Exaggerated blood pressure response to exercise is associated with subclinical vascular impairment in healthy normotensive individuals

Blood pressure response during exercise testing in individuals with and without hypertension: The value of the recovery phase

BACKGROUND

Hypertension and exercise testing are essential for cardiovascular risk assessment. However, an exact description of blood pressure (BP) in patients with a hypertensive response during exercise (HRE), especially in the recovery phase is lacking. Herein, we aimed to analyse BP and heart rate during exercise testing and recovery in patients with an HRE.

METHODS

800 patients aged 17-90 with an HRE during a standardized bicycle ergometry test were recruited. The BP behaviour during exercise testing was correlated with clinical data. Furthermore, data were analysed according to the presence of pre-existent hypertension.

RESULTS

Of the 800 patients included in this study 497 (62%) were previously diagnosed with hypertension. Analysis of covariance showed a significantly faster systolic (β [95% CI] 8.0 [4.9-11.1]) and diastolic (2.4 [0.4-4.4]) BP recovery 3 min after maximal exercise in patients without hypertension in univariable models. These results remained robust in fully adjusted models taking into account age, sex, body mass index, cardiovascular disease, and antihypertensive treatment for systolic (5.3 [1.2-9.4]) and diastolic BP (4.5 [1.9-7.0]). Furthermore, patients with hypertension displayed higher systolic BP during maximal exercise in univariable (3.8 [0.1-7.5]) and fully adjusted (5.5 [1.1-10.0]) models. There was no difference in maximum diastolic BP between groups.

CONCLUSION

In this large cohort study, patients without hypertension showed a faster systolic and diastolic BP recovery and lower maximal systolic BP compared to patients with hypertension. Overall, this study provides new insights into cardiovascular health during recovery phase.

Usability of myocardial work parameters to demonstrate subclinical myocardial involvement in normotensive individuals with exaggerated hypertensive response in treadmill exercise testing

Early determination of changes in myocardial functions is essential for the protection of cardiovascular diseases. This study aimed to evaluate myocardial work parameters in healthy individuals who developed an exaggerated hypertensive response during the treadmill exercise test procedure. The study included a total of 64 patients for whom an exercise electrocardiography test was planned for functional capacity evaluation. The study population was divided according to the presence of exaggerated hypertensive response to exercise (EBPRE) (SBP/DBP ≥210/105 mmHg in males ≥190/105 mmHg in females) and normal blood pressure response to exercise (NBPRE). Patients' echocardiographic evaluations were made at rest, and myocardial work parameters were calculated. There was no statistical difference between the groups (NBPRE vs. EBPRE, respectively) in terms of left ventricular 2,3 and 4 chamber strains and global longitudinal strain (GLS) values (-20.6 ± -2.3, -19.7 ± -1.9, p:.13; -21.3 ± -2.7, -21 ± -2.4, p:.68; -21.2 ± -2.2, -21.2 ± -2.3, p:.93; and -20.8 ± -1.5, -20.4 ± -1.5, p:.23, respectively). Global constrictive work (GCW), global waste work (GWW), and global work efficiency (GWE) were not statistically different between the two groups (2374 ± 210, 2465 ± 204, p:.10; 142 ± 64, 127 ± 42, p:.31; 94.3 ± 2.5, 95.1 ± 1.5, p:.18, respectively). In contrast, global work index (GWI) parameters were different between the two groups (2036 ± 149, 2147 ± 150, p < .001). The GWI was independently associated with EBPRE (odds ratio with 95% 3.32 (1.02-11.24), p = .03). The partial effect plots were used for GWI to predict EBPRE, according to the results, an increase in GWI predicts probability of exaggerated hypertensive response. In conclusion, Myocardial work analyses might be used to identify early signs of myocardial involvement in normotensive patients with EBPRE.

Association of central blood pressure with an exaggerated blood pressure response to exercise among elite athletes

PURPOSE

The systolic blood pressure/workload (SBP/MET) slope was recently reported to be a reliable parameter to identify an exaggerated blood pressure response (eBPR) in the normal population and in athletes. However, it is unclear whether an eBPR correlates with central blood pressure (CBP) and vascular function in elite athletes.

METHODS

We examined 618 healthy male elite athletes (age 25.8 ± 5.1 years) of mixed sports with a standardized maximum exercise test. CBP and vascular function were measured non-invasively with a validated oscillometric device. The SBP/MET slope was calculated and the threshold for an eBPR was set at > 6.2 mmHg/MET. Two groups were defined according to ≤ 6.2 and > 6.2 mmHg/MET, and associations of CBP and vascular function with the SBP/MET slope were compared for each group.

RESULTS

Athletes with an eBPR (n = 180, 29%) displayed a significantly higher systolic CBP (102.9 ± 7.5 vs. 100 ± 7.7 mmHg, p = 0.001) but a lower absolute (295 ± 58 vs. 384 ± 68 W, p < 0.001) and relative workload (3.14 ± 0.54 vs. 4.27 ± 1.1 W/kg, p < 0.001) compared with athletes with a normal SBP/MET slope (n = 438, 71%). Systolic CBP was positively associated with the SBP/MET slope (r = 0.243, p < 0.001). In multiple logistic regression analyses, systolic CBP (odds ratio [OR] 1.099, 95% confidence interval [CI] 1.045-1.155, p < 0.001) and left atrial volume index (LAVI) (OR 1.282, CI 1.095-1.501, p = 0.002) were independent predictors of an eBPR.

CONCLUSION

Systolic CBP and LAVI were independent predictors of an eBPR. An eBPR was further associated with a lower performance level, highlighting the influence of vascular function on the BPR and performance of male elite athletes.

Effects of reduced sedentary time on resting, exercise and post-exercise blood pressure in inactive adults with metabolic syndrome - a six-month exploratory RCT

Evidence on the long-term effects of reducing sedentary behaviour (SB) on blood pressure (BP) is scarce. Therefore, we performed a sub-analysis of the BP effects of a six-month intervention that aimed at reducing SB by 1 h/day and replacing it with non-exercise activities. Sixty-four physically inactive and sedentary adults with metabolic syndrome (58% female, 58 [SD 7] years, BP 143/88 [16/9] mmHg, SB 10 [1] h/day) were randomised into intervention (INT, n = 33) and control (CON, n = 31) groups. Resting BP and BP at each stage during and after a graded maximal bicycle ergometer test were measured before and after the intervention. SB, standing, moderate-to-vigorous physical activity (MVPA), and light physical activity (LPA) were measured in six-second intervals at baseline and during the whole six-month intervention using hip-worn accelerometers. The analyses were adjusted for BP medication status. The intervention resulted in a 40 min/day reduction in SB and concomitant 20 min/day increase in MVPA. Resting systolic BP was lower in the CON group before and after the intervention. No group x time interactions were observed in resting BP or BP during exercise at submaximal or maximal intensities, or during recovery. The changes in LPA and MVPA were inversely correlated with the changes in BP during light-to-moderate intensity exercise. An intervention that resulted in a 40 min/day reduction in SB for six months was not sufficient at influencing BP at rest, during or after exercise in adults with metabolic syndrome. However, successfully increasing LPA or MVPA might lower BP during light-to-moderate-intensity activities.

CAVI (Cardio-Ankle Vascular Index) as an independent predictor of hypertensive response to exercise

OBJECTIVES

Hypertensive response to exercise (HRE) is related to the development of future hypertension, cardiovascular morbidity, and mortality, independent of resting blood pressure. We hypothesized that arterial stiffness as measured by cardio-ankle vascular index (CAVI) could be an independent predictor of HRE.

MATERIALS AND METHODS

Retrospective chart review of patients participated in the preventive health program at the Bangkok Heart Hospital who underwent both CAVI and treadmill stress testing on the same day between June and December 2018 were performed. Variables for the prediction of HRE were analyzed using univariate analysis, and significant variables were entered into multiple logistic regression. An ROC curve was created to test the sensitivity and specificity of CAVI as a predictor of HRE.

RESULTS

A total of 285 participants (55.1% female) were enrolled in this study. There were 58 patients (20.4%) who met the HRE definition (SBP > 210 mmHg in males, SBP > 190 mmHg in females, or DBP > 110 mmHg in both males and females), with a mean age of 46.4 12.8 years. In univariate analysis, age, systolic blood pressure at rest, diastolic blood pressure at rest, pulse pressure at rest, diabetes mellitus, hypertension, dyslipidemia, history of beta-blocker, and CAVI results were statistically significant. Multiple logistic regression revealed that CAVI and systolic blood pressure were statistically significant predictors of HRE with OR of 5.8, 95%CI: 2.9-11.7, P < 0.001 and OR 1.07, 95%CI: 1.03-1.10, P = 0.001 respectively. ROC curve analysis of the CAVI revealed an AUC of 0.827 (95%CI: 0.76-0.89, p < 0.001), and the sensitivity and specificity of cut-point CAVI > 8 were 53% and 92%, respectively.

CONCLUSION

This study demonstrated that CAVI is an independent predictor of hypertensive response to exercise. Additionally, the findings suggest that CAVI > 8 can be a valuable tool in identifying individuals at risk for hypertensive responses during exercise.

Aortic stiffness contributes to greater pressor responses during static hand grip exercise in healthy young and middle-aged normotensive men

Central arterial stiffness can influence exercise blood pressure (BP) by increasing the rise in arterial pressure per unit increase in aortic inflow. Whether central arterial stiffness influences the pressor response to isometric handgrip exercise (HG) and post-exercise muscle ischemia (PEMI), two common laboratory tests to study sympathetic control of BP, is unknown. We studied 46 healthy non-hypertensive males (23 young and 23 middle-aged) during HG (which increases in cardiac output [Q̇c]) and isolated metaboreflex activation PEMI (no change or decreases in Q̇c). Aortic stiffness (aortic pulse wave velocity [aPWV]; applanation tonometry via SphygmoCor) was measured during supine rest and was correlated to the pressor responses to HG and PEMI. BP (photoplethysmography) and muscle sympathetic nerve activity (MSNA) were continuously recorded at rest, during HG to fatigue (35 % maximal voluntary contraction) and 2-min of PEMI. aPWV was higher in middle-aged compared to young males (7.1 ± 0.9 vs 5.4 ± 0.7 m/s, P < 0.001). Middle-aged males also exhibited greater increases in systolic pressure (∆30 ± 11 vs 10 ± 8 mmHg) and MSNA (∆2313 ± 2006 vs 1387 ± 1482 %/min) compared to young males during HG (both, P < 0.03); with no difference in the Q̇c response (P = 0.090). Responses to PEMI were not different between groups. Sympathetic transduction during these stressors (MSNA-diastolic pressure slope) was not different between groups (P > 0.341). Middle-aged males displayed a greater increase in SBP per unit change of Q̇c during HG (∆SBP/∆Q̇c; 21 ± 18 vs 6 ± 10 mmHg/L/min, P = 0.004), with a strong and moderate relationship between the change in systolic (r = 0.53, P < 0.001) and diastolic pressure (r = 0.34, P = 0.023) and resting aPWV, respectively; with no correlation during PEMI. Central arterial stiffness can modulate pressor responses during stimuli associated with increases in cardiac output and sympathoexcitation in healthy males.

Masked Hypertension and Exaggerated Blood Pressure Response to Exercise: A Review and Meta-Analysis

Aim: Whether exaggerated blood pressure response (EBPR) to exercise represents a marker of masked hypertension (MH) in individuals with no prior history of hypertension is still unclear. We investigated this issue through a review and a meta-analysis of studies providing data on this association in normotensive individuals undergone both to dynamic or static exercise and to 24 h blood pressure monitoring (ABPM). Design: A systematic search was performed using Pub-Med, OVID, EMBASE, and Cochrane library databases from inception up to 31 December 2022. Studies were identified by using the following search terms: “masked hypertension”, “out-of-office hypertension”, “exercise blood pressure”, “exaggerated blood pressure exercise”, “exercise hypertension”. Results: Nine studies including a total of 387 participants with MH and 406 true normotensive controls were considered. Systolic BP (SBP) and diastolic BP (DBP) at rest were significantly higher in MH individuals than in sustained normotensives: 126.4 ± 1.4/78.5 ± 1.8 versus 124.0 ± 1.4/76.3 ± 1.3 mmHg (SMD: 0.21 ± 0.08, CI: 0.06–0.37, p = 0.007 for SBP; 0.24 ± 0.07, CI: 0.08–0.39, p = 0.002 for DBP). The same was true for BP values at peak exercise: 190.0 ± 9.5/96.8 ± 3.7 versus 173.3 ± 11.0/88.5 ± 1.8 mmHg (SMD 1.02 ± 0.32, CI: 0.39–1.65, p = 0.002 for SBP and 0.97 ± 0.25, CI: 0.47–1.96, p < 0.0001 for DBP). The likelihood of having an EBPR was significantly greater in MH than in their normotensive counterparts (OR: 3.33, CI: 1.83–6.03, p < 0.0001). Conclusions: Our meta-analysis suggests that EBPR reflects an increased risk of MH and that BP measurement during physical exercise aimed to assess cardiovascular health may unmask the presence of MH. This underscores the importance of BP measured in the medical setting at rest and in dynamic conditions in order to identify individuals at high cardiovascular risk due to unrecognized hypertension.

Blood Pressure Response and Pulse Arrival Time During Exercise Testing in Well-Trained Individuals

Introduction: There is a lack of data describing the blood pressure response (BPR) in well-trained individuals. In addition, continuous bio-signal measurements are increasingly investigated to overcome the limitations of intermittent cuff-based BP measurements during exercise testing. Thus, the present study aimed to assess the BPR in well-trained individuals during a cycle ergometer test with a particular focus on the systolic BP (SBP) and to investigate pulse arrival time (PAT) as a continuous surrogate for SBP during exercise testing.

Materials and Methods: Eighteen well-trained male cyclists were included (32.4 ± 9.4 years; maximal oxygen uptake 63 ± 10 ml/min/kg) and performed a stepwise lactate threshold test with 5-minute stages, followed by a continuous test to voluntary exhaustion with 1-min increments when cycling on an ergometer. BP was measured with a standard automated exercise BP cuff. PAT was measured continuously with a non-invasive physiological measurements device (IsenseU) and metabolic consumption was measured continuously during both tests.

Results: At lactate threshold (281 ± 56 W) and maximal intensity test (403 ± 61 W), SBP increased from resting values of 136 ± 9 mmHg to maximal values of 219 ± 21 mmHg and 231 ± 18 mmHg, respectively. Linear within-participant regression lines between PAT and SBP showed a mean r² of 0.81 ± 17.

Conclusion: In the present study focusing on the BPR in well-trained individuals, we observed a more exaggerated systolic BPR than in comparable recent studies. Future research should follow up on these findings to clarify the clinical implications of the high BPR in well-trained individuals. In addition, PAT showed strong intra-individual associations, indicating potential use as a surrogate SBP measurement during exercise testing.

Is Sleep Disordered Breathing Confounding Rehabilitation Outcomes in Spinal Cord Injury Research?

The purpose of this article is to highlight the importance of considering sleep-disordered breathing (SDB) as a potential confounder to rehabilitation research interventions in spinal cord injury (SCI). SDB is highly prevalent in SCI, with increased prevalence in individuals with higher and more severe lesions, and the criterion standard treatment with continuous positive airway pressure remains problematic. Despite its high prevalence, SDB is often untested and untreated in individuals with SCI. In individuals without SCI, SDB is known to negatively affect physical function and many of the physiological systems that negatively affect physical rehabilitation in SCI. Thus, owing to the high prevalence, under testing, low treatment adherence, and known negative effect on the physical function, it is contended that underdiagnosed SDB in SCI may be confounding physical rehabilitation research studies in individuals with SCI. Studies investigating the effect of treating SDB and its effect on physical rehabilitation in SCI were unable to be located. Thus, studies investigating the likely integrated relationship among physical rehabilitation, SDB, and proper treatment of SDB in SCI are needed. Owing to rapid growth in both sleep medicine and physical rehabilitation intervention research in SCI, the authors contend it is the appropriate time to begin the conversations and collaborations between these fields. We discuss a general overview of SDB and physical training modalities, as well as how SDB could be affecting these studies.

Inorganic nitrate attenuates cardiac dysfunction: role for xanthine oxidoreductase and nitric oxide

Nitric oxide (NO) is a vasodilator and independent modulator of cardiac remodelling. Commonly, in cardiac disease (e.g. heart failure) endothelial dysfunction (synonymous with NO-deficiency) has been implicated in increased blood pressure (BP), cardiac hypertrophy and fibrosis. Currently no effective therapies replacing NO have succeeded in the clinic. Inorganic nitrate (NO₃ ^- ), through chemical reduction to nitrite and then NO, exerts potent BP-lowering but whether it might be useful in treating undesirable cardiac remodelling is unknown. In a nested age- and sex-matched case-control study of hypertensive patients +/- left ventricular hypertrophy (NCT03088514) we show that lower plasma nitrite concentration and vascular dysfunction accompany cardiac hypertrophy and fibrosis in patients. In mouse models of cardiac remodelling, we also show that restoration of circulating nitrite levels using dietary nitrate improves endothelial dysfunction through targeting of xanthine oxidoreductase (XOR)-driven H₂ O₂ and superoxide, and reduces cardiac fibrosis through NO-mediated block of SMAD-phosphorylation leading to improvements in cardiac structure and function. We show that via these mechanisms dietary nitrate offers easily translatable therapeutic options for treatment of cardiac dysfunction.

A Randomized Crossover Trial on the Acute Cardiovascular Demands During Flywheel Exercise

In a randomized crossover trial, we examined whether age plays a role in the mean arterial pressure (MAP) response during a vigorous flywheel exercise of varying load. We hypothesized that the magnitude of increase in the MAP during the flywheel exercise would increase in proportion to advancing age, thereby imposing a significant challenge to the cardiovascular system. A total of 30 participants of both sexes (age range from 20-55 y, 37% women) underwent a detailed medical examination, and their maximal oxygen uptake was determined. They performed a squat exercise (2 sets × 7 repetitions) on a flywheel ergometer at three randomly assigned moments of inertia set at 0.025, 0.05, and 0.075 kg m², while the cardiovascular response was continuously recorded via a Task force monitor. Compared to the resting values, robust rises in the MAP were observed during all three flywheel loads, reaching the highest value of 179 ± 4 mmHg (p = 0.001) during the highest load. In parallel, the cardiac index (cardiac output normalized by the body surface area) was two-fold greater during all the flywheel loads compared to rest, and at a high load, exclusively, the total peripheral resistance increased by 11% (p = 0.001). The rise in heart rate compensated for a load-dependent drop in the stroke index (stroke volume normalized by the body surface area). In our study population, no correlations were observed between the relative increase in the MAP and the participants' age for the three flywheel loads. The present findings suggest that the larger moments of inertia impose a substantial burden to the cardiovascular system, without apparent associated age-differences of the relative magnitude of MAP rise throughout the exercise.

Blood Pressure Response and Vascular Function of Professional Athletes and Controls

Workload-indexed blood pressure response (wiBPR) to exercise has been shown to be superior to peak systolic blood pressure (SBP) in predicting mortality in healthy men. Thus far, however, markers of wiBPR have not been evaluated for athletes and the association with vascular function is unclear. We examined 95 male professional athletes (26±5 y) and 30 male controls (26±4 y). We assessed vascular functional parameters at rest and wiBPR with a graded bicycle ergometer test and compared values for athletes with those of controls. Athletes had a lower pulse wave velocity (6.4±0.9 vs. 7.2±1.5 m/s, p=0.001) compared to controls. SBP/Watt slope (0.34±0.13 vs. 0.44±0.12 mmHg/W), SBP/MET slope (6.2±1.8 vs. 7.85±1.8 mmHg/MET) and peak SBP/Watt ratio (0.61±0.12 vs. 0.95±0.17 mmHg/W) were lower in athletes than in controls (p<0.001). The SBP/Watt and SBP/MET slope in athletes were comparable to the reference values, whereas the peak SBP/Watt-ratio was lower. All vascular functional parameters measured were not significantly correlated to the wiBPR in either athletes or controls. In conclusion, our findings indicate the potential use of the SBP/Watt and SBP/MET slope in pre-participation screening of athletes. Further, vascular functional parameters, measured at rest, were unrelated to the wiBPR in athletes and controls.

Sex differences in workload-indexed blood pressure response and vascular function among professional athletes and their utility for clinical exercise testing

Purpose

Sex differences in blood pressure (BP) regulation at rest have been attributed to differences in vascular function. Further, arterial stiffness predicts an exaggerated blood pressure response to exercise (BPR) in healthy young adults. However, the relationship of vascular function to the workload-indexed BPR and potential sex differences in athletes are unknown.

Methods

We examined 47 male (21.6 ± 1.7 years) and 25 female (21.1 ± 2 years) athletes in this single-center pilot study. We assessed vascular function at rest, including systolic blood pressure (SBP). Further, we determined the SBP/W slope, the SBP/MET slope, and the SBP/W ratio at peak exercise during cycling ergometry.

Results

Male athletes had a lower central diastolic blood pressure (57 ± 9.5 vs. 67 ± 9.5 mmHg, p < 0.001) but a higher central pulse pressure (37 ± 6.5 vs. 29 ± 4.7 mmHg, p < 0.001), maximum SBP (202 ± 20 vs. 177 ± 15 mmHg, p < 0.001), and ΔSBP (78 ± 19 vs. 58 ± 14 mmHg, p < 0.001) than females. Total vascular resistance (1293 ± 318 vs. 1218 ± 341 dyn*s/cm⁵, p = 0.369), pulse wave velocity (6.2 ± 0.85 vs. 5.9 ± 0.58 m/s, p = 0.079), BP at rest (125 ± 10/76 ± 7 vs. 120 ± 11/73.5 ± 8 mmHg, p > 0.05), and the SBP/MET slope (5.7 ± 1.8 vs. 5.1 ± 1.6 mmHg/MET, p = 0.158) were not different. The SBP/W slope (0.34 ± 0.12 vs. 0.53 ± 0.19 mmHg/W) and the peak SBP/W ratio (0.61 ± 0.12 vs. 0.95 ± 0.17 mmHg/W) were markedly lower in males than in females (p < 0.001).

Conclusion

Male athletes displayed a lower SBP/W slope and peak SBP/W ratio than females, whereas the SBP/MET slope was not different between the sexes. Vascular functional parameters were not able to predict the workload-indexed BPR in males and females.