Analysis of Cardiovascular Hemodynamic and Autonomic Variables in Individuals with Systemic Arterial Hypertension, Type 2 Diabetes Mellitus, and Parkinson's Disease: A Comparative Study.

BACKGROUND: Systemic arterial hypertension (SAH), type 2 diabetes mellitus (T2DM), and Parkinson's disease (PD) are highly prevalent chronic diseases that can significantly impact the cardiovascular system. AIM: The aim of this study was to compare hemodynamic and autonomic variables at rest in individuals with SAH, T2DM, or PD. METHODS: Fifty sedentary or insufficiently active individuals (22 men) with SAH (age = 66 ± 5.0 yr), T2DM (age = 52 ± 10 yr) or PD (age = 68 ± 8.0 yr) had their resting blood pressure (BP), arterial stiffness, endothelial function, and heart rate variability (HRV) assessed and compared. RESULTS: Systolic and diastolic BP were higher in SAH (130 ± 10 / 80 ± 10 mmHg) than T2DM (110 ± 14 / 75 ± 11 mmHg) and PD, and (123 ± 20 / 70 ± 11 mmHg) respectively. T2DM individuals showed lower arterial stiffness (8.4 ± 1.1 m/s), when compared to SAH (10.3 ± 2.3 m/s) and PD (10.6 ± 3.0 m/s). T2DM had greater resting tachycardia showed by the mean RR (759 ± 79 ms), than SAH (962 ± 169 ms) and PD (976 ± 134 ms), which was accompanied by higher sympathetic modulation (low frequency [LF]: 62 ± 19 nu) and lower parasympathetic modulation (high frequency [HF]: 32 ± 16 nu) when compared to SAH (LF: 40 ± 16 nu; HF: 61 ± 33 nu). No differences among groups were found on non-linear HRV markers and endothelial reactivity indexes. CONCLUSIONS: Individuals with T2DM showed impaired levels of cardiac autonomic markers when compared to individuals with SAH and PD, despite of having lower levels of BP and arterial stiffness.

Acute high-intensity interval exercise versus moderate-intensity continuous exercise in heated water-based on hemodynamic, cardiac autonomic, and vascular responses in older individuals with hypertension.

OBJECTIVES: This crossover study design aimed to assess hemodynamic, cardiac autonomic, and vascular responses to high-intensity interval (HIIE) vs moderate-intensity continuous exercise (MICE) in older individuals with hypertension. METHODS: Twenty (67 ± 7 y) older individuals with hypertension were randomly assigned to perform HIIE, MICE, or control (CON) sessions in the heated swimming pool (30-32°C). Blood pressure (BP), arterial stiffness, endothelial reactivity, and heart rate variability (HRV) were measured pre, post, and 45 min (recovery) after each intervention followed by 24-h ambulatory BP and HRV. RESULTS: One single aerobic exercise session was not effective to provoke post-exercise hypotension and vascular improvements. HIIE was superior to MICE and CON to increasing parasympathetic modulation at post and recovery. Exercise sessions showed to disturb the autonomic system at nighttime compared to CON. CONCLUSIONS: These results may have important implications in water-based therapy and the elderly with hypertension.

Effects of inspiratory muscle-training intensity on cardiovascular control in amateur cyclists.

Chronic effects of inspiratory muscle training (IMT) on autonomic function and baroreflex regulation are poorly studied. This study aims at evaluating chronic effects of different IMT intensities on cardiovascular control in amateur cyclists. A longitudinal, randomized, controlled blind study was performed on 30 recreational male cyclists undergoing IMT for 11 wk. Participants were randomly allocated into sham-trained group (SHAM, n = 9), trained group at 60% of the maximal inspiratory pressure (MIP60, n = 10), and trained group at critical inspiratory pressure (CIP, n = 11). Electrocardiogram, finger arterial pressure, and respiratory movements were recorded before (PRE) and after (POST) training at rest in supine position (REST) and during active standing (STAND). From the beat-to-beat series of heart period (HP) and systolic arterial pressure (SAP), we computed time domain markers, frequency domain indexes in the low frequency (0.04-0.15 Hz) and high frequency (HF, 0.15-0.4 Hz) bands, an entropy-based complexity index (CI), and baroreflex markers estimated from spontaneous HP-SAP sequences. Compared with SHAM, the positive effect of MIP60 over the HP series led to the HF power increase during REST (PRE: 521.2 ± 447.5 ms2; POST: 1,161 ± 878.9 ms2) and the CI rise during STAND (PRE: 0.82 ± 0.18; POST: 0.97 ± 0.13). Conversely, the negative effect of CIP took the form of the decreased HP mean during STAND (PRE: 791 ± 71 ms; POST: 737 ± 95 ms). No effect of IMT was visible over SAP and baroreflex markers. These findings suggest that moderate-intensity IMT might be beneficial when the goal is to limit cardiac sympathetic hyperactivity at REST and/or in response to STAND.

Cardiac baroreflex hysteresis is one of the determinants of the heart period variability asymmetry.

In heart period (HP) variability (HPV) recordings the percentage of negative HP variations tends to be greater than that of positive ones and this pattern is referred to as HPV asymmetry (HPVA). HPVA has been studied in several experimental conditions in healthy and pathological populations, but its origin is unclear. The baroreflex (BR) exhibits an asymmetric behavior as well given that it reacts more importantly to positive than negative arterial pressure (AP) variations. We tested the hypothesis that the BR asymmetry (BRA) is a HPVA determinant over spontaneous fluctuations of HP and systolic AP (SAP). We studied 100 healthy subjects (age from 21 to 70 yr, 54 men) comprising 20 subjects in each age decade. Electrocardiogram and noninvasive AP were recorded for 15 min at rest in supine position (REST) and during active standing (STAND). The HPVA was evaluated via Porta's index and Guzik's index, while the BRA was assessed as the difference, and normalized difference, between BR sensitivities computed over positive and negative SAP variations via the sequence method applied to HP and SAP variability. HPVA significantly increased during STAND and decreased progressively with age. BRA was not significantly detected both at REST and during STAND. However, we found a significant positive association between BRA and HPVA markers during STAND persisting even within the age groups. This study supports the use of HPVA indexes as descriptors of BRA and identified a challenge soliciting the BR response like STAND to maximize the association between HPVA and BRA markers.