Increased mean arterial pressure response to dynamic exercise in normotensive subjects with multiple metabolic risk factors

Lower vascular conductance responses to handgrip exercise are improved following acute antioxidant supplementation in young individuals with post-traumatic stress disorder

Young individuals with post-traumatic stress disorder (PTSD) display peripheral vascular and autonomic nervous system dysfunction, two factors potentially stemming from a redox imbalance. It is currently unclear if these aforementioned factors, observed at rest, alter peripheral haemodynamic responses to exercise in this population. This study examined haemodynamic responses to handgrip exercise in young individuals with PTSD following acute antioxidant (AO) supplementation. Thirteen young individuals with PTSD (age 23 ± 3 years), and 13 age- and sex-matched controls (CTRL) participated in the study. Exercise-induced changes to arm blood flow (BF), mean arterial pressure (MAP) and vascular conductance (VC) were evaluated across two workloads of rhythmic handgrip exercise (3 and 6 kg). The PTSD group participated in two visits, consuming either a placebo (PL) or AO prior to their visits. The PTSD group demonstrated significantly lower VC (P = 0.04) across all exercise workloads (vs. CTRL), which was significantly improved following AO supplementation. In the PTSD group, AO supplementation improved VC in participants possessing the lowest VC responses to handgrip exercise, with AO supplementation significantly improving VC responses (3 and 6 kg: P < 0.01) by blunting elevated exercise-induced MAP responses (3 kg: P = 0.01; 6 kg: P < 0.01). Lower VC responses during handgrip exercise were improved following AO supplementation in young individuals with PTSD. AO supplementation was associated with a blunting of exercise-induced MAP responses in individuals with PTSD displaying elevated MAP responses. This study revealed that young individuals with PTSD exhibit abnormal, peripherally mediated exercise responses that may be linked to a redox imbalance.

Can Post-Exercise Hemodynamic Response Be Influenced by Different Recovery Methods in Paraplegic Sportsmen?

Post-exercise hypotension is of great clinical relevance and also in sports training settings, as recovery speed is important. The aim of this study was to compare the influence of different recovery methods on post-exercise hemodynamic response. Twelve male paraplegic sportsmen (25.40 ± 3.30 years) performed a strength training (ST) session using the bench press exercise. After the ST, three recovery methods were randomly performed over a 15-min period: passive recovery (PR), cold-water (CW) and dry needle (DN). Blood pressure (BP), heart rate (HR) and myocardial oxygen were measured before and post ST, as well as post the recovery method. Results: Dry needling induced lower systolic blood pressure (SBP) immediately after the treatment when compared with the other recovery methods, but the contrary was observed at 50 and 60-min post recovery, where records with DN exhibit higher mean values (η²p = 0.330). There were no differences in post-exercise diastolic BP and mean BP between recovery methods. There was a significantly higher HR after the PR method, when compared with CW and with DN (η²p = 0.426). The same was observed for double product and for myocardial oxygen, though with a larger effect size (η²p = 0.446). We conclude that dry needling seems to induce a faster SBP lowering immediately after the procedure but at 50-min post procedure the cold-water method showed better result. As for HR, both procedures (DN and CW) showed a better recovery when compared with passive recovery, along the several moments of measurement.

The effect of oral glucose tolerance testing on changes in arterial stiffness and blood pressure in elderly women with hypertension and relationships between the stage of diabetes and physical fitness levels

[Purpose]

The purpose of this study was to assess changes in blood glucose level, blood pressure, and arterial stiffness after a 75 g oral glucose tolerance test (OGTT) in elderly women aged over 65 years with hypertension and either normal glycemic control, impaired fasting glucose tolerance, or diabetes mellitus. We also wished to investigate the relationship between stages of diabetes and physical fitness.

[Methods]

A total of 24 elderly women with hypertension were assigned to a control group (CON; n=7), impaired fasting glucose group (IFG; n=9), and diabetes mellitus group (DM; n=8). In each group, blood glucose level, brachial ankle pulse wave velocity (PWV), and blood pressure were measured at baseline as well as 60 and 120 minutes after a 75 g OGTT. Physical fitness factors such as hand grip strength, balance test, 4 m gait speed test, chair stand test, short physical performance battery, and 6-minute walking test were subsequently assessed.

[Results]

In all three groups, blood glucose levels were significantly increased at 60 and 120 minutes after a 75 g OGTT. In the DM group, blood glucose levels were significantly higher before and after a 75 g OGTT than in the CON group. In the CON group, PWV was significantly increased at 60 minutes after a 75 g OGTT; however, there were no changes in other groups after glucose ingestion. In the CON group, systolic and diastolic blood pressures were significantly decreased at 60 and 120 minutes after a 75 g OGTT compared to baseline. However, there was no change in blood pressure after ingestion in the DM group. The IFG group had greater grip strength than the CON group; however, there were no differences in other variables between the groups.

[Conclusion]

After a 75 g OGTT, elderly women with hypertension and diabetes maintain higher blood glucose levels compared to those with hypertension alone. Unlike elderly women with hypertension alone, those with hypertension and diabetes did not show changes in arterial stiffness and blood pressure after a 75 g OGTT. Therefore, elderly women with hypertension and diabetes may not be able to control their blood vessels following a 75 g OGTT due to impaired vascular endothelial function. Moreover, there was no association between diabetes stage and physical fitness in elderly women with hypertension.

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

BACKGROUND

This study was designed to evaluate the possible association between an exaggerated blood pressure (BP) response to exercise and subclinical vascular impairment in normotensive individuals.

METHODS

The study participants consisted of 92 untreated normotensive men (aged 42 ± 9 years) without a history of cardiovascular disease or stroke. A graded exercise test was conducted using a bicycle ergometer, and the mean arterial pressure (MAP) during submaximal exercise was evaluated. The brachial-ankle pulse wave velocity (baPWV) was measured as an index of arterial stiffness. The second peak of radial systolic BP (SBP2) was used as an estimate of central BP. The albumin-to-creatinine ratio (ACR) values were determined as the mean of two nonconsecutive spot urine specimens.

RESULTS

Compared with individuals with a normal response (MAP z-score < +1.0, n = 60), those with an exaggerated BP response to exercise (MAP z-score ≥ +1.0, n = 32) exhibited significantly higher baPWV (1412 ± 158 vs. 1250 ± 140 cm/s), radial SBP2 (122 ± 11 vs. 106 ± 13 mmHg), and greater log-ACR (0.93 ± 0.30 vs. 0.59 ± 0.23 mg/gCre). Multiple regression analysis revealed that an exaggerated BP response to exercise was significantly associated with baPWV (β = 0.198, P= .043), radial SBP2 (β = 0.156, P = .049), and log-ACR (β = 0.276, P = .006) independent of potential confounding factors.

CONCLUSIONS

These results suggest that subclinical vascular impairment is associated with an exaggerated increase in BP during exercise even in the absence of clinical hypertension.

Effect of Metaboreflex on Cardiovascular System in Subjects of Metabolic Syndrome

INTRODUCTION

Metaboreflex is a reflex in which muscle receptors send signals regarding metabolic (metabolites accumulation like lactic acid, potassium, adenosine) conditions of the muscles to nucleus tractus solitarius via afferent III and IV fibres to cause haemodynamic adjustments in order to regulate blood flow on the basis of the status of contracting muscle. Dysregulation in its mechanism in metabolic syndrome is demonstrated.

AIM

To study the effect of metaboreflex by both isometric and rhythmic handgrip exercise on CVS parameters {Blood Pressure (BP), Cardiac Output (CO) and Systemic Vascular Resistance (SVR)} in subjects of metabolic syndrome.

MATERIALS AND METHODS

In this study, 27 subjects aged 25 to 45 years were enrolled after ethical clearance and proper consent. They were divided into: a) subjects without metabolic syndrome; and b) subjects with metabolic syndrome. Impedance cardiovasography was done to assess cardiac parameters (systolic and diastolic blood pressure, cardiac output, systemic vascular resistance). Pre-exercise parameters were assessed followed by isometric exercise and post-isometric exercise parameter measurement. Again after rest, rhythmic exercise was followed. Finally post exercise parameters were assessed. Student paired t-test for comparison between pre and post exercise parameters were done.

RESULTS

Changes in diastolic BP following exercise were statistically significant in subjects without metabolic syndrome (p-value 0.01 and 0.001 following isometric and rhythmic exercise respectively). In subjects with metabolic syndrome also these changes were significant, but to a lesser extent (p-value 0.1 and 0.01 respectively for isometric and rhythmic exercise). Changes in systolic BP following exercise were statistically significant in subjects without metabolic syndrome (p-value 0.001 and 0.001 following isometric and rhythmic exercise respectively). In subjects with metabolic syndrome also these changes were significant (p-value 0.01 and 0.001 respectively for isometric and rhythmic exercise).

CONCLUSION

Diminished pressor response is found after exercise in subjects with metabolic syndrome.

Acute Effects of Exercise on Blood Pressure: A Meta-Analytic Investigation

Hypertension affects 25% of the world's population and is considered a risk factor for cardiovascular disorders and other diseases. The aim of this study was to examine the evidence regarding the acute effect of exercise on blood pressure (BP) using meta-analytic measures. Sixty-five studies were compared using effect sizes (ES), and heterogeneity and Z tests to determine whether the ES were different from zero. The mean corrected global ES for exercise conditions were -0.56 (-4.80 mmHg) for systolic BP (sBP) and -0.44 (-3.19 mmHg) for diastolic BP (dBP; z ≠ 0 for all; p < 0.05). The reduction in BP was significant regardless of the participant's initial BP level, gender, physical activity level, antihypertensive drug intake, type of BP measurement, time of day in which the BP was measured, type of exercise performed, and exercise training program (p < 0.05 for all). ANOVA tests revealed that BP reductions were greater if participants were males, not receiving antihypertensive medication, physically active, and if the exercise performed was jogging. A significant inverse correlation was found between age and BP ES, body mass index (BMI) and sBP ES, duration of the exercise's session and sBP ES, and between the number of sets performed in the resistance exercise program and sBP ES (p < 0.05). Regardless of the characteristics of the participants and exercise, there was a reduction in BP in the hours following an exercise session. However, the hypotensive effect was greater when the exercise was performed as a preventive strategy in those physically active and without antihypertensive medication.

Glucose and the risk of hypertension in first-degree relatives of patients with type 2 diabetes

To test the hypothesis that plasma glucose (PG) levels is associated with the incidence of hypertension (HT) in nondiabetic and non-hypertensive first-degree relatives (FDR) of people with type 2 diabetes (T2D). A total of 1089 FDR without diabetes and/or HT of consecutive patients with T2D 30-70 years old were examined and followed for a mean (s.d.) of 6.9 (1.7) years for HT incidence. At baseline and through follow-up, participants underwent a standard 75 gm 2-h oral glucose tolerance test. HT was defined according to the criteria of the Seventh Report of Joint National Committee. We used Cox proportional hazard models to estimate hazard ratio for incident HT and plotted a receiver operating characteristic curve to assess discrimination. The PG levels at baseline were associated with incidence of HT, independently of age, gender, obesity and high cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, education and systolic blood pressure. Those with impaired glucose tolerance were 54% (hazard ratio 1.54; 95% confidence interval (CI) 1.33, 1.77) more likely to develop HT than those with normal glucose tolerance. Those with impaired fasting glucose were also 23% (hazard ratio 1.23; 95% CI 1.01, 1.50) more likely to develop HT. High PG levels were consistently associated with incident HT.

Exercise-mediated vasodilation in human obesity and metabolic syndrome: effect of acute ascorbic acid infusion

We tested the hypothesis that infusion of ascorbic acid (AA), a potent antioxidant, would alter vasodilator responses to exercise in human obesity and metabolic syndrome (MetSyn). Forearm blood flow (FBF, Doppler ultrasound) was measured in lean, obese, and MetSyn adults (n = 39, 32 ± 2 yr). A brachial artery catheter was inserted for blood pressure monitoring and local infusion of AA. FBF was measured during dynamic handgrip exercise (15% maximal effort) with and without AA infusion. To account for group differences in blood pressure and forearm size, and to assess vasodilation, forearm vascular conductance (FVC = FBF/mean arterial blood pressure/lean forearm mass) was calculated. We examined the time to achieve steady-state FVC (mean response time, MRT) and the rise in FVC from rest to steady-state exercise (Δ, exercise - rest) before and during acute AA infusion. The MRT (P = 0.26) and steady-state vasodilator responses to exercise (ΔFVC, P = 0.31) were not different between groups. Intra-arterial infusion of AA resulted in a significant increase in plasma total antioxidant capacity (174 ± 37%). AA infusion did not alter MRT or steady-state FVC in any group (P = 0.90 and P = 0.85, respectively). Interestingly, higher levels of C-reactive protein predicted longer MRT (r = 0.52, P < 0.01) and a greater reduction in MRT with AA infusion (r = -0.43, P = 0.02). We concluded that AA infusion during moderate-intensity, rhythmic forearm exercise does not alter the time course or magnitude of exercise-mediated vasodilation in groups of young lean, obese, or MetSyn adults. However, systemic inflammation may limit the MRT to exercise, which can be improved with AA.

Mechanical and metabolic reflex activation of the sympathetic nervous system in younger adults with metabolic syndrome

AIM

Based on reports of exaggerated blood pressure responses to whole-body exercise in patients with metabolic syndrome (MetSyn), we tested the hypothesis that MetSyn adults would exhibit augmented sympathetic and pressor responses to mechanoreflex and metaboreflex activation when compared with healthy, age-matched control subjects.

METHODS

We studied 12 adults with MetSyn (34±3years) and 12 healthy control subjects (34±3years). Heart rate (HR; ECG), blood pressure (BP; finger photoplethysmography), and MSNA (microneurography of the peroneal nerve) were measured during: (1) static handgrip exercise at 15% of maximal voluntary contraction (MVC), and (2) static handgrip exercise at 30% MVC to fatigue, followed by post-exercise ischemia (PEI). Increases in MSNA, HR, and BP were assessed.

RESULTS

During static exercise at both 15 and 30% MVC, increases in MSNA, HR, and BP were not different between groups. MSNA remained significantly elevated from baseline during PEI and responses were not different between groups.

CONCLUSION

Sympathetic and pressor responses to mechanoreflex and metaboreflex activation are not augmented in younger adults with MetSyn.