects ◽  
Baroreflex Sensitivity ◽  
Closed Loop ◽  
Loop Model ◽  
Bivariate Model ◽  
Causal Pathways ◽  
Linear Approach ◽  
Age Related

Systolic blood pressure (SBP) changes control the cardiac inter-beat intervals (IBI) duration via baroreflex. Conversely, SBP is influenced by IBI via non-baroreflex mechanisms. Both causal pathways (feedback – baroreflex and feedforward – non-baroreflex) form a closed loop of the SBP – IBI interaction. The aim of this study was to assess the age-related changes in the IBI – SBP interaction. We have non-invasively recorded resting beat-to-beat SBP and IBI in 335 healthy subjects of different age, ranging from 11 to 23 years. Using a linear autoregressive bivariate model we obtained gain (GainSBP,IBI, used traditionally as baroreflex sensitivity) and coherence (CohSBP,IBI) of the SBP–IBI interaction and causal gain and coherence in baroreflex (GainSBPIBI, CohSBPIBI) and coherence in non-baroreflex (CohIBISBP) directions separately. A non-linear approach was used for causal coupling indices evaluation (CSBPIBI, CIBISBP) quantifying the amount of information transferred between signals. We performed a correlation to age analysis of all measures. CohIBISBP and CIBISBP were higher than CohSBPIBI and CSBPIBI, respectively. GainSBP,IBI increased and CohSBPIBI decreased with age. The coupling indices did not correlate with age. We conclude that the feedforward influence dominated at rest. The increase of GainSBP,IBI with age was not found in the closed loop model. A decrease of CohSBPIBI could be related to a change in the cardiovascular control system complexity during maturation.

Effect of heavy exercise on spectral baroreflex sensitivity, heart rate, and blood pressure variability in well-trained humans

2008 ◽  
Vol 295 (3) ◽  
pp. H1150-H1155 ◽  
Author(s):  
François Cottin ◽  
Claire Médigue ◽  
Yves Papelier
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Systolic Blood Pressure ◽  
Exercise Test ◽  
Blood Pressure Variability ◽  
Baroreflex Sensitivity ◽  
Low Frequency ◽  
Mechanical Effect ◽  
Heavy Exercise ◽  
Gas Exchange Parameters

The aim of the study was to assess the instantaneous spectral components of heart rate variability (HRV) and systolic blood pressure variability (SBPV) and determine the low-frequency (LF) and high-frequency baroreflex sensitivity (HF-BRS) during a graded maximal exercise test. The first hypothesis was that the hyperpnea elicited by heavy exercise could entail a significant increase in HF-SBPV by mechanical effect once the first and second ventilatory thresholds (VTs) were exceeded. It was secondly hypothesized that vagal tone progressively withdrawing with increasing load, HF-BRS could decrease during the exercise test. Fifteen well-trained subjects participated in this study. Electrocardiogram (ECG), blood pressure, and gas exchanges were recorded during a cycloergometer test. Ventilatory equivalents were computed from gas exchange parameters to assess VTs. Spectral analysis was applied on cardiovascular series to compute RR and systolic blood pressure power spectral densities, cross-spectral coherence, gain, and α index of BRS. Three exercise intensity stages were compared: below (A1), between (A2), and above (A3) VTs. From A1 to A3, both HF-SBPV (A1: 45 ± 6, A2: 65 ± 10, and A3: 120 ± 23 mm2Hg, P < 0.001) and HF-HRV increased (A1: 20 ± 5, A2: 23 ± 8, and A3:40 ± 11 ms2, P < 0.02), maintaining HF-BRS (gain, A1: 0.68 ± 0.12, A2: 0.63 ± 0.08, and A3: 0.57 ± 0.09; α index, A1: 0.58 ± 0.08, A2: 0.48 ± 0.06, and A3: 0.50 ± 0.09 ms/mmHg, not significant). However, LF-BRS decreased (gain, A1: 0.39 ± 0.06, A2: 0.17 ± 0.02, and A3: 0.11 ± 0.01, P < 0.001; α index, A1: 0.46 ± 0.07, A2: 0.20 ± 0.02, and A3: 0.14 ± 0.01 ms/mmHg, P < 0.001). As expected, once VTs were exceeded, hyperpnea induced a marked increase in both HF-HRV and HF-SBPV. However, this concomitant increase allowed the maintenance of HF-BRS, presumably by a mechanoelectric feedback mechanism.

Differences in Blood Pressure Level and Hypertension in Three Ethnic Groups of Northeastern India

2000 ◽  
Vol 12 (2) ◽  
pp. 71-78 ◽  
Author(s):  
N.C. Hazarika ◽  
D. Biswas ◽  
K. Narain ◽  
R.K. Phukan ◽  
H.C. Kalita ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Body Mass Index ◽  
Waist Circumference ◽  
Systolic Blood Pressure ◽  
Diastolic Blood Pressure ◽  
Ethnic Groups ◽  
Body Mass ◽  
Alcohol Intake ◽  
Blood Pressure Level ◽  
Tea Garden

A cross sectional study on hypertension was done on 294 subjects aged 30 years and above. 150 households were selected randomly representing 50 households from each locality inhabited exclusively by the rural Mizos, indigenous rural Assamese and the tea-garden workers respectively, in the northeastern region of India. Blood pressure was measured by sphygmo-manorneter in sitting posture. Anthro-pometric measurements were taken using standard procedure for measuring height, weight, waist and hip girth. Information on age, sex, ethnicity, literacy, alcohol intake, smoking pattern, physical activity, occupation, amount of salt consumption was collected using a standard and pre-tested questionnaire. Significant differences were observed in both the systolic and diastolic blood pressure levels among the three different ethnic groups selected for this study ( p<0.0001). Multiple regression analyses indicated that in Mizos, age, waist circumference and alcohol intake were independently associated with increase in systolic blood pressure whereas smoking was found to be negatively associated with systolic blood pressure ( R2=0.391, p<0.001). Factors, which were the best predictors of diastolic blood pressure, were age and body mass index [(kg/m2) ( R2=0.227, p<0.001)]. In the rural Assamese population, the best predictors of systolic blood pressure were age and waist circumference ( R2=0.263, p=0.018). For the diastolic blood pressure, age, alcohol intake and body mass index were important correlates ( R2 = 0.131, p<0.001). In the tea garden community, important predictors of systolic blood pressure were age, gender and marital status ( R2=0.187, p<0.001). On the other hand, age and alcohol intake were best predictors for diastolic blood pressure ( R2=0.09, p<0.001). Asia Pac J Public Health 2000,-12(2): 71-78

The Rate of Increase in Blood Pressure in Children 5 Years of Age Is Related to Changes in Aerobic Fitness and Body Mass Index

PEDIATRICS ◽  
1994 ◽  
Vol 94 (4) ◽  
pp. 465-470
Author(s):  
Steven Shea ◽  
Charles E. Basch ◽  
Bernard Gutin ◽  
Aryeh D. Stein ◽  
Isobel R. Contento ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Body Mass Index ◽  
Systolic Blood Pressure ◽  
Diastolic Blood Pressure ◽  
Body Mass ◽  
Aerobic Fitness ◽  
Medical Center ◽  
Multiple Regression Model ◽  
Age Related ◽  
Rate Of Increase

Objective. To determine whether changes in aerobic fitness and body mass index are related to the age-related rise in blood pressure in healthy preschool children. Study design. Longitudinal analyses of 196 free-living children aged 5 years at baseline who were followed over a mean of 19:7 months. Aerobic fitness was assessed using a treadmill All measures were obtained on multiple occasions at scheduled visits as part of a longitudinal cohort study. Setting. An inner-city medical center. Outcome measures. Blood pressure was measured using an automated Dinamap device. Results. Mean systolic blood pressure was 95.3 mmHg (SD 8.38) at baseline and increased by 4.46 mmHg per year. Mean diastolic blood pressure was 53.9 mmHg (SD 5.81) at baseline and did not change significantly. Children in the highest quintile of increase in fitness had a significantly smaller increase in systolic blood pressure compared to children in the lowest quintile (2.92 vs 5.10 mmHg/year; P = .03). Children in the lowest quintile of increase in body mass index did not differ significantly in rate of increase in systolic blood pressure compared to children in the highest quintile (3.92 vs 4.96 mmHg/year). In a multiple regression model including baseline systolic blood pressure, fitness, height, body mass index, and other covariates, greater increase in fitness (P = .03) and lesser increase in body mass index (P &lt; .01) were associated with lower rates of increase in systolic blood pressure. In a similar multivariate analysis, an increase in fitness was also associated with a lower rate of increase in diastolic blood pressure (P = .02) Conclusion. Young children who increase their aerobic fitness or decrease their body mass index reduce the rate of the age-related increase in blood pressure. These observations may have implications for development of interventions directed at the primary prevention of hypertension.

Assessing Children's Blood Pressure—Considerations of Age and Body Size: The Muscatine Study

PEDIATRICS ◽  
1985 ◽  
Vol 75 (6) ◽  
pp. 1081-1090
Author(s):  
Ronald M. Lauer ◽  
Trudy L. Burns ◽  
William R. Clarke
Keyword(s):  
Blood Pressure ◽  
Body Weight ◽  
Body Size ◽  
Systolic Blood Pressure ◽  
High Blood Pressure ◽  
Clinical Setting ◽  
Blood Pressure Level ◽  
Pressure Level ◽  
Excessive Body Weight

Blood pressure was assessed in 4,207 children, aged 5 to 18 years, examined in the schools of Muscatine, Iowa during 1981. Overall, 69.9% of the age-sex-specific quintiles and height-sex-specific quintiles of systolic blood pressure were identical. In only 1.0% of children did these quintiles differ by more than one. Children whose blood pressure was in the highest quintile for both age and height were more obese than their peers. Those whose blood pressure was high for age but not for height were proportionately taller and heavier than their age peers. Children whose blood pressure was high for height but not for age were older, shorter, and lighter. Thus, having precocious levels of blood pressure for age during childhood is associated with excessive body weight or precocious height, whereas having high blood pressure for height but not for age is associated with being short for age. The latter suggests that age may be a factor independent of height and weight affecting blood pressure level in childhood. These relationships of body size and age to blood pressure must be considered when evaluating children's blood pressure levels in the clinical setting, and a technique for doing so is presented.

Effects of Aging on the Variability of Arterial Pressure in Essential Hypertensive Patients

1982 ◽  
Vol 63 (s8) ◽  
pp. 411s-414s ◽  
Author(s):  
Jun Ogawa ◽  
Shigeo Takata ◽  
Gakuji Nomura ◽  
Shiro Arai ◽  
Takayuki Ikeda ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Stroke Volume ◽  
Systolic Blood Pressure ◽  
Diastolic Blood Pressure ◽  
Pulse Pressure ◽  
Baroreflex Sensitivity ◽  
Peripheral Resistance ◽  
Resistance Index ◽  
Average Systolic Blood Pressure ◽  
Effects Of Aging

1. We studied the effects of aging on the variability of blood pressure in mild to moderate essential hypertensive subjects. 2. Cardiac index was greater and total peripheral resistance index was less in patients under 40 years (by an average of 1.06 litres min−1 m−2 and 9.23 mmHg 1−1 min−1 m−2) than in those over 40 respectively (P < 0.001 for each). 3. Pulse pressure/stroke volume was less by an average of 0.345 mmHg/ml in patients under 40 years than that in those over 40 (P < 0.001). Pulse pressure/stroke volume was correlated with age (r = 0.621), average systolic blood pressure (r = 0.623) and inversely with baroreflex sensitivity (r = −0.494). 4. Baroreflex sensitivity was less by an average of 3.1 ms/mmHg in patients over 30 years than in those under 30 (P < 0.025). Baroreflex sensitivity was inversely correlated with age (r = −0.617) and average systolic blood pressure (r = −0.589). 5. Beat by beat variability of systolic blood pressure was correlated with age (r = 0.460), particularly when the data of those in their twenties were excluded (r = 0.618), and significantly with pulse pressure/stroke volume (r = 0.650), average systolic blood pressure (r = 0.618) and inversely with baroreflex sensitivity (r = −0.477). These relationships were not observed for diastolic blood pressure. 6. Maximum difference in systolic blood pressure in a day was correlated with pulse pressure/stroke volume (r = 0.482) and average systolic blood pressure (r = 0.648) but not with baroreflex sensitivity. These relationships were not observed for diastolic blood pressure. 7. Variability of systolic blood pressure in patients over 30 years gradually increased with age. In contrast, those of systolic and diastolic blood pressures in subjects in their twenties were relatively large. This might be related to factors other than aging, presumably those which underlie the hyperdynamic circulatory state.

A New Non-Invasive Statistical Method to Assess the Spontaneous Cardiac Baroreflex in Humans

1995 ◽  
Vol 88 (6) ◽  
pp. 651-655 ◽  
Author(s):  
Michel Ducher ◽  
Jean Pierre Fauvel ◽  
Marie Paule Gustin ◽  
Catherine Cerutti ◽  
Robert Najem ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Systolic Blood Pressure ◽  
Spectrum Analysis ◽  
Baroreflex Sensitivity ◽  
Correlation Coefficients ◽  
Statistical Dependence ◽  
High Systolic Blood Pressure ◽  
Cross Spectrum ◽  
The Cross

1. A new method was developed to evaluate cardiac baroreflex sensitivity. The association of a high systolic blood pressure with a low heart rate or the converse is considered to be under the influence of cardiac baroreflex activity. This method is based on the determination of the statistical dependence between systolic blood pressure and heart rate values obtained non-invasively by a Finapres device. Our computerized analysis selects the associations with the highest statistical dependence. A ‘Z-coefficient’ quantifies the strength of the statistical dependence. The slope of the linear regression, computed on these selected associations, is used to estimate baroreflex sensitivity. 2. The present study was carried out in 11 healthy resting male subjects. The results obtained by the ‘Z-coefficient’ method were compared with those obtained by cross-spectrum analysis, which has already been validated in humans. Furthermore, the reproducibility of both methods was checked after 1 week. 3. The results obtained by the two methods were significantly correlated (r = 0.78 for the first and r = 0.76 for the second experiment, P < 0.01). When repeated after 1 week, the average results were not significantly different. Considering individual results, test—retest correlation coefficients were higher with the Z-analysis (r = 0.79, P < 0.01) than with the cross-spectrum analysis (r = 0.61, P < 0.05). 4. In conclusion, as the Z-method gives results similar to but more reproducible than the cross-spectrum method, it might be a powerful and reliable tool to assess baroreflex sensitivity in humans.

Ascorbic acid increases cardiovagal baroreflex sensitivity in healthy older men

2004 ◽  
Vol 286 (6) ◽  
pp. H2113-H2117 ◽  
Author(s):  
Kevin D. Monahan ◽  
Iratxe Eskurza ◽  
Douglas R. Seals
Keyword(s):  
Oxidative Stress ◽  
Blood Pressure ◽  
Ascorbic Acid ◽  
Systolic Blood Pressure ◽  
Sodium Nitroprusside ◽  
Baroreflex Sensitivity ◽  
Older Men ◽  
Acid Infusion ◽  
Healthy Men ◽  
Phenylephrine Hydrochloride

Cardiovagal baroreflex sensitivity (BRS) declines with advancing age in healthy men. We tested the hypothesis that oxidative stress contributes mechanistically to this age-associated reduction. Eight young (23 ± 1 yrs, means ± SE) and seven older (63 ± 3) healthy men were studied. Cardiovagal BRS was assessed using the modified Oxford technique (bolus infusion of 50–100 μg sodium nitroprusside, followed 60 s later by a 100- to 150-μg bolus of phenylephrine hydrochloride) in triplicate at baseline and during acute intravenous ascorbic acid infusion. At baseline, cardiovagal BRS (slope of the linear portion of the R-R interval-systolic blood pressure relation during pharmacological changes in arterial blood pressure) was 56% lower ( P < 0.01) in older (8.3 ± 1.6 ms/mmHg) compared with young (19.0 ± 3.1 ms/mmHg) men. Ascorbic acid infusion increased plasma concentrations similarly in young (62 ± 9 vs. 1,249 ± 72 μmol/l for baseline and during ascorbic acid; P < 0.05) and older men (62 ± 4 vs. 1,022 ± 55 μmol/l; P < 0.05) without affecting baseline blood pressure, heart rate, carotid artery compliance, or the magnitude of change in systolic blood pressure in response to bolus sodium nitroprusside and phenylephrine hydrochloride infusion. Ascorbic acid (vitamin C) infusion increased cardiovagal BRS in older (Δ58 ± 16%; P < 0.01), but not younger (Δ − 4 ± 4%) men. These data provide experimental support for the concept that oxidative stress contributes mechanistically to age-associated reductions in cardiovagal BRS in healthy men.

Loneliness is a unique predictor of age-related differences in systolic blood pressure.

2006 ◽  
Vol 21 (1) ◽  
pp. 152-164 ◽  
Author(s):  
Louise C. Hawkley ◽  
Christopher M. Masi ◽  
Jarett D. Berry ◽  
John T. Cacioppo
Keyword(s):  
Blood Pressure ◽  
Systolic Blood Pressure ◽  
Age Related ◽  
Unique Predictor
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